Coast Artillery Gunners' Instruction, Antiaircraft Searchlight Batteries, First and Second Class Gunners

[Coast Artillery Gunners' Instruction, Antiaircraft Searchlight Batteries, First and Second Class Gunners]
[From the U.S. Government Publishing Office, www.gpo.gov]

W 1.35 \ 4-330
TM 4-330
WAR DEPARTMENT
TECHNICAL MANUAL

December 3, 1941
ana
NON-CIRCULATING
NTSU LIBRARY
Document Reserve
COAST ARTILLERY GUNNERS’ INSTRUCTION, ANTIAIRCRAFT SEARCHLIGHT BATTERIES, FIRST AND SECOND CLASS GUNNERS
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’IXAb H . V TM 4-330
LIBRARY
TECHNICAL MANUAL
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COAST ARTILLERY GUNNERS’ INSTRUCTION, ANTIAIRCRAFT SEARCHLIGHT BATTERIES, FIRST AND SECOND CLASS GUNNERS
Changes I WAR DEPARTMENT,
No. 1 J Washing! on 25, D. C., 16 July 1943.
TM 4-330, Coast Artillery Gunners’ Instruction, Antiaircraft Searchlight Batteries, First and Second Class Gunners, 3 December 1941, is rescinded.
[A. G. 300.7 (6 Jul 43).] (C 1, 16 Jul 43.)
By order of the Secretary of War :
G. C. MARSHALL,
Chief of Staff.
Official :
J. A. ULIO,
Major General,
The Adjutant General.
542117°—43
D. S. GOVERNMENT PRINTING OFFICE: 1943
TM 4-330
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TECHNICAL MANUAL! WAR DEPARTMENT,
No. 4-330 | Washington, December 3, 1941.
COAST ARTILLERY GUNNERS’ INSTRUCTION, ANTIAIRCRAFT SEARCHLIGHT BATTERIES, FIRST AND SECOND CLASS GUNNERS
Prepared under direction of the Chief of Coast Artillery
Paragraphs
Chapter 1. General_____________________________________ 1-2
Chapter 2. Drill of searchlight section________________ 3-7
Chapter 3. Nomenclature of various parts of searchlight section equipment.
Section I. Sperry searchlight equipment_____________ 8-10
II. General Electric searchlight equipment___ 11-13
III. Sound locators___________________________ 14-16
Chapter 4. Care and operation of searchlight section equipment.
Section I. Power plant_________________________________ 17-21
II. Searchlight___________;__________________ 22-28
III. Control stations____________________________ 29-35
IV. Sound locator apparatus_____________________ 36-40
Chapter 5. Use and care of telephones__________ 41-42
Chapter 6. Motor transportation________________ 43-48
Chapter 7. Elementary definitions for antiaircraft artillery 49-50
Chapter 8. Nomenclature, action, and maintenance of
small arm with which organization is equipped and its ammunition_______________ 51-53
Chapter 9. Cordage and mechanical maneuvers________ __ 54-64
Chapter 10. Indication, identification, and characteristic features of classes of aircraft__________________________ 65-68
Page
Index____________________________________________________ 199
Chapter 1
GENERAL
Paragraph
Purpose and scope__________________________________________________ 1
Assignment of topics________________________________________________ 2
1. Purpose and scope.—a. Purpose.—This manual is designed primarily for use by organization commanders in the instruction of
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enlisted men of antiaircraft searchlight units of the Coast Artillery Corps. It may be used by officers conducting examinations of enlisted men for qualification as gunners, as contemplated by FM 4—150. The questions and answers in the manual are intended merely as a guide and should be supplemented by the extensive use of other questions and answers and by practical demonstrations.
A Scope.—The topics included in this manual are those prescribed in FM 4—150 for qualification of enlisted men as first and second class gunners in antiaircraft searchlight units.
2. Assignment of topics.—The following is the general assignment of topics. Each organization should omit those portions of the assigned chapters, sections, and paragraphs that do not pertain to the particular equipment in use by the organization.
Subject
First class gunners
Second class gunners
Drill of searchlight section____________________________
Nomenclature of various parts of _______________________
searchlight.
Nomenclature of various parts of _______________________
sound locator apparatus.
Cordage and mechanical maneuvers________________________
Nomenclature, action, and mainte- ______________________
nance of small arm with which the
organization is equipped, and its ammunition.
Motor transportation___________________
Care and operation of power plant______
Care and operation of searchlight______
Care and operation of sound locator apparatus.
Use and care of telephones_____________
Elementary definitions for antiaircraft artillery.
Indication, identification, and characteristic features of the several classes of aircraft.
Chapter 2.
Chapter 3, sections I and II.
Chapter 3, section
III.
Chapter 9.
Chapter 8.
Chapter 6, pars. 43 and 44.
Chapter 6, pars. 45-49, incl.
Chapter 4, section I.
Chapter 4, sections II and III.
Chapter 4, section IV.
Chapter 5.
Chapter 7.
Chapter 10.
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 3-4
Chapter 2
DRILL OF SEARCHLIGHT SECTION
Paragraph
Organization------------------------------------------------- 3
Prepare for action_____________________________________________ 4
Examine equipment-------------------------------------------- 5
Commands of rest, stand by, track, in action, out of action, change target, and march order--------------------------------------------- 6
Drill table---------------------------------------------------- 7
3. Organization.—Instruction in drill will be practical, the candidate performing the duties of such members of the searchlight section as the examining board may direct. (See drill table at end of manual.)
Q. Of what personnel does the searchlight section consist? A. The searchlight section consists of one chief of section (a sergeant) ; one searchlight commander (a corporal) ; and ten privates, as follows: No. 1, azimuth listener; No. 2, elevation listener; No. 3, acoustic corrector operator; No. 4, telephone operator; No. 5, azimuth controller; No. 6, elevation controller; No. 7, searchlight operator; No. 8, power plant operator and chauffeur, Truck No. 2; No. 9, chauffeur. Truck No. 1; No. 10, basic, assistant to No. 8.
Q. What are the names of the squads in the searchlight section? A.
(1) The^sound locator squad.
(2) The searchlight squad.
Q. Of what personnel does the sound locator squad consist? A. See figure 1.
Q. Of what personnel does the searchlight squad consist?—A. See figure 1.
4. Prepare for action.—Q. Who gives the command prepare for action? A. The chief of section gives the command prepare for action after the trucks of the section have reached the vicinity of the searchlight position. The command is repeated by the searchlight commander.
Q. What is done after the command prepare for action is given? A. The chief of section designates the positions at which the searchlight, control station, power plant, and sound locator are to be placed. Truck No. 1 is driven to the searchlight position by No. 9, after which Nos. 1, 2, 5, 7, and 9 unload, set up, and level the searchlight under supervision of the chief of section. No. 7, searchlight operator, remains at the searchlight, connecting yellow, red, and blue cables to
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the junction box after they have been delivered by truck No. 2. and otherwise prepares the light for action. No. 7 also removes the extended hand controller from truck No. 1 and places it close to the searchlight.
""---- Sound locator squad ----—1~*------ Searchlight squad —--------------
________ ___________ l
1 3 | 5 7 9
] _______ 40
chief of Li_j ~z ; । Light rp “| ; i ~~i '"p
Section Pace । Comdr, ___________ ° 'u I
Figure 1. Formation of personnel of antiaircraft searchlight section.
Q. After the searchlight is in position, what is done? A. Truck No. 1 proceeds to the control station position under supervision of the chief of section. Nos. 1, 2, and 5 set up the control station. No.
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TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 4
5 procures the automatic rifle from the truck, places it near the control station, and then levels the control station. When the red cable is delivered by truck No. 2, he connects it to the control station.
Q. Where does Truck No. 1 go next? A. Truck No. 1 then goes to the sound locator position where Nos. 1, 2, and 9 unload and set up the sound locator under the supervision of the chief of section. No. 1 connects the blue cable to the sound locator after truck No. 2 has delivered the cable to the sound locator position. Nos. 1 and 2 level the sound locator. No. 2 installs the pantograph and drives stakes to indicate the direction of advanced listening posts and the other four-searchlights of the platoon. No. 9 then drives the truck to the parking area selected by the chief of section, checks his truck, and then performs duties as indicated by the chief of section.
Q. What does truck No. 2 do at the command prepare for action?
A. After finding out where the equipment is to be located, No. 8 drives truck No. 2 to the power plant position, where Nos. 3, 6, 8, and 10 unload the power plant. No. 8, the power plant operator, places the automatic weapon near the power plant. Nos. 3 and 6 carry the power cable reel to the rear of the truck and pay out the positive and negative yellow power cables as truck No. 2 moves toward the searchlight position. No. 10 holds the power cables in place as truck No. 2 moves off. and then connects the cables to the power plant. Thereafter No. 10 performs duties as indicated by the chief of section. When truck No. 2 arrives at the searchlight, the power cable reel is moved out of the way and the red and blue cable reels are moved to the rear of the truck. The truck then moves toward the control station, paying out the red cable. If the sound locator is located so that blue cable to it may also be payed out, this is done at the same time, otherwise, each cable is laid separately. When both are laid at the same time, No. 3 pays out the blue cable and the searchlight commander the red cable. No. 6 walks behind the truck, forcing both cables to one side so as to allow passage for vehicles without damage to the cables. If each cable is payed out separately, No. 3 pays out both red and blue cables; the searchlight commander assists either No. 3 or No. 6, as he thinks necessary. After the cables are laid, truck No. 2 is driven to the prescribed parking area by No. 8, who checks his truck and thereafter performs duties as indicated by the chief of section. Nos. 3 and 6 proceed to the sound locator and control station positions, respectively.
Q. What are the duties of No. 4, the telephone operator, at the command prepare for action? A. After learning from the chief of section where the telephone line is located, he leaves truck No. 2
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COAST ARTILLERY CORPS
and proceeds on foot to connect his telephone to establish communication with platoon headquarters. When this is accomplished he reports to the chief of section.
Q. Do the personnel of truck No. 2 wait until the duties of the personnel of truck No. 1 are completed before starting their duties? A. No. The personnel of truck No. 2 perform their duties at the same time to avoid unnecessary delay.
5. Examine equipment.—Q. Who gives the command examine equipment? A. The chief of section gives the command examine equipment as soon as all equipment is placed properly and cables are connected.
Q. What is done at the sound locator at the command examine equipment? A. The chief of section verifies the proper functioning of all equipment and personally supervises the orientation and synchronization of the unit. Nos. 1 and 2 test the elevating and traversing mechanisms, and verify that the sound locator is leveled. Nos. 1, 2, and 3 then orient the sound locator. No 3 inspects the acoustic corrector, is given the parallax correction by the chief of section and sets it on the parallax cam scale, and assists Nos. 1 and 2 with the orientation. No. 2 also tests the cut-out switch which reduces noise from the data transmitters. Nos. 1 and 2 then adjust their listening helmets for fit, and as a test connect each helmet properly to the aluminum elbows fixed to the flexible tubing from the horns. No. 4 tests communication to the platoon command post. Any failure of equipment to function properly is reported to the chief of section.
Q. What is done at the control station at the command examine equipment? A. The searchlight commander inspects the proper functioning of the searchlight, power plant, and control station. He directs the orientation and synchronization of the searchlight and control station with the sound locator. Nos. 5, 6, and 7 assist in the orientation and synchronization. Nos. 5 and 6 inspect the azimuth and elevation control mechanisms, and also test the distant electric control (D. E. C.) in azimuth and elevation, respectively. No. 5 inspects the automatic rifle to include the proper supply of ammunition. No. 6 tests the buzzer by means of the buzzer signal switch.
Q. What is done at the searchlight when the command examine equipment is given ? A. No. 7 inspects all cable connections and the proper leveling of the searchlight. He then assures himself that the dynamotor is functioning, that the lamp is carboned, and that spare carbons are on hand. When the power is delivered from the power plant he tests the proper functioning of the lamp mechanism and feeding of the carbons. Important: No. 7 assures himself that
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TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 5-6 the arc is functioning properly, carbons are positioned properly, and that the arc operates at 78 volts with 150 amperes flowing through it PROVIDED THE PLATOON COMMANDER AUTHORIZES THIS ACTION. (Striking the arc may give away the searchlight position at night.) The searchlight commander, assisted by No. 7, orients and synchronizes the searchlight. Nos. 5 and 6, at the control station, assist in these operations.
Q. What is done at the power plant at the command examine equipment? A. No. 8 examines the power plant. He inspects the oil, water, and gasoline supply to insure a sufficient supply, and assures himself that cables are connected properly. No. 8 then proceeds to start the engine and adjust the generator voltage. (See Operator’s Manual, which is furnished with each power plant, for exact procedure. No. 8 has an importamt position and must thoroughly familiarize himself with the operation of the power plamt.) When No. 7 is permitted to strike the arc, a more exact adjustment of the voltage and current may be made by No. 8, since No. 7 can tell No. 8 what voltage and current are delivered to the searchlight. No. 8 also examines the automatic rifle and assures himself that a sufficient supply of ammunition is on hand.
Q. What do Nos. 9 and 10 do at this time? A. No. 9, after driving truck No. 1 to the prescribed parking area, checks the water, gasoline, oil, and operation of his truck. After truck No. 2 is parked in the prescribed parking area, No. 10 inspects it for water, gasoline, oil, and correct operation. Nos. 9 and 10 check concealment of their respective trucks. No. 10 then assists No. 8 at the power plant.
6. Commands of rest, stand by, track, in action, out of action, change target, and march order.—Q. Who gives the command rest, and what is done? A. If no action is probable, or when ordered by the platoon commander, the chief of section commands REST. The command is repeated by the searchlight commander. During rest periods, the chief of section arranges men in reliefs for the necessary posts as shown in the drill table under column headed REST.
Q. What is done at the command stand by? A. This command is given by the chief of section when a target is detected, when an adjacent light goes into action, or when he receives the order stand by from the platoon commander. The order is repeated by the search-- light commander. At this command all men of the searchlight section are alerted and take their respective posts, performing the duties outlined in the drill table under column headed stand by.
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Q. What is done at the command track? A. This command is given by the chief of section when the sound locator crew report "On target.” The command is repeated by the searchlight commander. Each man performs his duties so that the light may go into action at the proper command. See drill table under column headed track for duties performed by each member of the section.
Q. Who gives the command in action and what is done? A. Idle chief of section gives this command. It is repeated by the searchlight commander who signals No. 7, using the buzzer. No. 7 then closes the arc switch. Exact duties for each man appear under the column headed in action in the drill table.
Q. Who gives the command our of action, and what is done at this command? A. 'Hie command is given by the chief of section. It is repeated by the searchlight commander who signals No. 7, using the buzzer, whereupon No. 7 opens the main arc switch and extinguishes the arc. Other duties are as listed in column headed out of action in the drill table.
Q. If a new target is assigned, what is the command to give? A. change target. The chief of section causes the sound locator and searchlight to pick up the new target as outlined in column headed change target in the drill table.
Q- Who gives the command march order? A. On order from the platoon command post, the chief of section gives this command. The duties performed are the opposite of those performed in prepare for action. Exact duties are listed in the drill table under the column MARCH ORDER.
7. Drill table.—See insert at back of manual.
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 8
Chapter 3
NOMENCLATURE OF VARIOUS PARTS OF SEARCHLIGHT SECTION EQUIPMENT
Paragraphs
Section I. Sperry searchlight equipment_____________________________ 8-10
II. General Electric searchlight equipment________________11-13
III. Sound locators----------------------------------------14-16
Section I
SPERRY SEARCHLIGHT EQUIPMENT
Paragraph
Searchlights--------------------------------------------------- 8
Control stations----------------------------------------------- 9
Power plants---------x----------------------------------------- 10
8. Searchlights.—Q. In learning the names of the various parts, what should you bear in mind? A. In addition to learning the names of the various parts, you should also find out for what purpose each part is used, and how it works.
Q. What are the operating voltage and current for the arc of the Sperry searchlights? A. The arc operates at a voltage of 78 volts and a current of 150 amperes.
Q. What is the maximum range of a searchlight? A. This depends on atmospheric conditions. An average value of 10,000 yards is given as an approximate maximum range under good conditions.
Q. Modern searchlights have metal mirrors. What shape or type of mirror is it? A. These mirrors are parabolic mirrors. This means that if a source of light is emitted from the focal point of the mirror, the rays of light are reflected in parallel rays of light.
Q. What is the beam candlepower (an ordinary candle is rated as 1 candlepower) of the Sperry searchlight? A. It is rated at 800 million candlepower.
Q. What causes such a great amount of light in the beam? A. This is caused by the burning of gases in the positive carbon crater.
Q. In general, how long do the positive and negative carbons burn? A. All carbons burn for approximately iy2 hours.
Q. In how many ways may the carbons be fed? A. Three: automatically, semiautomatically, or by hand.
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Q. How can you tell the positive carbon from the negative carbon? A. The positive carbon is longer and thicker than the negative carbon. When issued the positive carbon is 22 inches long and 0.633 inch in diameter; the negative carbon is 12 inches long and 0.434 inch in diameter.
Q. Which carbon burns out first? A. The positive carbon. For this reason the arc must be watched carefully so that the positive nose cap is not melted.
Q. Do all antiaircraft searchlights have an extended hand controller for pointing the light manually? A. Yes.
65 54 61 65 66 53 52
Figure 2.—Sperry M1941 antiaircraft searchlight (front quarter view).
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50 62
59
69
51
49
48
58
55
57
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 8
Q. Point out the various parts of the searchlight with which your unit is equipped. While pointing out each part, describe its use. A. See figures 2, 3, 4, and 5.
Note.—All Sperry searchlights are similar except as noted under columns headed “Part” and “Purpose or use.”
Part
13. Positive carbon---------
48. Rear drum____:----------
49. Elevation data receiver housing. (Not part of 1934 and M-VI lights. M-VI light has a transmitter instead of a receiver at this location.)
50. Ventilating motor and exhaust vent.
51. Ventilating fan intake vents.
52. Azimuth control motor__
53. Azimuth motor clutch lever.
54. Azimuth scale lamp_____
55. Junction box__________
56. Front drum_____________
57. Glass door_____________
58. Sliding panel__________
59. Arc view peep sight----
60. Ballast resistor________
61. Handhold plate.---------
62. Elevation daylight sights.
63. Lamp unit______________
64. Recarboning lamp_______
65. Steering tongue and lug...
66. Transportation bar_____
67. Azimuth daylight sights..
69. Orienting sights_______
Purpose or use
When burning, light comes from incandescent gas which forms in the positive crater.
Made of aluminum alloy, it houses and supports the metal mirror and the arc lamp column on which is mounted the lamp unit.
It houses the elevation data receiver which is connected electrically by cable to the sound locator elevation data transmitter. The receiver causes the elevation zero readers (one at the searchlight and one at the control station) to indicate elevation data. (For the M-VI light only: The transmitter sends data to the comparator giving the position of the light.)
This motor causes fresh air to be drawn into the drum, and it exhausts burnt gases from the arc through the exhaust vent.
Fresh air enters the drum at five intake vents.
This motor causes the searchlight to rotate in azimuth and is controlled by the azimuth distant electric control handwheels at. the control station. (For the M-VI light only: A control switch for this motor is mounted under main power receptacles.)
When clutch lever is in the out position, the shaft of the azimuth control motor is disconnected. When the clutch lever is in, the azimuth control motor shaft is connected to the searchlight ring gear and can turn the light in azimuth.
To furnish illumination so azimuth scale may be set to correct azimuth when orienting.
All cables are connected to the junction box, and wiring goes out of the junction box to connect the proper circuit.
Made of sheet duralumin, it is bolted to the rear drum, and supports the front door.
This glass protects the arc from wind and rain. The 12-segment construction makes it shockproof.
There are two sliding panels, one on each side of the front drum, to permit access to the interior of the drum for maintenance and recarboning.
To observe the condition and position of the arc.
Encased in a housing, this resistor is in the arc circuit to give the arc stability so it will not sputter. Never adjust this resistor except under direction of an electrician sergeant or an officer.
Permits access into the base to inspect brushes and slip rings which form a part of various circuits, including the main arc circuit.
These are provided so that the error in pointing the searchlight in elevation may be determined. The sights are graduated in mils.
Mechanism for supporting and feeding the carbons.
To give illumination inside the drum when recarboning the lamp at night.
For steering the searchlight.
To lock the searchlight drum in its traveling position.
These are provided so that the error in pointing the searchlight at the target in azimuth may be determined.
For use in orienting the searchlight with sound locator. (On earlier models than the M1941, the orienting sights are mounted on the right side of the drum.
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Figure 3.—Sperry M1941 antiaircraft searchlight (rear quarter view).
Part
Purpose or use
41. Elevation control motor.
45. Arc view peep sight________
60. Ballast resistor___________
67. Azimuth daylight sights..
68. Lamp control mechanism box.
70. Recarboning lamp switch.
This motor causes the searchlight to elevate or depress and is controlled by the elevation distant electric control handwheels at the control station. (For the M-VI light only: A control switch for this motor is mounted on the right trunnion arm.)
To observe the condition and position of the arc.
Encased in a housing, this resistor is in the arc circuit to give the arc stability so it will not sputter. Never adjust this resistor except under direction of an electrician sergeant or an officer.
These are provided so that the error in pointing the searchlight in azimuth may be determined.
This box houses the mechanism which automatically feeds the carbons so that the arc operates at a voltage of 78 volts and a current of 150 amperes.
Turns on the recarboning lamp. The scale and meter light switch must be on also, except on the M-VI light.
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70
. 7i
72
45
74
75
41
96 7§;
67
82
S3
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88
89
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GUNNERS' INSTRUCTION, AA SEARCHLIGHT BATTERIES 8
Part
71. Elevation scale lamp___
72. Elevation scale________
73. Elevation gear sector__
74. Meter box______________
75. Hand controller socket_
76. Arc switch box_________
77. Extension lamp receptacle.
78. Scale and meter light switch.
79. Azimuth lock___________
80. Azimuth scale__________
81. Azimuth data receiver housing. (Not part of M1934 and M-VI lights. M-VI light has a transmitter instead of a receiver at this location.)
82. Ventilating motor housing.
83. Transportation lock bar lug.
84. Power cable receptacles ..
85. Control station cable receptacle.
86. Sound locator cable receptacle. (Not part of the M-VI and M1934 lights since this cable goes to comparator directly on these models. The M-VI light has a white receptacle and a green receptacle at this location.)
87. Signal buzzer. (Not part of the M-VI or M1934 lights.)
88. Dynamotor (behind wheel). (For the M-VI light it is located at the power plant. For the M1934 unit it is located at the control station.)
89. Dynamotor pilot light__
90. Leveling jacks_________
196. Recarboning safety switch. (Found only on
the M1941 light.)
Purpose or use
To illuminate the elevation scale when orienting.
It is used for orienting and pointing the light in elevation.
The elevation control motor and the elevation extended hand control are geared to this gear sector so that the light may be elevated or depressed.
It contains an azimuth zero reader, an elevation zero reader, an ammeter to check the arc current at 150 amperes, and a voltmeter to check the arc voltage at 78 volts. (For the M1937 light only: The elevation zero reader is mounted near the left trunnion on its receiver, the azimuth zero reader on the base of the light near its receiver.) (For the M-VI and M1934 lights only: There are no zero readers on these lights.)
The extended hand controller fits into this socket.
This box houses the arc switch.
A trouble lamp extension cord is connected to this receptacle.
Lights lamps so that the meter box instruments can be seen, and also turns on the azimuth and elevation scale lamps.
Locks searchlight in azimuth traveling position.
For orienting the searchlight in azimuth.
It houses the azimuth data receiver which is connected electrically by cable to the sound locator azimuth data transmitter. The receiver causes the azimuth zero readers (one at the searchlight and one at the control station) to indicate azimuth data. (For the M-VI light only: The transmitter sends data to the comparator giving the light position.)
Houses ventilating motor and fan.
The transportation bar is locked to this lug so that the drum can be locked in its traveling position.
Painted yellow. The yellow positive and negative power cables are connected here.
Painted red. The red cable from the control station is connected here.
Painted blue. The blue cable from the sound locator connects to this receptacle. (For the M-VI light only: The white cable for sending searchlight position data to the comparator connects to the white receptacle. The green cable for delivering 110 volts alternating current for the a-c data transmission system connects the green receptacle to the power unit.)
The buzzer switch-button at the control station is closed when the searchlight is to be put IN ACTION.
This is a motor generator. The motor operates at line voltage, driving the generator which generates 110-volt alternating current to operate the data transmission system.
A red light indicates that there is a-c power for the data transmission system. For leveling the searchlight. Two levels are provided on the base of the searchlight for this purpose.
Switch must be thrown to recarboning position before entering drum, otherwise a person may be killed.
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14
Figure 4.—Lamp and lamp control mechanism. Sperry M1941 searchlight.
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16
25
47
13
33 23
45 42 46
40
30 21
8
3
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Part
1. Negative carbon__________
3. Negative control rod_____
8. Negative hand feed knob .
9. Negative feed centralizer lever.
13. Positive carbon_________
16. Positive control rod______
21. Positive hand feed handwheel.
23. Positive feed rate adjustment screw.
25. Thermostat______'_____
26. Thermostat lens_______
30. Feed motor------------
33. Arc length adjustment screw.
40. Elevation control clutch lever.
41. Elevation control motor..
42. Focusing knob (behind meter box).
43. Thermostat adjusting screw.
45. Peep sight____________
46. Ground glass finder____
47. Focusing rod__________
Purpose or use
This carbon, plus the positive carbon, allows the arc to function by having direct current pass through it.
This rod rotates so as to feed the negative carbon forward or backward. Turning this knob by hand turns the negative control rod and feeds the negative carbon. Keep voltmeter voltage at 78 volts by turning this knob when using hand feed.
When this lever is moved to its auto position, the negative carbon feeds automatically. When moved to hand position, the negative carbon must be fed by hand. (See part 8 above.)
When the arc is operating, the positive carbon burns, causing incandescent gas to form a positive crater. From this crater comes the brilliant light for the beam.
This rod rotates counterclockwise so that the positive carbon may be fed forward and rotated to cause the positive crater to burn evenly.
Rotating this handwheel counterclockwise rotates the positive control rod so as to feed and rotate the positive carbon.
Adjust this screw so that the normal rate of feed (one click) is slightly less than the rate of burning of the positive carbon. This normal rate of feed allows the positive carbon to burn back slowly so that the thermostat may act to keep the positive crater at the focal point of the metal mirror.
When the positive carbon burns back, the positive crater moves away from the focal point of the mirror. This causes rays of light to be focused on a bimetallic strip which is warped by the heat from the light rays. When the bimetallic strip warps it closes a circuit which automatically causes the positive carbon to feed forward to the focal point of the mirror.
This lens focuses rays of light so as to cause the thermostat to operate.
This motor activates the feed mechanism so that the positive and negative carbons may be fed automatically.
In automatic operation, this screw is adjusted so that the arc voltage is 78 volts as read on the voltmeter.
With this clutch in the D. E. C. position, the searchlight is elevated or depressed by distant electric control. With the clutch in the hand position, the extended hand controller is used to elevate or depress the searchlight.
See figure 3.
Turning this knob moves the lamp unit back and forth on the arc lamp column. By this means the positive crater is moved to the focal point of the mirror.
This screw adjusts the distance between the contacts of the thermostat bimetallic switch.
To observe the condition and position of the arc.
This is used to check accurately the position of the positive crater. The end of the positive carbon should terminate at the black or focal line. Never allow the positive carbon to burn back beyond the red danger line.
This rod rotates when the focusing knob is turned, and moves the lamp unit so that the positive crater is at the focal point of the mirror.
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COAST ARTILLERY CORPS
I NEGATIVE CARBON
' ■'r-iWOSTAT I.FN5 '
4 h-GA-IVE COKTROI POD ’
5 THERMOSTAT
t POE -FF3 RAI _ ADJUSTINGKNOB
■ NC6AHVE HAND FEED KNOB
2 NEG. FEED CENTRALIZER KNOB
13 ARC _ENGIH CONTROL CO i -
IS P&S ' :VL CARBON
I? POSITIVE CONTROL ROD
18 PQS. FEED CONTROL ELECTRO"MAGNET
22 POSITIVE HAND FEED KNOB
23 RECIPROCATING FEED MEMBER
24 PEED MOTOR
26 ARC LENGTH ADJUSTING SPRING
27 ARC LENGTH ADJUSTING SCREW
4R F. FVAT.ON CONTROL CLUTCH LEVER
4'-> LLtV'.fION «0NW'_ MOTOR
91 FOCUSING KNOB (SEHINS:METER BOX} $»-• iHERMCS-AI ADJUSTING SCREW
235 PLUG
264 PEEP SIGHT
1265 GROUND GLASS FINDER
2>'7 FOCUSING ROD
Note. The nomenclature of the M-VI, M1937, M1939, and M1940 Sperry lights is the same as that of the M1934 light.
Figure 5.—Lamp and lamp control mechanism, Sperry M1934 searchlight.
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TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 8
Part
1. Negative carbon________
3. Thermostat lens--------
4. Negative control rod___
5. Thermostat_____________
6; Positive feed rate adjusting knob______________________
11. Negative hand feed knob
12. Negative feed centralizer knob__________________________
13. Arc length control coil___
15. Positive carbon___________
17. Positive control rod____
18. Positive feed control electromagnet.
22. Positive hand feed knob-
23. Reciprocating feed member.
24. Feed motor______________
26. Arc length adjusting
spring.
27. Arc length adjusting
screw.
48. Elevation control clutch lever.
49. Elevation control motor-.
91. Focusing knob (behind meter box).
94. Thermostat adjusting screw.
235. Plug____________________
Purpose or use
This carbon, plus the positive carbon, allows the arc to function by having di'iect current pass through it.
This lens focuses rays of light on the thermostat bimetallic strip.
This rod rotates so as to feed the negative carbon forward or backward.
When the positive carbon burns back, the positive crater moves away from the focal point of the mirror. This causes rays of light to be focused on a bimetallic strip which is warped by the heat from the light rays. When the bimetallic strip warps, it closes a circuit which automatically causes the positive carbon to feed forward to the focal point of the mirror.
Adjust this knob so that the normal rate of feed (one click) is slightly less than the rate of burning of the positive carbon. This normal rate of feed allows the positive carbon to burn back slowly so that the thermostat may act to keep the positive crater at the focal point of the metal mirror.
Turning this knob by hand turns the negative control rod and feeds the negative carbon. Keep voltmeter voltage at 78 volts by turning this knob when using hand feed.
When this knob is moved to its auto position, the negative carbon feeds automatically. When moved to hand position, the negative carbon must be fed by hand.
This coil acts as a magnet and positions an armature which causes the negative carbon to feed so as to keep the arc length constant.
When the arc is operating, the positive carbon burns, causing incandescent gas to form a positive crater. From this crater comes the brilliant light for the beam.
This rod rotates counterclockwise so that the positive carbon may be fed forward and rotated to cause the positive crater to burn evenly.
This magnet is energized when the thermostat operates. It pulls up a guard so that the positive carbon may be fed forward faster.
Rotating this knob counterclockwise rotates the positive control rod so as to feed and rotate the positive carbon.
The part is moved back and forth by the feed motor and causes the positive and negative carbons to be fed.
This motor is the source of power for operating the feed mechanism.
This holds the armature in its correct position against the pull of the arc length control coil.
It adjusts the arc length adjusting spring so as to keep the arc voltage at 78 volts as read on voltmeter.
With this clutch in the D. E. C. position, the searchlight is elevated or depressed by distant electric control. With the clutch in the hand position, the extended hand controller is used to elevate or depress the searchlight.
Causes light to be elevated or depressed. It is controlled by the elevation operator at the control station.
Turning this knob moves the lamp unit back and forth on the arc lamp column. By this means the positive crater is moved to the focal point of the mirror.
This screw adjusts the distance between the contacts of the thermostat bimetallic switch.
Removal of this plug provides access to the feed motor shaft.
422589°—42---2
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9. Control stations.—Q. Why is a control station necessary? A. To obtain the best “contrast” the operator must be at least 50 feet away from the searchlight beam. At this distance an electrical remote control system must be used to point the. searchlight in azimuth and elevation. The control station is a part of this remote control system, and from this station the searchlight may be pointed in azimuth and elevation.
Q. What is meant by contrast? A. Contrast means the difference between the amount of light reflected from the target and the amount of light reflected from the illuminated sky background. The better the contrast the better the target can be seen in the beam.
Q. In addition to being able to control the searchlight from a remote point, what other function must the control station perform? A. It must give an indication of sound locator data so that the search-
Note.—The nomenclature of the M1937, M1939, and M1940 Sperry control stations is the same as the M1941 control station.
Figure 6.—Sperry M1941 control station (binocular mount in position).
1’8
■ 134
135
• 136
’ 138
140
146
• 145
" 143
■ 150
' 15!
' 154
‘ 157
137
142
141
139
147
149
14 4 ■
148 ■
153 ■
152 ■
155
156
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 9 light may be pointed correctly. Also, the M1934 and later control stations have a means for searching 5° around sound locator data.
Q. How is searching accomplished on the Sperry control stations? A. (1) For the M1939, M1940, and M1941 control stations only: Each zero reader has three graduations on its face: a center index and a graduation on either side of the index. Using the zero reader handwheel to move the pointer slowly between the outer graduations will cause the searchlight to search 5° around sound locator data.
Part
134. Open sight_____________
135. Binocular mount________
136. Binocular mount counterweights.
137. Binocular elevation zero marker.
138. Binocular azimuth zero marker.
139. Binocular mount adjustment handles.
140. Binocular height adjusting knob.
141. Binocular mount azimuth adjustment.
142. Binocular mount clutch adjustment.
143. Observer’s elevation handwheel.
144. Observer’s azimuth handwheel.
145. Elevation drive slip clutch.
146. Azimuth drive slip clutch.
147. Azimuth zero reader--
148. Azimuth zero reader handwheel.
149. Signal buzzer push button.
150. Zero reader light switch.
151. D-c switch____________
152. Alinement lug_________
153. Carrying handles-----
154. Handhole cover plate--
155. Tripod..______________
156. Fifteen-point receptacle-
157. Leveling jack_________
Purpose, or use
For getting approximately on a target and for orienting the control station Supports binoculars. This mount is geared to the elevation zero reader handwheel so that binoculars may be pointed in elevation according to sound locator data. It moves in azimuth as the control unit moves.
To balance the binoculars.
To establish zero elevation when orienting the control station.
To establish the correct azimuth when orienting the control station.
By grasping these handles the binocular mount can be moved in azimuth and elevation. They are used especially to put the binocular line of sight on the searchlight beam in case the beam is not seen in the binoculars.
This knob allows adjustment of the binocular mount for individual height.
Tightening up on this adjusting nut tightens a spring friction disk so binocular mount does not move too easily in azimuth.
This adjusting screw must be adjusted so that binbcular mount does not move too easily in elevation.
The observer uses this handwheel to track in elevation after the target is flicked.
The observer uses this handwheel to track in azimuth after the target is flicked.
This clutch protects the elevation drive mechanism.
This clutch protects the azimuth drive mechanism.
This is a voltmeter whose pointer moves away from its center (zero) position as new sound locator azimuth data is received.
This handwheel rotates the control station and operates the azimuth D. E. C., which traverses the searchlight. This causes the pointer of the azimuth zero reader to move to its zero position when the searchlight is pointed according to sound locator azimuth data.
This is used to signal the searchlight to go in action or out of action.
The switch when turned on lights the zero reader dials.
The switch must be turned on before the D. E. C. can be used.
This lug fits in a notch machined in the control unit. The lug and notch must be lined up when putting control unit on tripod.
Self-explanatory.
Access may be had to the slip rings which electrically connect red cable to interior of control station.
Supports control unit.
Red cable plug from searchlight fits into this receptacle.
Adjustment of these jacks permits leveling of the control station by means of spirit levels.
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(2) For the M1937 control station only: Pushing in the search control knob (located to the right of the azimuth zero reader) causes an electric motor to drive an oscillating mechanism, which causes an automatic oscillation in elevation of 5° around sound locator data. Rotating the search control knob slowly offsets the azimuth zero reader pointer which, when brought back to its center position, causes a 5° search in azimuth around sound locator data.
(3) For the M1934 control station only: An automatic spiral searching device, which causes a search in both azimuth and elevation of 5° around sound locator data, is controlled by a handwheel placed directly under the binocular mount. When the handwheel is rotated slowly the searchlight searches 5° around sound locator data.
Q. Name and give the functions of the various parts of the control station with which your organization is equipped. A. See figures 6. 7, 8, and 9.
141
140
158
159
160
161
157
135
>85
144
143
151
154
(56 ■
Note.—The nomenclature of the M1937, M1939, and M194o control stations is the same as the M1941 control station.
Figure 7.—Sperry M1941 control station (binocular mount folded down).
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TM 4-330
GUNNERS1’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 9
Part
135. Binocular mount. _ ...
140. Binocular height adjusting knob.
141. Binocular mount azimuth slip clutch.
143. Observer’s elevation handwheel.
144. Observer’s azimuth handwheel.
151. D-c switch___________
154. Handhole cover plate__
156. Fifteen-point cable receptacle.
157. Leveling jacks--------
158. Elevation zero-reader_
159. Elevation zero-reader handwheel.
160. Spirit levels_________
161. Clamp knob------------
185. Binocular mount locking pin.
Purpose or use
See figure 6.
See figure 6.
See figure 6.
See figure 6.
See figure 6.
See figure 6.
See figure 6.
See figure 6.
See figure 6.
This is a voltmeter whose pointer moves away from its center (zero) position as new sound locator elevation data is received.
This handwheel elevates the binocular mount and operates the elevation D. E. C., which elevates the searchlight. This causes the pointer of the elevation zero reader to move to its zero position when the searchlight is pointed according to sound locator elevation data.
These spirit levels are used to level the control station.
Two knobs, on opposite sides of the control unit, lock the control unit to the tripod.
This locks the binocular mount in its operating position so mount will move in elevation.
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Figure 8.—Sperry M1934 control station.
22
3i 6
3i?
21? ■
221
390
,220
(48
x2l8
? 18$
- 222
161
381

320'
219

-34 2
315
314
- 147
. U*- 83
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 9
Part
Purpose or use
83. Leveling jacks________
147. Tripod_______________
148. Control unit_________
161. Elevation handwheel clutch knob.
188. Searching handwheel__
211. Azimuth handwheel clutch knob.
217. Sound locator azimuth dial synchronizing knob.
218. Sound locator elevation dial synchronizing knob.
219. Handhole cover plates. __
220. Binocular height adjusting knob.
221. Azimuth drive friction clutch adjustment screw.
222. Elevation drive friction clutch.
314. Alinement slot_______
315. Alinement lug________
316. Open sight___________
317. Binocular____________
320. A-c switch___________
342. D-c switch___________
390. Observer’s azimuth handwheel.
391. Observer’s elevation handwheel.
Adjustment of these jacks permits leveling of the control station by means of spirit levels.
Supports control unit.
This unit houses the D. E. C. and comparator mechanism.
With clutch in, the control station may be oriented and synchronized.
Rotation of this hand wheel allows a search of 5° around sound locator data.
This knob is pushed in when orienting and synchronizing.
This knob is used to synchronize the azimuth receiver with the sound locator azimuth transmitter.
This knob is used to synchronize the elevation receiver with the sound locator elevation transmitter.
Removal of these three plates provides access to the slip rings and brushes.
To adjust the binocular to any desired height.
Adjust this screw until a position is obtained at which the azimuth handwheel will slip if jerked.
Adjust this screw until a position is obtained at which the elevation handwheel will slip if jerked.
This slot must engage a lug on the tripod when setting up the control station.
See remark above.
Por approximately orienting the control station.
For searching the searchlight beam.
This switch supplies a-c power for the data transmission system.
This switch supplies d-c power for the distant electric control.
The observer can control the searchlight in azimuth by means of this handwheel. To the shaft of this handwheel on the opposite side of the control unit is the azimuth follow-the-pointer handwheel.
The observer can control the searchlight in elevation by means of this handwheel. To the shaft of this handwheel, on the opposite side of the control unit, is attached the elevation follow-the-pointer handwheel.
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Figure 9.—Sperry M—VI control station.
13
12

IO
9
2
3
4
5
6
8
7
I
24
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 9-10
Part
1. Azimuth handwheel________
2. Searchlight controller___
3. Elevation handwheel____. _
4. Cable from tripod to controller.
5. Azimuth training gear____
6. Tripod_____a_____________
7. A-c comparator___________
8. Synchronizing knob. ...
9. Cables from tripod to comparator.
10. Slip ring cover__________
11. Receptacle for controller cable.
12. Receptacle for sound locator cable.
13. Receptacle for searchlight cable.
Purpose or use
This handwheel controls the searchlight in azimuth.
This houses the D. E. C. mechanism which causes the searchlight to be controlled remotely in azimuth and elevation from the control station.
This handwheel controls the searchlight in elevation.
The wire conductors for the electric circuits of the D. E. C. are contained in this cable.
Movement of the azimuth handwheel causes the comparator and controller to rotate in azimuth about the tripod by means of this gear.
The tripod supports the controller and comparator.
This houses four a-c synchronous receivers. Two are connected through the blue cable to the sound locator, one for azimuth, the other for elevation. The other two are connected by the white cable to the searchlight, one for azimuth, the other for elevation. The azimuth operator causes the two azimuth pointers to be matched, while the elevation operator matches the two elevation pointers.
For synchronizing the receivers with their respective transmitters. Connects the four receivers to the white and blue cables.
Removing this cover provides access to the slip rings and brushes.
Painted red. This cable connects the controller to the searchlight training motors.
Painted blue. This cable connects the comparator sound locator data receivers to their respective transmitters at the sound locator.
Painted white. This cable connects the comparator searchlight receivers to their respective transmitters at the searchlight.
10. Power plants.—Q. What difference is there between the 1941 Sperry power plant and previous Sperry power plants? A. There is very little difference between the Sperry 1941 power plant and the previous models. The rated speed of the engine varies, but in general, all models back to and including the portable M1934 power plant are very similar.
Q. What is the rated engine horsepower of the 1941 Sperry power plant? A. It is rated at 42 hp at 1.100 rpm.
Q. What is the generator rating of the M1941 Sperry power plant? A. The generator is rated as follows:
Volts Amperes Rpm Kilowatts
100 162 1,100 16.2
Q. Is the power plant engine similar to an ordinary automobile engine? A. Yes. It has a self-starter, battery, battery charging generator, water-cooling system, ignition, choke, and other features of an ordinary automobile engine.
Q. Point out the various parts, by name, of the power plant with which your organization is equipped. A. Refer to figures 10 and 11 for the M1941 Sperry power plant.
Note.—For the mobile M-VI, mobile M1934, portable M1934, M1937, M1939. and Ml940 power units, refer to the Operator’s Manual furnished with these units, using examination questions and nomenclature corresponding to those used in this manual.
25
TM 4-330
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COAST ARTILLERY CORPS
26
Figure 10.—Sperry M1941 power plant (left side).
I 9 4 2 3
10 5 7
5
8
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 10
Part Purpose or use
1. Control panel .. Contains all the necessary indicating instruments and equipment for controlling and operating the unit.
2. Power receptacles Provides a convenient means of attaching and removing the two power cables that transmit the electrical power from the power plant to the searchlight. One receptacle is for the positive cable, the other receptacle for the negative cable.
3. Fuel tank 4. Tail lamp 5. Control panel door bracket 6. Tow bar 7. Power generator Gasoline supply for the engine. Capacity is 27J4 gallons. Same purpose as tail lamp on automobile. Holds the control panel door in a horizontal position. Used for towing and steering. A d-c compound wound generator which furnishes electrical power to operate the searchlight section.
8. Fan Used for cooling the power plant. It is driven by a direct current % bp motor.
9. Tail lamp switch 10. Oil filter Turns tail lamp on or off. Filters the oil in the engine.
27
COAST ARTILLERY CORPS
TM 4-330
10
28
Figure 11. Sperry M1941 power plant (right side).
J2 . II 20
/
14 19
13 s
16 x
15 x
17
\
18 x
TM 4-330
GUNNERS’’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 10-11
Part Purpose or use
11. Radiator Cools the liquid in the engine cooling system.
12. Air filter Filters the air going into the carburetor.
13. Fan motor A % hp, d-c motor, having two speeds: winter, 500 rpm; summer. 675 rpm.
14. Battery , Furnishes 6 volts for the engine ignition system and 6-volt lights on the control panel and tail light.
15. Tool box Storage place for tools.
16. Spare wheel and tire .. , Self-explanatory.
17. Fuel tank filler pipe Self-explanatory.
18. Brake lever Self-explanatory.
19. Safety chain brake cable Operates, in case the safety chain breaks, to apply the brakes on the power plant.
20. Exhaust Self-explanatory.
Section II
GENERAL ELECTRIC SEARCHLIGHT EQUIPMENT
Paragraph
Searchlights___________________________________________________ 11
Control stations_____________<.-------------------------------- 12
Power plants___________________________________________________ 13
11. Searchlights.—Q. In learning the names of the various parts, what should you keep in mind? A. You should strive to learn not only the names of the parts, but should learn the purpose or use of each part.
Q. What is the operating voltage and current of the arc? A. It operates at 78 volts with a current of 150 amperes flowing through the arc.
Q. What is the maximum range of the searchlight? A. This depends on atmospheric conditions. An average value of 10,000 yards is given as an approximate maximum range under good conditions.
Q. What shape or type is the mirror of the searchlight? A. It is a metal parabolic mirror. This means that if a source of light is emitted from the focal point of the mirror, the rays of light are reflected in parallel rays of light.
Q. What is the beam candlepower ? (An ordinary candle is rated at 1 candlepower.) A. It is rated at 800 million candlepower.
Q. What causes such a great amount of light in the beam? A. This is caused by the burning of gases in the positive carbon crater.
Q. In how many ways may the carbons be fed? A. Three: automatically, semiautomatically, or by hand.
Q. How can you tell the positive carbon from the negative carbon? A. The positive carbon is longer and thicker than the negative carbon. When issued the positive carbon is 22 inches long and 0.633 inch in diameter; the negative carbon is 12 inches long and 0.434 inch in diameter.
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COAST ARTILLERY CORPS
Q. Which carbon burns out first? A. The positive carbon. For this reason the arc must be watched carefully so that the positive nose cap is not melted.
Q. What piece of equipment is provided for hand control of the light in azimuth and elevation? A. An extended hand controller is provided for this purpose.
Q. Point out the various parts of the M1940 Genera] Electric searchlight. A. See figures 12, 13,14, and 15.
Figure 12.-—General Electric M1940 searchlight (front quarter view).
30
105
188
103,
107
147
102,
104
I47X
153
148
t 10
157
2Oi
200
204 205.
108
212
156-
11 I
1 12
134
144
133
1 14
I SC
128
127
154
155/
151
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 11
Part
Purpose or use
102. Arc viewing window______
103. Ventilating fan motor housing.
104. Arc image screen________
105. Azimuth daylight sights.
107. Lamp control mechanism box.
109. Elevation brake handle..
110. Extended hand control bar socket.
111. Recarboning lamp switch.
112. Scale lamp switch___
114. Azimuth scale lamp__
127. Azimuth clutch handle..
128. Dynamotor switch____
130. Elevation stowing rod...
133. Towing bar____________
134. Junction box__________
144. Ballast resistor______
147. Focusing knob_________
148. Extended hand control bar clamp.
149. Elevation scale lamp__
151. Drum access door______
153. Elevation control box_
154. Azimuth control box___
155. Azimuth scale_________
156. Arc switch handle_____
157. Counterweight_________
168. Glass door____________
200. Azimuth zero reader___
201. Elevation zero reader__
204. Arc ammeter_________
205. Arc voltmeter_______
212. Dynamotor a-c indicating lamp.
To observe the position and condition of the arc.
This houses the ventilating fan which exhausts the burned gases from the drum interior.
This is used to check accurately the position of the positive crater. The end of the positive carbon should terminate at the black focal line. Never allow the positive carbon to burn back beyond the red danger line.
For use in training. Platoon commander may check in azimuth while a target is being tracked, thus observing any error.
Within this box are located the various mechanisms for feeding the positive and negative carbons.
For locking the searchlight at any desired elevation.
The extended hand control bar fits in this socket so light may be moved by hand in elevation and azimuth.
Light is turned on inside the drum during recarboning.
This switch turns on meter, elevation scale, and azimuth scale lamps.
To illuminate azimuth scale.
This disconnects the azimuth D. E. C. training motor when traversing by hand.
This turns on the dynamotor which converts direct current into alternating current for use in the data transmission system and for the D. E. C. system.
The searchlight drum is elevated and locked in this position by means of the stowing rod when the light is put in traveling position.
For steering the light and for towing by hand for short distances.
All cables are connected to the junction box. from which place connections are made to the proper circuits.
This resistor is in the arc circuit. Never change this connection except under the direct supervision of an electrical sergeant or an officer.
By turning this knob the lamp may be moved so that positive crater is at the focal point of mirror.
This clamps the extended hand control bar in the socket.
For illuminating the elevation scale.
For entering drum for recarboning, or other purpose.
Within this box is the D. E. C. elevation training motor and its auxiliary equipment.
Within this box is the D. E. C. azimuth training motor and its auxiliary equipment.
This scale is used when orienting the searchlight. It may be slipped around for proper setting.
This switch when closed allows the are to form and a current to flow through it.
This helps to balance the searchlight on its trunnions.
This glass protects the arc from wind and rain. The 12-segment construction makes it shockproof.
This is a voltmeter which has a pointer at the center of its scale. When new sound locator azimuth data are received this pointer moves away from its center (or zero) position.
This is a voltmeter with a pointer at the center (or zero) of its scale. When new sound locator elevation data are received the pointer moves away from its center (or zero) position.
This ammeter indicates the amount of current flowing through the arc. It should read 150 amperes when the arc is operating properly.
The voltmeter indicates the voltage drop across the arc. It should read 78 volts when the arc is functioning properly.
A red lamp glows when the dynamotor is operating.
31
TM 4-330
11
COAST ARTILLERY CORPS
Figure 13.—General Electric M1940 searchlight (rear quarter view).
»2
too
.106
102
124
117
n«
145

119
108
156
131
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 11
Part Purpose or use
100. Drum 102. Arc viewing window 106. Elevation daylight sights. 108. Elevation clutch handle.. 116. Levels.. 117. Spindle cover 119. Azimuth correction knob. 124. Elevation data receiver cover. 129. Azimuth stowing lock. 131. Leveling jacks 145. Dynamotor 156. Arc switch handle. ... The drum contains the metal mirror and supports the lamp, lamp feed mechanism, and the ventilating system. To observe the position and condition of the arc. For use in training. Platoon commander can check in elevation while a target is being tracked, thus observing any error. When this handle is in the hand control position the searchlight may be elevated by hand. To level the searchlight. For access to the spindle and azimuth data receiver. For use when synchronizing the azimuth zero reader system. This cover must be taken off to synchronize the elevation zero reader system. When putting the searchlight in traveling position this locks the searchlight in azimuth. For leveling the searchlight. Converts direct current to alternating current which is used by the data transmission system and the D. E. C. system. Closing this switch permits the arc to start.
422589°—42---3
33
TM 4—330
11
COAST ARTILLERY CORPS
Figure 14.- -General Electric M1940 searchlight (right upper view).
34
31
33
30
102
32

i*t
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 11
Part
Purpose or use
30. Negative carbon manual drive crank.
31. Positive carbon feed button.
32. Positive carbon feed rate adjustment knob.
33. Positive carbon manual drive crank.
102. Arc viewing window____
104. Arc image screen______
147. Focusing knob_________
158. Arc image adjusting screws.
By pushing this crank in, the negative carbon may be fed by hand instead of automatically.
Push button in to feed positive carbon faster. In hand operation it is worked in conjunction with part 33.
Turning this knob clockwise causes the positive carbon to feed faster.
Push in crank and turn in clockwise direction to rotate positive carbon. In hand feed it is worked in conjunction with part 31.
To observe the condition and position of the arc.
This is used to check accurately the position of the positive crater. The end of the positive carbon should terminate at the black focal line. Never allow the positive carbon to burn back beyond the red danger line.
By turning this knob the lamp assembly is moved so that the positive crater is placed at the focal point of the mirror.
These are for making a correct adjustment of the positive carbon on the image screen by the searchlight commander.
35
TM 4-330
11
COAST ARTILLERY CORPS
Part
Purpose or use
1. Obturator______________
2. Thermostat mirror______
3. Thermostat_____________
4. Positive carbon protrusion adjusting nut.
5. Negative head mounting bolts.
I
This is a bronze casting to protect the positive head from excessive heat. It also prevents stray light.
This mirror reflects rays of light from the positive crater onto the thermostat.
When the positive carbon burns back too far, rays of light heat up the thermostat bimetallic strip which closes a circuit. This causes the positive carbon to feed forward to its proper position.
This adjustment positions the thermostat mirror which, through the thermostat, keeps the positive carbon at its proper position, 54 inch from positive nose.
Holds negative head to lamp base.
6. Negative carbon________
7. Negative nose__________
8. Movable drive roller bracket.
9. Negative carbon drive pressure spring.
10. Negative carbon drive roller clamp.
11. Negative carbon brush pressure adjusting nut.
12. Negative carbon brush pressure spring.
13. Adjustable drive roller bracket.
14. Negative brush_________
15. Positive carbon feed roller clamp.
16. Positive carbon_______
49. Positive head mounting j bolt.
This carbon, plus the positive carbon, allows the arc to function by having direct current pass through it.
Bronze casting for holding negative carbon.
On this bracket are mounted the upper negative feed rollers.
This spring causes the negative feed rollers to make good contact with the negative carbon.
Pushing this clamp to the left lifts the movable drive roller bracket so that a new negative carbon may be inserted.
Screwing the adjusting nut farther up causes more pressure to be applied by negative brush 14 on negative carbon 6.
This spring exerts the force which causes a pressure of the negative brush on the negative carbon.
On this adjustable bracket are mounted the lower negative feed rollers.
This brush makes a good contact with the negative carbon so current may flow through it more easily.
This clamp is used when renewing the positive carbon. It separates the positive feed rollers.
When the arc is operating, the positive carbon burns, causing incandescent gas to form a positive crater. From this crater comes the brilliant light for the beam.
This holds the positive head to the lamp base.
36
16
15

2
6
8
9
3
49 4,
5
14 13
12
II
10
Figure 15.—General Electric M1940 lamp.
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GUNNERS-' INSTRUCTION, AA SEARCHLIGHT BATTERIES 12
12. Control stations.—Q. Why is a control station necessary ?
A. To obtain the .best “contrast” the observer must be at least 50 feet away from the searchlight beam. At this distance an electrical remote control system must be used to point the searchlight in azimuth and elevation. The control station is a part of this remote control system, and from this station the searchlight may be pointed in azimuth and elevation.
Q. What is meant by contrast? A. Contrast means the difference between the amount of light reflected from the target and the amount of light reflected from the illuminated sky background. The better the contrast, the better the target can be seen in the beam.
Q. In addition to being able to control the searchlight from a remote point, what other function must the control station perform?
A. It must give an indication of sound locator data so that the searchlight may be pointed correctly. Also, the General Electric control station has a means for searching 5° around sound locator data.
Q. Name and give the functions of the various parts of the 1940 General Electric control station. A. See figures 16 and 17.
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Figure 16.—General Electric M1940 control station (right side view).
38
405
64
446
445
434

458
457
-447
"Ttf ■
jg r® jl
**kJ0L

463
435
AO
411
465

461
-463
'460
418
M)
404
401

TM 4-330
GUNNERS’’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 12
Part
Purpose or use
400. Tripod_______________
401. Leveling jack_________
404. Tripod leg braces_____
405. Binocular mount_____
411. Elevation zero indicator
417. Observer’s elevation handwheel.
418. Elevation zero reader’s handwheel.
Controller is supported by this tripod.
By adjusting the three jacks the control station may be leveled.
To give rigidity to the tripod.
Supports binoculars. This mount is geared to the elevation zero reader handwheel so that binoculars may be pointed in elevation according to sound locator data. It moves-in azimuth as the controller moves.
This is a voltmeter whose pointer moves away from its center (zero) position as new sound locator elevation data is received.
The observer uses this handwheel to track in elevation after the target is flicked.
This handwheel elevates the binocular mount and operates the elevation D. E. C., which elevates the searchlight. This causes the pointer of the elevation zero reader to move to its zero position when the searchlight is pointed according to sound locator elevation data.
This clamp must be adjusted so that the elevation clutch does not allow the binocular mount to move too easily in elevation.
The observer uses this handwheel to track in azimuth when the target is flicked.
This column is a support for the binocular mount.
Self-explanatory.
This is used when orienting the control station and for quickly getting on an illuminated target.
This allows adjustment of the height of the binocular for each individual.
| When binocular mount is lowered in column, it is locked by pushing in this lock clamp and turning clockwise.
i By grasping these handles the binocular mount can be moved in azimuth and elevation. They are used especially to put the binocular line of sight on the searchlight beam in case the beam is not seen in the binoculars.
j To signal searchlight to go in action or out of action.
This nut is adjusted so that the binocular mount does not move too easily in azimuth.
For use in orienting the control station in azimuth.
For use in orienting the control station in elevation.
434. Binocular linkage clamp.
435. Observer’s azimuth handwheel.
444. Binocular mount column.
445. Binoculars____________
446. Open sight.___________
447. Binocular height adjusting crank.
453. Binocular column lock clamp.
454. Binocular positioning handles.
455. Signal switch________
457. Binocular column azimuthfriction adjusting nut.
458. Azimuth reference mark.
459. Horizontal reference mark.
460. Controller box. .____
461. Elevation zero-reader adjustment plug.
463. Level_________________
464. Linkage pin.......
465. Column socket cover__
The controller box houses all the mechanisms and supports the binocular mount.
Loosen the plug and, with a small screw driver, turn voltmeter pointer adjusting screw until pointer is zeroed.
To be used when leveling the control station.
This pin must be in place so that the binocular mount operates properly.
When binocular mount is disassembled, this cover is screwed over the opening in the controller box.
I
39
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Figure 17.—General Electric M1940 control station (rear view).
40
j.4,6
-445
434

453
463
418
435
417
420
456 ~~JI
Wu
401
436
412
443
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 12-13
Part Purpose or use
401. Leveling jack See figure 16.
412. Scale lamp switch — To provide illumination for the zero readers.
417. Observer’s elevation handwheel. See figure 16.
418. Elevation zero reader’s handwheel. See figure 16.
420. Handwheel friction clutch. To prevent damage to the elfevation mechanism.
434. Binocular linkage clamp. See figure 16.
435. Observer’s azimuth handwheel. See figure 16.
436. Azimuth zero reader’s handwheel. This handwheel rotates the controller in azimuth and operates the D. E. C., which traverses the searchlight. This causes the pointer of the azimuth zero reader to move to its zero position when the searchlight is pointed according to sound locator azimuth data.
443. Azimuth drive clutch knob. With this knob in its released position the controller may be moved in azimuth when orienting without moving the azimuth zero reader’s handwheel.
445. Binoculars Self-explanatory.
446. Open sight See figure 16.
453. Binocular column lock clamp. See figure 16.
454. Binocular positioning handles. See figure 16.
456. D. E. C. switch This switch must be turned on before the D. E. C. will function.
463. Level See figure 16.
13. Power plants.—Q. What difference is there between the Sperry M1941 and the General Electric M1940 power plants? A. Very little. The engines are the same except the Sperry runs at 1,100 rpm and the General Electric at 1,200 rpm. The generators are made by different manufacturers, but both deliver 150 amperes at 78 volts to the searchlight.
Q. What is the rating of the generator of the M1940 General Electric power plant? A. It is rated as follows:
Volts Amperes Rpm Kilowatts
100 160 1,200 16.0
Q. Is the nomenclature of the Sperry and the General Electric power plants similar? A. Yes. Parts as shown in figures 10, 11, and 18 correspond except as follows:
(1) The General Electric tank holds 26 gallons.
(2) The General Electric tail lamp switch is located on the tail lamp.
(3) The General Electric fan is driven by a pulley from the main crankshaft.
41
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Figure 18.—General Electric M1940 power plant.
Section III
SOUND LOCATORS
Paragraph
General_____________________________________________________________________ 14
Ml series sound locators---------------------------------------------------- 15
M2 sound locator____________________________________________________________1 16
14. General.—Q. What is a sound locator? A. A sound locator is an instrument which can pick up and locate accurately an airplane by means of the sound it emits.
Q. What are the two types of sound locators now in use? A. The Ml series sound locators and the M2 sound locator.
Q. Of what does a sound locator consist? A.
(1) Horns for collecting sound.
(2) Sound track to listener’s helmet.
(3) Listener’s helmet.
(4) A mounting for the horns so that the locator may be moved in azimuth and elevation by handwheels.
(5) An acoustic corrector to correct for sound lag.
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 14-16
(6) A data transmission system to send corrected data to the searchlight so it may be pointed correctly.
Q. What is meant by sound lag? A. Sound travels in air at about 1,100 feet per second. This means that it takes the sound coming from an airplane some time to arrive at the sound locator. During this time, or sound lag, the airplane has traveled a certain distance.
Q. What is the function of the acoustic corrector? A. The acoustic corrector must correct the azimuth and elevation data for the sound lag.
15. Ml series sound locators.—Q. What is the weight of an Ml series sound locator? A. 2% tons.
Q. How many horns are used on the Ml sound locator? A. Four.
Q. Are all sound locators of the Ml series similar? A. Yes. From the M1A1 to the M1A8, they are all identical except for minor manufacturing changes.
Q. What kind of sights are provided for orienting the Ml series sound locator? A. Open sights. They are to be placed on the lower elevation horn.
Q. Point out and give purpose of the parts of an Ml series sound locator. A. See figure 19.
Q. What acoustic correctors are used with the Ml series sound locators? A. The Ml. M1A1, and the M2 acoustic correctors are used on the Ml series locators.
Q. How many men are required to operate the Ml series sound locator? A. Four men when the Ml or the Ml Al acoustic corrector is furnished. Three men when the M2 acoustic corrector is provided.
Q. What is the difference between the Ml and M1A1 acoustic correctors? A. The Ml has the azimuth scale graduated in degrees, the M1A1 in mils.
Q. Give the nomenclature of the Ml acoustic corrector. A. See figure 20.
Q. Give the nomenclature of the M2 acoustic corrector. A. See figure 21.
16. M2 sound locator.—Q. What is the weight of the M2 sound locator? A. 1,066 pounds.
Q. What are the six component parts for transportation of the M2 sound locator? A.
(1) Two horn assembly.
(2) Single horn assembly.
(3) Corrector assembly (in carrying case).
(4) Column.
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(5) Platform.
(6) Cable and cable reels.
Q. Which horn is a common horn for the azimuth and elevation listeners? A. Upper right horn, figure 23.
Q. How many men does it take to operate the M2 sound locator? A. Three. The azimuth and elevation listeners and the acoustic corrector operator under supervision of the chief of section.
Q. Give the nomenclature and state the purpose or use of each part of the M2 sound locator. A. See figure 23.
Figure 19.—Sound locator M1A1.
44
/7

/7
!8
~/8 20
2/ ./
/6
9
4
/6
2!
A
/3

24
25
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23
,<4

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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 16
Part
Purpose or use
1. Acoustic corrector ____
2. Jacks________________
3. Front seat (removed)____
4. Horns___________________
5. Traversing handwheel____
6. Elevating handwheel_____
7. Azimuth helmet.. ______
8. Elevation helmet________
9. Horn bearings___________
10. Azimuth circle__________
11. Turntable______________
12. Seats for operators____
13. Footrest_______________
14. Adjustable locking screws.
15. Horn locking frame_____
16. Traveling horn supports.
17. Hand clamp screws______
18. Horn support sections__
19. Elevation control shaft ...
20. Rubber tubes____________
21. Vertical columns_______
22. Towing bar_____________
23. Side frames____________
24. Covers for acoustic corrector.
25. Cable leading to the control station.
26. Brake handle___________
To correct for the sound lag angle.
There are four jacks for leveling the sound locator.
Sound locator listeners ride on this seat during road marches.
These four horns collect and amplify sound. Upper and lower horns are elevation horns. Right and left horns are azimuth horns.
The azimuth listener uses this handwheel to follow the airplane sounds.
The elevation listener uses this handwheel to fellow the airplane sounds.
The two azimuth horns are connected by sound track tubing to this helmet so the listener can hear the airplane sound.
The two elevation horns are connected by sound track tubing to this helmet so the listener can hear the airplane sound.
Bearings are mounted on the top of each vertical column so the horns may be elevated easily.
Used to orient the sound locator with the searchlight. The circle can be slipped around for adjustment.
The vertical column and horn assembly are supported and turn with the turntable.
The azimuth listener is seated on the left seat, the elevation listener on the right seat.
Each listener has a footrest.
Three screws are used to lock the turntable in azimuth for traveling on’ the road.
When the horns are mounted for traveling, this frame holds them rigidly in their traveling position.
The four horns are removed from their operating positions and put on these supports for traveling.
These clamp screws lock the horns in their operating position.
These sections support the horns in their operating position.
This shafting leads from the elevation handwheel to the gears which elevate the horns.
These are sound track tubes conducting the sound from the horns to the listener’s helmets.
These vertical columns support the horns.
Used for towing the sound locator by its towing truck.
These two frames are placed one on each side of the sound locator so that cables and other equipment will not fall off when on the road.
These removable wooden covers fit over the acoustic correctors for traveling.
Sound locator data are sent to the control station through this cable.
This operates the parking brake. The brakes are located on the rear wheels.
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Figure 20.—Acoustic corrector Ml.
Figure 21.—Acoustic corrector M2.
46
•Mfc TRANSMITTER . . ^REOTEOAZ.
SCALE
-EASING tOMOB „ SOUND LAG
UM ANO
Chart A«« ^tLEASINGKNOB ■ ELEVATION K-$CALE ELEVATION TRANSMITTER
JW*' ftmucrran
LW^BW&ICTION | S£*on«»4 i
'•^*1
LATERALRATE
INDEX
POINTER .ATERAL MULTIPLYING
W CM' WLTIPLYING CAM FOLLOWERS VWICAL MW.TWMG ’T' CAM ■^POINTER ■ticalrate Z, INDEX
C-WtREC W tEOiriON

-'«LtiTUD£.
I
LATERAL. RATE MATCHING KNOB
CORRECT ED AZ.
SCALE .
releasingmI knoe, H I
TM 4-330
GUNNERS1’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 16
Figure 22.—Corrector operator in action.
Part
Purpose or use
1. Multiplying pantograph...
This causes the pantograph ball to be offset by the sound lag angle both in azimuth and elevation.
2. Target air speed setting knob.
7. Pantograph attaching stud knob.
8. P arallax cam__________
9. Declutching gear_______
10. Target air speed scale_
11. Pantograph pointer and ball.
12. Mirror and cross lines_
13. Level__________________
Air speed of the target is set in on the miniature airplane which is positioned so as to be parallel to the target’s course.
Holds pantograph in correct position.
Parallax corrections are set in on the cam parallax scale.
Push down on this gear so that the parallax arrow may be pointed at searchlight.
Air speed of airplane is indicated in miles per hour. Use knob (2) to set in correct air speed.
The corrector operator centers the pantograph ball on the cross lines of mirror (12).
The image of the pantograph is seen in this mirror.
To level sound locator.
14. Elevation clamp_________
15. Parallax scale. ________
To lock horns at any desired elevation.
Set parallax cam to the correct figure on this scale.
47
h A A rio

..
'll'
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Q. Point out the the part (fig. 23) :
following parts and give the purpose or use of
Part
Purpose or use
Elevation scale___________
Sight crank handle and knob_
Azimuth handwheel_________
Elevating handwheel______
Azimuth scale_____________
Portable lamp receptacle__
Cable receptacle__________
Common horn_______________
Elevation horn____________
Azimuth horn______________
A scale graduated in mils for elevating the horns to any desired elevation.
The corrector operator uses this handle and knob to keep the pantograph ball centered in the sight mirror cross lines.
The azimuth listener uses this handwheel to track the sound source. There is an azimuth clamp knob on the shaft of this band wheel to lock the sound locator while orienting.
The elevation listener uses this handwheel to track the sound source.
For use in orienting the sound locator. The scale can be moved around to any desired azimuth.
For plugging in the trouble lamp.
Blue cable plug is inserted in this receptacle.
Used to collect sound for both azimuth and elevation. (Upper right horn, fig. 23.)
Used to collect sound for azimuth. (Lower right horn, fig. 23.)
Used to collect sound for azimuth. (Left horn, fig. 23.)
48
-E/evohon Scale r—Pantograph
Azimuth Handwheel
Sight
Correction Handle |
and >
Elevation Handwheel—' f
Portable Lamp Receptacle
Azimuth Scale-—■——
Cable Receptacle
Figure 23.—Sound locator M2.
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 17
Chapter 4
CARE AND OPERATION OF SEARCHLIGHT SECTION EQUIPMENT
t Paragraphs
Section I. Power plant___________________________________.__17-21
II. Searchlight____________________________________ 22-28
III. Control stations-^______________________________39-35
IV. Sound locator apparatus-------------------------36-40
Section I
POWER PLANT
Paragraph
General------------------------------------------------------------- 17
Operation____________________________________________________------- 18
Care of power generator-------:-----------.------------------------- 19
Care of engine----------------------------------------1------------- 20
Lubrication schedule of main parts of searchlight power plants------ 21
17. General.—Beginning with the M1934 portable power plant, al] models are fundamentally the same. This is especially true of the Sperry power plants of 1937. 1939, 1940, and 1941, and the General Electric power plant of 1940. The M-VI and M1934 mobile power plant generators are driven by the vehicle engines through suitable transmissions.
Q. What is the principal purpose of a power plant? A. To furnish direct current power to operate the arc.
Q. Name the two principal parts of a power plant. A. A gasoline engine (1) which furnishes motive power to drive a direct current generator (2).
Q. What is the purpose of a governor on the power plant? A. A governor is a device on an engine which controls the fuel supply to the engine in such a way that the engine-generator speed will remain constant from no load to full load.
Q. What is supplied to control the power output of the generator? A. AH necessary control apparatus, motors, and engine indicators mounted on a control panel.
Q. How does the engine adjust itself between “arc load” and “listening load” conditions? A. Automatically. The governor control sys-
,422589°—42----4
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50
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21
Figure 24.—Control panel, Sperry M1941.
25 2€ 29 24. 39 23 40
i i /
27
28
32
31
30
38 33 3 4 35 36 37
21. Main switch.
22. Power ammeter.
23. Power voltmeter.
24. Voltage regulating rheostat.
25. Gasoline gage.
26. Charging motor.
27. Tachometer and revolution counter.
28. Oil pressure gage.
29. Temperature gage.
30. Choke control.
‘31. Starter button.
32. Throttle control.
33. 115-volt light switch.
34. Fan season switch.
35. Ignition switch.
36. 6-volt light switch.
37. 6-volt receptacle.
38. 115-volt receptacle.
39. 115-volt panel lights.
40. 6-volt panel lights.
Note.:—Control panel for Sperry M1940 same as for Sperry Ml 941 except that circuit breaker is substituted for main switch.
TM 4-330
GUNNERS' INSTRUCTION, AA SEARCHLIGHT BATTERIES 17
51
Ammete r
——— (Q1 Main Power —— Switch
(10)
Ammeter Temperature goge (28)
100-Volt Light (4)
\ 6-Volt Light (3)
Generator field \
Rheostat \ (?) \
\ Voltmeter (6)
Fuel gage <9) TachometgxJI
(3o) i OH pressure! S°^(29)|
(18)
04) (|3> (/2)
oh / / / r ) Pull out choke and throttle about half way.
(c) Start engine by turning on ignition switch and pressing starter button. After engine starts, adjust the choke for smooth operation and pull the throttle all the way out. After the engine has warmed up and has been operating smoothly for a few minutes, push the choke back in.
(2) Portable power plant M193J^.—{a) Throw main switch to off position.
(Z>) Turn on ignition switch.
() Voltage and current adjustment should be made with the arc load on.
(2) Sperry M1937 and M1939.—The governor and generator voltage control equipment has two operating positions, listening load and arc load. Therefore two separate rheostats are provided.
(a) At listening load speed (875 to 900 rpm) the listening load rheostat should be adjusted so that the generator delivers 10 to 15 amperes at 100 to 110 volts.
(&) At arc load speed (1,200 rpm) the arc load rheostat should be adjusted so that the generator delivers 165 amperes at 100 volts.
(3) M1934 portable.— («) Set the voltage manual rheostat on the painted marks. This rheostat controls the voltage directly when the voltage regulator and electrical governor are disconnected. Under automatic operation, the proper setting of this rheostat is necessary so that the engine will run at the proper speed while generating the proper voltage.
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() Set the voltage automatic rheostat on the painted marks. This rheostat provides a fine adjustment of the voltage by changing the setting of the voltage regulator.
(c) With the rheostats set on the painted marks as indicated, the generator should develop approximately 100 volts at approximately 850 rpm with a hot engine. If this operating condition is obtained, it will indicate that the electrical governor is functioning. It may be necessary to shift the rheostat settings very slightly to obtain the above desired values. After these settings are made, no further adjustments of the rheostats will normally be required while operating the searchlight.
(4) M1934 mobile.—The M1934 mobile power plant has incorporated in it an automatic voltage regulator which maintains approximately constant voltage regardless of current fluctuations. The desired voltage is set by the voltage adjustment rheostat, located on the upper right hand side of the control panel. The knob of the rheostat is turned clockwise to increase the voltage and counterclockwise to decrease the voltage. The normal operating voltages are 98 volts with 150 amperes arc load, and 101 volts with a listening load speed of 900 rpm.
(5) M-VJ.—With the searchlight in operation, and the power plant running at a speedometer speed of 25 mph, adjust the generator field rheostat so that the voltage of the generator is 100 volts. The ammeter should then indicate approximately 150 amperes.
Q. In case of an emergency, how would you manually control the engine speed and voltage? A.
(1) Sperry M19JA, M191fi, and General Electric M1940.— (a) The first precaution is to make certain that the governor arm is blocked (tied) in the forward position to prevent interference from the governor itself.
(6) With throttle adjusted to a setting of approximately normal arc-load speed, start engine, allow it to warm up, and then strike the arc. Adjust the throttle until the tachometer indicates normal arcload speed with the arc burning.
(c) If required, adjust the voltage regulating rheostat until the ammeter indicates the proper current.
(d) When the arc is cut off, the throttle at the power plant must be readjusted immediately to prevent overspeeding and excessively high voltages.
Note. Do not readjust the voltage regulating rheostat after it has once been adjusted for arc load.
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(2) Sperry M1939 and M1937.— (a) Block the governor arm in the forward position (tie it) to prevent interference from the governor.
(Z>) Set the throttle at listening speed. When the arc is struck, adjust the throttle to obtain the normal arc-load speed.
(c) When changing from arc load to listening load, quickly push in the throttle simultaneously with the removal of arc load to decrease engine speed. This must be done to avoid overspeeding and excessively high voltage.
() Release mechanical governor thumb nuts to permit the rod to go to limit of its travel into the panel.
(c) Turn voltage manual rheostat to the extreme clockwise position.
(<7) Pull out mechanical governor rod and lock it at the no-load speed of 1,150 rpm.
(e) Adjust voltage manual rheostat until the no-load voltage is 110 volts.
(/) When the arc is struck, adjust voltage manual rheostat to 98 volts when searchlight arc is drawing 150 amperes.
() Push throttle all the way in to allow the engine to slow down to idling speed.
( 0
TM 4-330
22 COAST ARTILLERY CORPS
(1) The arc voltage varies directly as the arc length.
(2) The arc current varies inversely as the arc length.
Q. What are the dimensions and burning time of the carbons? A.
Burning time
Carbon Size {approximately)
Positive 22 inches by 0.633 inch outside diameter 1% hours
Negative 12 inches by 0.434 inch outside diameter iy2 hours
Q. When recarboning should you use new carbons? A. Yes, always use a pair of full length carbons.
Figure 28.—Schematic diagram of the Sperry M1941 lamp and lamp control mechanism.
62
14 18 190 169
204 198/ 207/
.188
-13
-191
-197
24
16
,27
I-
2
IO
3-
26
;205 / 192; t V 17 \\ 15
25,
206 202 ' 12
22
20
19 186 187
29
28 35 31 34
200 \ \\ 194
32
-193
195
z2l
23
199 '30
9
201 ,203
33
|A4
T
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 22-23
1. Negative carbon.
2. Negative release lever.
3. Negative control rod.
4. Negative feed pawls.
5. Negative feedback ratchet.
6. Pawl guards controlling negative feed.
7. Negative feed forward ratchet.
8. Negative hand feed knob.
9. Negative feed centralizer lever.
10. Negative carbon release spring.
11. Negative feed pawl spring.
12. Negative terminal.
13. Positive carbon.
14. Positive contact.
15. Positive terminal.
16. Positive control rod.
17. Positive feed control electromagnet.
18. Positive feed gear.
19. Positive hand feed lever.
20. Positive hand feed lever spring.
21. Positive hand feed handwheel.
22. Positive feed shaft.
23. Positive feed rate adjustment screw.
24. Positive feed shaft pin and spring.
25. Thermostat.
26. Thermostat lens.
27. Lens positioning screw.
28. Arc length control coil.
29. Reciprocating feed member.
30. Feed motor.
31. Counterbalance.
32. Adjustment spring.
33. Arc length adjustment screw.
34. Eccentric disk.
35. Balanced armature.
186. Eccentric shaft gear.
187. Gear train.
188. Driving miter gear.
189. Driven miter gear.
190. Ratchet and positive feed gear assembly.
191. Spring loaded/feed plunger.
192. Plunger spring.
193. Eccentric cam.
194. Roller arm contacts.
195. Switch.
197. Plunger operating armature.
198. Recarboning key.
199. Worm.
200. Worm wheel.
201. Condenser.
202. Focusing bracket set screw.
203. Resistor.
204. Positive carbon feed rollers.
205. Yoke.
206. Planetary gear.
207. Main positive feed bearing.
23. Operation of lamp and lamp control mechanism, M1941 Sperry searchlight.—Q. Describe briefly the operation of the lamp control mechanism. A. The lamp control mechanism and lamp are shown in schematic form in figure 28.
(1) Positive carbon feed system.—The feed motor (30) drives, through a set of gears, the positive rod (16) which drives miter gear (188) and a driven miter gear. Miter gear (189) drives a yoke carrying with it a set of gears. This set of gears includes a ratchet and gear assembly (190) which, when prevented from rotating by a feed plunger (191), causes a planetary gear (206) to rotate, which in turn causes the feed rollers to rotate, thus feeding the positive carbon forward.
(2) Negative carbon feed system.—The negative carbon feed system operates as follows: The feed motor (30) drives through eccentric gear (186), which in turn causes the reciprocating feed member (29) and the feed pawls (4) to oscillate back and forth. One of the feed pawls (4) (depending upon the position of the negative feed control guard (6) drives the negative control rod (3) so as to feed the negative carbon forward. The other pawl (4) drives the control rod in the opposite direction so as to retract the negative carbon. The negative control rod (3) is connected to the feed rollers which position the negative carbon.
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Q. What operates the positive feed plunger (191), figure 28? A. An electromagnet which may be energized from two sources: a cam operated switch (195) or thermostat (25).
Q. What is the purpose of the thermostat? A. The positive carbon burns back twice as fast as the normal rate of feed, therefore the thermostat functions to give the positive carbon an additional forward feeding to keep the luminous ball of vapor at the focal point of the mirror.
Q. How does the thermostat function? A. It is a thin strip of two different metals welded into a single strip. When heated this strip will bend because the two metals have different-rates of expansion. When rays of light from the positive crater are focused by the thermostat lens (26) on to the bimetallic strip, the strip bends and closes an electrical contact which in turn energizes the positive feed electromagnet.
Q. What is the function of the arc length control coil (28) ? A. It acts as a magnet on armature (35), which in turn positions negative feed pawl guard (6), allowing ratchet (5) to retract the negative carbon when the arc voltage is less than 78 volts. Ratchet (7) is engaged when the voltage is greater than 78 volts. Thus it keeps the negative carbon positioned so as to maintain a constant arc length. It functions on the electrical principle that the arc voltage varies directly with the arc length.
24. Operation of lamp and lamp control mechanism, M1940 Sperry searchlight.— (M1939. M1937. M1934. and M-VI are similar.)
C- Describe briefly the operation of the lamp control mechanism. A. The control mechanism and lamp are shown in schematic form in figure 29.
(1) Positive carbon feed system.—The feed motor (30) drives an eccentric disk (34) causing the reciprocating feed member (29) and positive feed pawl (20) to move back and forth. Positive feed pawl (20) engages the teeth on positive feed ratchet (18), rotating it and the positive control rod (16) in a counterclockwise direction. Control rod (16) drives gear (36), causing a yoke carrying planetary gear (38) to rotate. Planetary gear (38), through a worm drive, causes the carbon feed rollers to rotate and feed the positive carbon forward.
(2) Negative carbon feed system.—The reciprocating feed member (29) and the feed pawls (4) oscillate back and forth. One of the feed pawls (4) (depending upon the position of the negative feed control guard (6)) drives the negative control rod (3) so as to feed
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the negative carbon forward. The other pawl (4) drives the control rod in the opposite direction so as to retract the negative carbon. The negative control rod (3) is connected to the feed rollers which position the negative carbon.
Q. What is the normal current and voltage of the arc? A. The arc should operate with a current of 150 amperes and a voltage of 78 volts.
Q. What is the function of the positive feed control guard (19) ? A. Raising the positive feed control guard permits more teeth on the positive feed ratchet (18) to be engaged by positive feed pawl (20), thereby increasing the rate of feeding of the positive carbon. The opposite condition occurs when the guard (19) is lowered. The normal position of the positive feed control guard (19) is such as to allow the positive feed pawl (20) to engage only 1 tooth on the positive feed ratchet (18) for each stroke of the feed pawl.
Q. What actuates the positive feed control guard (19) ? A. The positive feed control guard can be positioned, automatically or manually, as follows:
(1) Manually.—By turning the positive feed rate adjustment knob (23), the position of the positive feed control guard (19) can be controlled, and therefore the rate of feeding of the positive carbon.
(2) Automatically.—The positive feed control electromagnet, when energized, will raise the positive feed control guard (19), thereby increasing the feeding of the positive carbon.
Q. What energizes the positive feed control electromagnet (17) ? A. The closing of the contacts of the bimetallic strip in the thermostat (25).
Q. How does the thermostat function? A. The thermostat consists of a thin strip of two different metals welded into a single strip. When heated these strips will bend because the two metals have different rates of expansion. When rays of light from the positive crater are focused by the thermostat lens (26) on to the bimetallic strip, the strip bends and closes an electrical contact which in turn energizes the positive feed electromagnet, causing the positive crater to return quickly to the focal position.
Q. What is the function of the arc length control coil (28) ? A. It acts as a magnet on armature (35), which in turn positions negative feed pawl guard (6) allowing rachet (5) to retract the negative carbon when the arc voltage is less than 78 volts. Ratchet (7) is engaged when the voltage is greater than 78 volts. Thus it keeps the negative carbon positioned so as to maintain a constant arc length. It functions on the principle that the arc voltage varies directly with the arc length.
422589°—42--5 65
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66
39
37
38
36

^13
10-
27
2
3
26
15
12.
,16
25
18
17
.20
19
23
22
21
23
11
6, 5
7 6
6
9
28
33
32
-35
31
21
30
34,
Figure 29.—Schematic diagram of the Sperry Ml 940 lamp and lamp control mechanism.
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1. Negative carbon.
2. Negative release lever.
3. Negative control rod.
4. Negative feed pawls.
•5. Negative feedback ratchet.
6. Pawl guards controlling negative feed.
7. Negative feed forward ratchet.
8. Negative hand feed knob.
9. Negative feed centralizer knob—for hand feed.
10. Negative carbon release spring.
11. Negative feed pawl spring.
12. Negative terminal.
13. Positive carbon.
14. Positive contact.
15. Positive terminal.
16. Positive control rod.
17. Positive feed control electromagnet.
18. Positive feed ratchet.
19. Positive feed control guard.
20. Positive feed pawl.
21. Positive hand feed knob.
22. Positive feed pawl spring.
23. Positive feed rate adjustment knob.
24. Positive feed electromagnet spring.
25. Thermostat.
26. Thermostat lens.
27. Lens positioning screw.
28. Arc length control coil.
29. Reciprocating, feed member.
30. Feed motor.
31. Counterbalance.
32. Adjustment spring.
33. Arc length adjustment screw.
34. Eccentric disk.
35. Balanced armature.
36. Gear.
37. Fixed gear.
38. Planetary gear.
39. Recarboning wrench (shown in position for recarboning only).
25. Operation of Sperry searchlights.—Q. In what two ways can the arc be struck? A. Automatically or manually.
Q. Describe each briefly. A.
(1) Automatically —With the lamp control mechanism set for automatic operation, close the arc switch. The negative carbon will automatically strike the arc and maintain the proper arc length.
(2) MamuaUy.—First, centralize the negative feed pawls by moving the negative feed centralizer lever (or knob) to the hand position. This will allow feeding of the negative carbon by hand. Second, move the negative carbon forward by means of the negative hand-feed knob. Third, after striking the arc, retract the negative carbon until the voltmeter reads approximately 78 volts.
Q. In the 1941 Sperry light what automatic provision is made to strike the arc quickly? A. The arc switch incorporates an additional switch known as a thermal-operated circuit breaker. This circuit breaker is designed to close 5 to 7 seconds after the main arc switch is opened. The closing of the circuit breaker causes the negative carbon to feed forward rapidly, attempting to strike a new arc. When the carbons touch, a short-circuit condition is caused which opens the circuit breaker and prevents the restriking of the arc. Thus the negative carbon is left in contact with the positive carbon and is in position for a quick strike of the arc.
Q. What are the dimensions and burning time for the carbons ? A.
Burning time
Carbon Size (approximately)
Positive— 22 inches by 0.633 inch outside diameter li/2 hours Negative 12 inches by 0.434 inch outside diameter 1% hours
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Q. When recarboning, should you use new carbons? A. Yes, always use a pair of full-length carbons.
Q. Before entering the drum what should you do? A. Make sure that the arc switch is open. In the Sperry M1941 light be especially sure that the recarboning safety switch has been thrown to the recarboning position.
Q. How would you insert a new positive carbon? A. Spread the feed roller brackets apart by means of the recarboning key. Insert the new carbon until it projects 1Ti6 of an inch beyond the positive nose cap. Turn the recarboning key slowly until it permits the positive rollers to grip the carbons.
Q. Explain the recarboning of the negative head. A. Push the lower end of the negative carbon release lever toward the positive head so that the negative carbon may be readily inserted through the rear of the head. Move carbon in until it projects approximately one inch beyond the negative nose cap. Return the release lever slowly to its norma] position. Never allow the lever to snap back as this may break the negative carbon.
Q. How could you operate the searchlight if the thermostat or the positive control electromagnet failed? A.
(1) Sperry Ml91^1.—Turn the positive feed rate adjustment screw approximately one and one-fourth turns counterclockwise toward “semi.” The position of the positive carbon should be carefully watched to keep it at the focal center. The positive carbon can be fed forward by depressing the positive hand feed lever whenever the positive carbon is behind the focal point.
(2) Sperry M191>0, M1939. M1937, M1931^ M-VI.—Turn the positive feed rate adjusting knob (23) counterclockwise toward “semi.” The positive carbon will feed forward at a rate so as to approximately position the positive crater at the focal point. Because of the absence of automatic control, the position of the carbon should be watched carefully through the ground glass view finder to prevent over or under feeding.
Q. How could you operate the searchlight if the arc length control coil should fail? A. Set the negative feed centralizer lever or knob to hand position and turn the negative hand feed knob so as to maintain the required searchlight voltage of 78 volts.
Q. How is the interior of the lamp drum kept cool during operation? A. There is a small motor-driven fan on top of the searchlight drum which draws air from openings at the bottom and side of the searchlight and exhausts the hot gases out through the top.
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26. Maintenance of Sperry searchlights.—Q. Should coarse sandpaper ever be used on the searchlight? A. No. Unless otherwise specified, use No. 00 sandpaper whenever an abrasive is required for cleaning this equipment.
Q. How often should the negative head contact surfaces be cleaned? A. After every third change of carbons. Wrap a piece of No. 00 sandpaper around a negative carbon stub and work it back and forth in the negative head. Clean all abrasive materials from the surfaces.
Q. How often should the positive carbon contact surfaces be cleaned? A. After every tenth change of carbons. The brushes must be removed. Then with No. 00 sandpaper around a positive carbon stub move it back and forth between the two brushes. Wipe off all dust.
Q. Should the carbon contact surfaces ever be reamed out? A. Only in extreme circumstances.
Q. What lubrication is necessary after every 10 hours of operation ? A. If the lamp has been lubricated with a graphite and oil mixture, place a few drops of a mixture of machine oil and kerosene on the bearings and gears of the lamp mechanism. If the lubricant Aquadag has been used this is not necessary.
C- What cleaning and lubrication of the lamp mechanism are necessary after every 50 hours of operation? A. If Aquadag has been used, no cleaning is necessary. In any case, at periods of 2 months, the entire lamp mechanism must be washed thoroughly with gasoline with the exception of the positive drive pinion bearing, the main positive feed bearing, and the roller bearing in the semifixed gear (all ball and roller bearings). Aquadag may be used as a lubricant. When Aquadag is used, apply with a spray gun when the lamp head is hot.
Q. What else should be lubricated every 50 hours of operation (or every 2 months) ? A.
(1) The ventilating motor bearings (accessible after removing the ventilating motor fan housing) should have a small amount of medium motor oil at the time the motor is inspected (once every 3 months).
(2) Feed motor bearings should be oiled and the feed motor worm gear should be greased with a high temperature grease every 3 months.
(3) The feed mechanism ball bearings must be oiled with light machine oil from inside the drum.
(4) All alemite fittings must be greased at least once a month.
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(5) Azimuth and elevation control (training) motors must be oiled once a month with medium oil.
Q. How should the mirror be cleaned? A. It should be cleaned only with the solution supplied for that purpose, and cotton pads should be used for applying and removing the cleaning agent. Do not allow the solution to accumulate on the mirror supporting clips. Before using this solution the mirror should be dusted off lightly with a soft camel’s-hair brush. Never clean the mirror with a rotary motion; always pass the pad over the mirror surface from the center toward the edge. The cleaning solution contains ammonia, so be sure to have sufficient ventilation inside the drum when using it.
Q. How is the thermostat cleaned? A.
(1) Remove the thermostat from the searchlight drum and place it on a suitable flat surface, preferably a workbench.
(2) Remove the four cover screws and cover.
(3) Unscrew the contact assembly holding screws and remove the contact assembly.
(4) Clean the points with crocus paper, being careful not to bend the contact arms and to avoid excessive rubbing with the abrasive.
(5) When finished cleaning, draw a piece of white paper between the contacts to wipe off any abrasive that may be left on the points.
(6) Reassemble the thermostat and replace it in its position in the drum.
Q. How are the supply and control slip rings cleaned? A. Access to these rings may be had through the handhole plate in top of the base of the searchlight. The rings should be cleaned with alcohol whenever necessary—at least every 3 months. Use No. 00 sandpaper, if necessary, to clean any burned spots.
Q. How should the carbons be protected? A. Keep the carbons dry and protect them against jarring that might crack the carbons or their cores.
Q. How are the motor brushes cleaned? A. After every 50 hours of operation remove the brushes and wash them in gasoline. Wash each brush and replace in its original position. Make sure that the brushes slide freely in their holders.
Q. How and when should the time delay mechanism of the M1941 searchlight be lubricated? A. It should be lubricated with light machine oil at intervals as determined by inspection.
27. Operation of General Electric Ml940 searchlights— Q. Describe briefly the operation of the General Electric lamp mechanism. A.
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(1) Positive feed.—See figure 30. The lamp motor, through a set of gearing and shafts, drives a helical gear on the positive head, which transmits a constant rotary motion to the yoke and positive carbon. When the detent is not engaged with the detent gear, the entire assembly, including the spur gear, rotates with the yoke. When the detent is engaged with the detent gear, the spur gear attached to the detent wheel is kept from rotating, causing the outside gear to rotate around the attached spur gear, thereby causing the feed rollers, through a worm drive, to feed the positive carbon forward.
(2) Negative feed.—The lamp motor, through a set of bevel gears, rotates the negative drive shaft. Mounted on and keyed to this shaft is a sliding armature friction driver which rotates with, but is free to slide along, the shaft. On each end of the sliding armature friction driver is a friction collar, either of which by proper positioning of the sliding armature can drive a friction-driven disk. This friction-driven disk is connected by shafting and gearing to the negative feed pawls. Positioning of the sliding armature friction driver is controlled by two stationary electromagnets, each of which is built around one of the friction collars. One of these electromagnets is termed the feed coil and the other the retract coil. When the feed coil is energized, the sliding armature friction driver is positioned so that the friction-driven disk is rotated in the proper direction to cause the feed rollers to feed the negative carbon forward. When the retract coil is energized, the direction of rotation of the friction-driven disk is reversed and the negative carbon is retracted.
Q. What actuates the detent? A. The positive feed magnet, when energized, causes an armature to turn; this turns a shaft which causes the detent to engage the detent gear. This armature may also be actuated manually by pushing the manual positive feed.
Q. How is the positive feed magnet energized? A. It may be energized from two sources:
(1) By the thermostat, whenever the positive carbon burns back from the focal point of the mirror.
(2) By the closing of the positive feed contacts which are actuated by rotation of a cam. This provides an intermittent feed to the positive carbon which is somewhat less than the rate of burning of the positive carbon.
Q. Can the positive feed rate be adjusted? A. Yes, by turning the manual positive feed adjustment knob. This knob provides for a rate of feed from a minimum of 6.5 inches per hour to a maximum of 12 inches per hour.
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72
CURRENT REGULATOR "-------------------------------------------
Figure 30.—Schematic diagram of General Electric lamp control mechanism and lamp mechanism.
~ FROM POWER PLANT
©SLIDING ARMATURE FRICTION DRIVER ©MANUAL NEGATIVE DRIVE
©POSITIVE FEED MAGNET COIL
CONCAVE MIRROR
THERMOSTAT X CONTACT—,
I POSITIVE CARBON "-HELICAL x^GEARS
•Apur GEAR '-DETENT\' ATTACHED nFTFMT
TO DETENT WHEEL *JEEl
\yoke'\

WORM, _ /rY0KE<^
\ ^FEED /feec\ \ rollers ROLLERS \
v-WORM GEAR
SLIDING COUPLING
> NEGATIVE CARBON-.
—INSULATION COUPLINGS
SINGLE THREAD WORM RIGHT HAND I—OVER RUNNING
CLUTCH
LAMP MOTOR
TW POSITIVE V\ XY^FEED \ \ CONTACTS \ y-/ Lfeeo cam \\ PUSH AND TURN FOR' MANUAL DRIVE
I TO INCREASeX**7 [POSITIVE FEED RATE ^-RETRACT contacts
4-current (regulating coil
ARMATURE SPRING-1 J ARMATURE f
MANUAL-^
POSITIVE FEED
FEED COIL—, / / 77/ /
FEEDAC^xJ\FRICTI0y *7 ! ( I
/DRIVEN/ M C?
RETRACT-X/VV disc 7 © V) /detent - ) ARMATURE^ /
/A,'
RETRACT-^ //L/nrly/ coil // /\h/y,''7yp/7 V /DMA
retract / / //x/W\!
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 27
Q. Can the positive carbon be fed forward manually? A. Yes, by pushing in and turning the manual drive crank clockwise, at the same time pushing in the manual positive feed button.
Q. What should be done if the thermostat fails? A. By observing the positive arc crater on the arc image screen, the crater can be moved to the focal point by simply pushing in the manual positive feed button and holding it until the positive crater returns to the focal point.
Q. How is the negative carbon kept at its proper position? A. By means of the current regulator, which is electrically connected to the feed coil and retract coil.
Q. How does the current regulator operate? A. The current regulator operates on a current principle. When the arc length is normal the current through the regulator is 150 amperes. This condition will cause the movable contact to be centered and neither the feed coil nor retract coil will be energized. When the current increases or decreases from the normal value of 150 amperes, as a result of a change in the arc length, the movable contact on the regulator will move to close either the feed coil circuit or the retract coil circuit. This in turn will cause the carbon to resume its normal position.
Q. Can the negative carbon be fed or retracted manually ? A. Yes, by pushing in the manual negative drive and turning the crank in the desired direction.
Q. How is the lamp kept cool? A. There is a small motor-driven fan located on top of the searchlight which draws air from openings in the drum and through the lamp support column.
Q. How can the arc be struck? A. Either automatically or manually.
(1) Automatically.—Close the main switch. The current regulator will cause the negative carbon to feed forward rapidly until the negative carbon touches the positive carbon. The rush of current will cause the retract coil to operate and retract the carbon quickly to its normal position where it will draw 150 amperes.
(2) Manually.—Push in the manual negative drive and turn the crank clockwise to feed the negative carbon forward until it strikes the positive carbon. Then quickly turn the crank counterclockwise and retract the carbon until the normal current of 150 amperes is indicated on the ammeter. When the manual negative drive crank is pushed in, an electric interlock opens the circuits of the magnetic clutch coils, thus preventing the automatic negative drive mechanism from functioning.
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Q. When using the distant electric control, what actually positions or trains the searchlight? A. Two small direct current motors, one ' for training in azimuth and the other for training in elevation.
Q. What should you check before entering the drum? A. Make sure the arc switch is open.
Q. How is the lamp recarboned? A.
(1) Positive carbon.— (a) Release feed rollers by means of the feed roller clamp lever.
(&) Insert new carbon through the hole in the positive head.
( 35
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29. General.—Q. How can the searchlight be controlled or trained? A. Two means are provided:
(1) The extended hand controller.
(2) The distant electric control.
Q. What does the control station accomplish? A.
(1) Provides remote control of the searchlight.
(2) Synchronizes the searchlight with sound locator data.
(3) Positions the binocular and open sight assembly.
Note—The Sperry M-VI does not have a binocular mount.
30. Sperry M1941, Ml940, M1939, and M1937 control stations.—^. Of what does the control station consist? A. It consists of a tripod, control unit, and binocular mount.
Q. How is the searchlight synchronized with the sound locator data? A. Self-synchronous transmitters on the sound locator transmit electrically the angular movements of the sound locator to self-synchronous receivers which are mounted and geared to the searchlight. The electrical output of the receivers goes to a phase detecting circuit, thence to direct current, double throw, zero reading voltmeters. When the indicator on the zero reading voltmeter is at the zero position, the searchlight is pointed or synchronized with the sound locator data. There are a total of four zero reading voltmeters, two for azimuth and two for elevation. One set (one azimuth and one elevation) of zero readers is mounted on the searchlight drum, and the other set is mounted on the control station.
Q. How many men are required to operate the control station? A. Three: an azimuth zero reader operator, an elevation zero reader operator, and an observer.
Q. What are the duties of each man? A.
(1) The zero reader operators turn their respective handwheels to keep the zero pointers on the center or zero position of the azimuth and elevation zero reader indicators. If the target is not flicked when the searchlight goes into action, the zero reader operators cause the searchlight (except in the M1937 control station) to search in the vicinity of the sound locator data by operating their handwheels so as to cause the pointers of the zero reader meters to move slowly, alternately to the right and left of the zero position. In the M1937 control station an automatic means is provided for searching; pushing down the search control knob operates an automatic search in elevation; turning the search control knob offsets the potentiometer which controls the pointer of the azimuth zero reader; thus the observer controls an automatic search in elevation, and a search in azimuth by offsetting the pointer of the azimuth zero reader.
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(2) When the target is flicked the zero reader operators relinquish control of their respective handwheels and the observer then takes over the control and follows the target by means of the observer’s handwheels.
Q. What is actuated when the azimuth zero reader’s handwheel, or observer’s azimuth handwheel, is turned? A. The control unit is turned in azimuth and the azimuth distant electric control transmitter is driven in azimuth. This causes the searchlight also to be moved in azimuth.
Q. What is actuated when the elevation zero reader’s handwheel, or observer’s elevation handwheel, is turned? A. The binocular mount is moved in elevation and the elevation distant electric control transmitter is driven in elevation. This causes the searchlight to be elevated or depressed.
Q. Is there a means of signaling at the control station? A. Yes. There is a push button on the control station that operates a buzzer on the searchlight. On the M1941 control station there is a buzzer which is operated by a push button at the sound locator.
Q. What is the color of the control cable plugs and receptacles?
A. Red.
Q. What is the minimum distance that the control station should be placed from the searchlight? A. 50 feet.
Q. What type of distant electric control is used on Sperry searchlights, with the exception of the M-VI? A. A direct current step-by-step system, which operates on the same voltage as does the arc.
31. Sperry M1934 control station.—Q. Of what does the control station consist? A. It consists of a tripod and control unit, including binoculars.
Q. How is the searchlight made to follow the sound locator data?
A. Self-synchronous transmitters on the sound locator transmit, electrically, the angular movements of the sound locator to self-synchronous receivers, which are mounted in the control station and position an inner dial of a set of concentric dials. The outer dials are geared to the control unit and indicate the azimuth and elevation of the control unit and searchlight when correctly oriented and synchronized.
Q. How is searching accomplished? A. The searching is accomplished by a searching handwheel which superimposes an additional motion to the elevation and azimuth transmitters.
Q. How many men are required to operate the control station? A. Three: observer, azimuth follow-the-pointer operator, and elevation follow-the-pointer operator.
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Q. What are the duties of each man? A. The follow-the-pointer men at the control station operate their handwheels so as to keep the searchlight dials continuously matched with the sound locator dials. If the target is not flicked, the observer should start searching by turning the searching handwheel continuously in a clockwise or counterclockwise direction. When the target is flicked, the follow-the-pointer men should relinquish control of their respective handwheels to the observer, who from then on follows the target by means of the observer's handwheels.
Q. What type of distant electric control is used on the Ml934 Sperry searchlight ? A. A direct current step-by-step system, which operates on the same voltage as does the arc.
32. Sperry M-VI control station.—Q. Of what does the control station consist? A. It consists of a tripod, controller, and comparator.
Q. How is the searchlight made to follow the sound locator data? A. Self-synchronous transmitters on the sound locator transmit, electrically, the angular movements of the sound locator to self-synchronous receivers, which are mounted in the comparator and positions an outer dial of a set of concentric dials. The inner dial is positioned by a self-synchronous receiver which is electrically connected to a self-synchronous transmitter on the searchlight. Operating the controller handwheels causes the searchlight to be trained in elevation and azimuth, and when the pointers on these two concentric dials at the comparator are matched, the searchlight is pointing in the proper direction, if the searchlight unit has been correctly oriented and synchronized.
Q. How many men are required to operate the control station ? A. Three: observer, azimuth follow-the-pointer operator, and elevation follow-the-pointer operator.
Q. What are the duties of each man? A. The follow-the-pointer men at the control station operate their handwheels so as to keep the searchlight dials continuously matched with the sound locator dials. If the target is not flicked the follow-the-pointer men cause the searchlight to search around the sound locator data by manipulating their respective handwheels so as to cause the searchlight pointer to move slowly back and forth within 5° of the sound locator pointer.
Q. What type of D. E. C. is used by the M-VI searchlight? A. A brush shifting type. The handwheel at the comparator positions a d-c step-by-step transmitter which in turn positions a d-c step motor
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 32-34 at the searchlight, causing the brushes of the training motor to be shifted, imparting a torque to the training motor.
33. Maintenance of Sperry control stations.—Q. Should the azimuth gear and pinion be lubricated? A. No. They should be cleaned once a month with gasoline and never lubricated, as lubricating will cause dust and dirt to gather on the gear teeth.
Q. How should the electrical contact rings and brushes be cleaned? A.
(1) Clean with alcohol when needed. Use No. 00 sandpaper if necessary to clean burned spots.
(2) The slip rings and brush assemblies in the tripod should be cleaned every 6 months.
(3) The D. E. C. transmitter rings and segments should be cleaned every 3 months.
(4) All electrical contacts should be clean and bright. Wipe off all contacts after using an abrasive. Do not permit oil or grease on the insulation.
Q. How should the control station be lubricated? A. Due to the fact that most of the control unit mechanism bearings are grease-sealed at the factory, little attention to lubrication is required. However, when the control unit cover is removed for cleaning, the gear teeth and bearings should be inspected and a few drops of machine oil applied as necessary.
34. General Electric Ml940 control stations.—Q. Of what does the control station consist? A. It consists of a tripod, control unit, and binocular mount.
Q. What type of D. E. C. is used by the General Electric M1940 searchlight ? A. A self-synchronous control system which controls the operation of the d-c training motors.
Q. How are data transmitted from the sound locator? A. From self-synchronous transmitters on the sound locator to receivers on the searchlight, then to zero reading voltmeters on the searchlight and control station.
Q. How are the movements of the control station transmitted to train the searchlight? A. The rotation of the handwheels at the control station positions a self-synchronous transmitter, which in turn causes a rotor on the searchlight self-synchronous receiver to follow the rotation of the transmitter rotor. The rotor on the searchlight receiver positions a heart-shaped cam which controls a contact operating plate in a resistance bridge. Movement of the contact operating plate changes the bridge resistance in such a way as to control the operation of a direct current driving motor on the searchlight. When
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the searchlight has been rotated the required amount, the heart-shaped cam is set back to its neutral position in the following manner: A system of gears from the searchlight turns the stator housing of the self-synchronous receiver in the opposite direction to that of the receiver rotor. This movement is reflected in a corresponding rotor movement which returns the heart-shaped cam and contact operating plate to the neutral position.
Q. How many revolutions of the distant electric control transmitters and receivers correspond to one revolution of the searchlight? A. Tlie D. E. C. transmitters and receivers make 36 revolutions for each revolution of the searchlight. Therefore, the control station and the searchlight will be auto-synchronous only in a 10° arc.
Q. How many men are required to operate the control station? A. Three: an azimuth zero reader operator, an elevation zero reader operator, and an observer.
Q. What are the duties of each man? A. The zero reader operators turn their respective handwheels to keep the zero pointers on the center or zero position of the azimuth and elevation zero reader indicators. If the target is not flicked when the searchlight goes into action, the zero reader operators cause the searchlight to search in the vicinity of the sound locator data by operating their handwheels so as to cause the pointers of the zero reader meters to move slowly, alternately to the right and left of the zero position. When the target is flicked the zero reader operators relinquish control of their respective handwheels and the observer then takes over the control and follows the target by means of the observer’s handwheels.
Q. What is actuated when the azimuth zero reader’s handwheel or observer’s azimuth handwheel is turned? A. The control unit is turned in azimuth and the azimuth distant electric control transmitter is driven in azimuth. This causes the searchlight also to be moved in azimuth.
Q. What is actuated when the elevation zero reader’s handwheel or observer’s elevation handwheel is turned? A. The binocular mount is moved in elevation and the elevation distant electric control transmitter is driven in elevation. This causes the searchlight to be elevated or depressed.
Q. Is there a means of signaling at the control station? A. Yes. There is a push button on the control station which operates a buzzer on the searchlight. On the M1941 control station there is a buzzer which is operated by a push button at the sound locator.
Q. What is the color of the control cable plugs and receptacles? A. Red.
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 34-37
Q. What is the minimum distance that the control station should be placed from the searchlight ? A. 50 feet.
35. Maintenance of General Electric M1940 control stations.—Q. How should the control station be cleaned? A.
(1) The azimuth ring gear and pinion should be cleaned monthly by means of a brush dipped in gasoline. Do not lubricate this gear of pinion, since it would tend to accumulate dirt and dust.
(2) The brush-holder and rings should be cleaned with alcohol every 6 months. They should be kept clean by wiping from time to time.
(3) All electrical contacts should be clean and polished. Never allow oil or grease to accumulate on the insulation.
Q. How should the control station be lubricated? A. Most of the bearings are sealed in oil at the factory. However, when the cover is removed for cleaning, inspect the teeth of the gears and bearings and, if necessary, apply a small quantity of grease to the gears and a few drops of light machine oil to the bearings.
Section IV
SOUND LOCATOR APPARATUS
Paragraph
General_______________________________________________________________ 36
Operation of Ml series sound locators_________________________________ 37
Maintenance of Ml series sound locators_______________________________ 38
Operation of M2 sound locator_________________________________________ 39
Maintenance of M2 sound locator_______________________________________ 40
36. General.—What faculty of an individual enables one to determine the direction from which a sound is coming? A. Binaural sense. It is a faculty of the auditory system.
Q. Are the horns pointed at the true source of the sound? A. No. The horns point at the apparent source of the sound due to the fact that sound travels in air at a speed of 1,100 feet per second, and consequently takes an appreciable time to arrive at the sound locator. During this sound lag time the airplane is traveling. The direction to the apparent source of sound is then corrected by the sound lag corrections (plus wind and parallax) in order to point the searchlight at the true source of sound.
37. Operation of the Ml series sound locators.—Q. How are the horns of an Ml series locator put in their operating position? A. Remove horns from the traveling position supports by releasing the horn locking frame pins. Then clamp horns into place on the horn support by means of the double hooks and hand clamp screws. Be sure the numbers on the horns and supports correspond.
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Q. How is the locator chassis leveled? A.
(1) Unlock turntable by loosening the three locking screws.
(2) Lower four leveling jacks, then by means of these jacks raise the trailer chassis until the four wheels are free to turn.
(3) Move turntable so the level bubbles point over diagonal wheels. Adjust the jacks until the two level bubbles located on the turntable show that the sound locator is level. After leveling, check by turning the locator through 180°. (See fig. 19.)
Q. How is the sound locator oriented in azimuth? A. With the aid of the open sights on the lower elevation horn, orient the sound locators with respect to the searchlight. Then set the azimuth on the acoustic corrector with all correction scales set to zero, to zero degrees (on M1A1 to M1A4, inch), or to zero mils (on M1A5 to M1A8, incl.).
Q. How is the sound locator oriented in elevation? A. Set the sound locator horns to zero elevation. Then set the acoustic corrector to zero degrees (or zero mils).
Q. How is the sound locator operated? A. Each listener seats himself at his control handwheel, adjusts his helmet, and is ready for action. The horns are then placed in the general direction from which the sound is expected (from information given by outpost listeners), or a systematic search is made for possible attacks by enemy airplanes. As soon as a sound is picked up, both operators center on the sound so that it appears to come from directly in front or directly in the rear of the listener’s head (the direction is sensed as front or rear by different listeners), and when this is done the sound locator will be pointed at the apparent source of sound.
Q. How is the Ml or M1A1 acoustic corrector operated? A. The chief of section announces the altitude in feet, which is set in by the elevation acoustic corrector operator. As the listeners track the target, the azimuth acoustic corrector operator reads the time on the sound lag cylinder which is graduated in seconds; if it is 4.2 seconds, he calls “four-point-two,” at which time both corrector operators push their prediction knobs in. At the end of 4.2 seconds (measured by a stop watch) the chief of section gives the command take, at which time the corrector operators release their prediction knobs. The angles indicated on the prediction scales by the prediction pointers are the sound lag angles and are matched by causing the follow up pointers to agree with the prediction operating pointers. This corrects the apparent source data to the true source and is sent by the data transmitters to the searchlight. (Arbitrary corrections must
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GUNNERS’’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 37-38 be set in on the arbitrary correction scales to correct for wind and parallax.) (See fig. 20.)
Q. How is the M2 acoustic corrector operated? A. The chief of section directs the duties of the corrector operator. This acoustic corrector uses a motor (a switch on the acoustic corrector must be turned to the “on” position) which operates automatically the mechanisms which measure azimuth and vertical angular travel during the sound lag time. Altitude in feet is set in by the operator on the altitude scale. As the sound locator tracks the target, the operator alternately matches the pointers of the lateral and vertical rate dials by rotating the corresponding handwheels. The matching of pointers must be done within the 4-second period when the inner pointers are at rest. (See fig. 21.)
38. Maintenance of Ml series sound locators.—Q. If the locator is to be left assembled after use, should the horns be elevated or depressed? A. The horns should be depressed as far as possible in order to prevent rain from entering them.
Q. How often should the horn mount be lubricated? A. Each day before operating the locator. Alemite fittings are provided. Use medium lubricating oil (SAE No. 30) for summer operation and light lubricating oil (SAE No. 20) for winter operation. An oil gun is provided for this purpose. These alemite fittings are located as
follows:
Azimuth handwheel shaft and gear housing------------------ 4
Elevation handwheel shaft and gear housing_______________ 4
Traversing worm housing---------------------------------- 6
Elevation shaft housing (horizontal)--------------------- 9
Elevation worm segment housing--------------------------- 5
Horn journal (left)______________________________________ 1
Horn journal (right)------------------------------------- 2
Turntable________________________________________________ 1
Gear housings (below platform)--------------------------- 7
Q. How often should the trailer be lubricated? A. Every 500 miles. Alemite fittings are provided. Use medium lubricating grease (SAE No. 160) for summer operation and light lubricating grease (SAE No. 90) for winter operation. A grease gun is provided for this purpose.
Q. How often should the acoustic corrector be lubricated? A. The acoustic correctors require no maintenance in the field. Every 6 months the covering plates should be removed and the corrector lubricated. On the cam of the M2 corrector use petrolatum (U. S. Army Spec. No. 2-67). For the gearing and shafting use grade 2 clock oil (U. S. Army Spec. No. 2-47 A).
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39. Operation of M2 sound locator.—Q. Describe the assembling of the M2 sound locator for field operation. A. Place the platform at the position indicated by the chief of section, and adjust until the platform is approximately level. Place the column on the platform and bolt it in place. Place the corrector assembly on the column, first dropping the cable receptacle through the inside of the column. Bolt the corrector assembly to the column and fasten the cable receptacle to its bracket under the platform. Remove the transportation bracket. Elevate the elevation mechanism to 90° and clamp tightly by means of
16. Corrector assembly.
17. Cable plug (female).
18. Column.
19. Platform.
20. Transportation bracket.
29. Azimuth handwheel clamp knob.
Figure 31.—Placing corrector assembly on column.
the elevation clamp. Bolt the single horn assembly in place, then the two-horn assembly. The horns are handled more easily if the canvas covers are removed after horns are assembled. Mount the pantograph on the corrector, screwing it on by means of the pantograph screw knob. Level the sound locator exactly, using the wrench provided to adjust the jacks. Check the level bubble through 180° traverse of the sound locator to insure correct leveling. Connect the blue cable plug to the blue receptacle.
Q. How is the M2 sound locator oriented? A.
(1) Azimuth.— (u) Set target speed to zero.
(Z>) Set parallax offset scale to zero.
(c) Loosen azimuth clamp knob and point sound locator at the orienting point (searchlight or distant point), using the corrector sight
84
16-^29 20
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 39
and getting the image of the pantograph pointer and the orienting point to coincide on the cross lines of the mirror. Be careful not to disturb the corrector handle until completion of orienting and synchronizing in azimuth.
(tZ) Tighten azimuth clamp to hold sound locator in position.
16. Corrector assembly.
21. Azimuth horn.
Figure 32.—Attaching azimuth horn to corrector assembly.
21. Azimuth horn. 22. Common (azimuth elevation) horn.
Figure 33.-;-Attaching elevation and common horn unit to corrector assembly.
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16
21
■22
21.
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(e) Set sound locator scale to zero by loosening the scale and turning it until zero on the scale is under the index pointer.
(/) Push down on declutching gear and rotate parallax cam so that the arrow points at the searchlight. Then remesh gearing.
(2) Elevation.— (a) Lock sound locator at zero elevation by means of the clamp lock.
(&) With zero speed and parallax settings, center pantograph pointer on the cross lines of the mirror. Be careful not to move the corrector handle thereafter until completion of orienting and synchronizing in elevation.
21. Azimuth horn. 24. Elevation listener.
22. Common (azimuth elevation) horn. 25. Azimuth listener.
23. Corrector operator. 26. Elevation horn.
Figure 34.—Sound locator M2 in operating position.
Caution: Even when the sound locator and the searchlight are at different levels, the foregoing elevation adjustment is not to be disturbed. This results in sighting on a vertical line through the orienting point instead of directly on the orienting point.
Q. How is the M2 sound locator operated? A. Set in the target’s air speed and the parallax offset. This information is given by the chief of section. The corrector operator then keeps the pantograph pointer centered on the cross lines of the mirror, using the corrector handle to accomplish this. The listeners track the sound and should do this as smoothly and steadily as possible. Any sudden movement of the horns causes the pantograph pointer to move erratically. The
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,21 23y24 22 25
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 39-40 corrector operator must avoid any sudden change when he is centering the pantograph pointer because it will affect the data sent to the control station.
40. Maintenance of M2 sound locator.—(h Who are authorized to make parts replacement on the M2 sound locator ? A. Only qualified ordnance personnel are authorized to make parts replacement on the M2 sound locator.
Q. How often should the metal mirror be cleaned? A. Not any oftener than is necessary. If the mirror becomes greasy it may be cleaned with soft cotton moistened with alcohol. If the mirror becomes exceptionally dirty or greasy, the surface may be cleaned with a mixture of 3 ounces of precipitated chalk and 8 ounces of a good grade of denatured alcohol.
Q. How often should the slip rings be inspected ? A. Monthly. If dirty, clean with a soft cloth moistened with carbon tetrachloride. Use only a clean cloth.
Q. How is the rubber guard on the open sight cleaned? A. Remove it and wash in warm water, then dust it with french chalk to preserve it.
Q. Should water be allowed to get in the horns? A. No. Water, dirt, or other foreign matter should be kept out of the horns.
Q. What parts of the sound locator should be lubricated? A. The three red plugs on the sight assembly should be lubricated, using a light instrument oil. In addition to the chain drives inside, the locator should be greased with Andok C grease, or, if this is not available, use a good grade of vaseline. To get at the chains remove the cover plate on the corrector.
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Chapter 5
USE AND CARE OF TELEPHONES
Paragraph
Sending, receiving, and recording messages______________________________________ 41
Laying wire, making connections, and tests_______________________________________ 42
41. Sending*, receiving, and recording messages.—Q. For the best results, where should the telephone transmitter be placed with respect to the mouth? A. Not more than 1 inch from the mouth but not touching it.
Q. How should words be pronounced over the telephone? A. Use a moderate tone of voice. Speak slowly and distinctly without slurring any words or syllables. Avoid using words which are difficult to pronounce or with meanings not generally known. When necessary to repeat, make the pronunciation more distinct but never shout or raise the pitch of the voice.
Q. How are numerals sent? A. Singly. Thus, 4,370 is sent “four, three, seven, zero.” Zero is never pronounced “O.” A numeral involving a decimal, like 246.34, is sent thus: “two, four, six, point, three, four.” An exact hundred, such as 200, is sent: “two hundred”; 4,500, “four five hundred.” Even thousands are sent in the same manner, for example, 4,000 is “four thousand.”
Q. What is the procedure when the receiver repeats the message back to the sender? A. Listen carefully to the message. If any part of the message is incorrectly repeated, call “error” and repeat that portion of the message. When the message has been correctly repeated back to the sender, the sender should call “check.”
Q. What is the procedure if the sender discovers that he has incorrectly sent part of a message? A. He immediately calls “error” and identifies the portion of the message in error. He then gives the correct message. With short messages it is best for the sender to repeat the entire message.
Q. How are numerals pronounced? A.
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Numeral Pronounced Principal sounds
0 ZERO Long 0.
1 WUN Strong W and N.
2 TOO Strong T and long 00.
3 THUR-REE Slightly rolling R and long EE.
4 FO-WER Long 0, strong W and final R.
5 FI-IV I changing from long to short and long V.
6 SIKS Strong S and KS.
7 SEV-VEN Strong S and V, and well-sounded VEN.
8 ATE Long A and strong T.
9 NI-YEN Strong N, long I, and well-sounded YEN
Q. What is meant by the phonetic alphabet? A. Certain letters of the alphabet have similar sounds and are often confused in telephone conversations. To avoid this difficulty, the following pronunciation of letters over the telephone is prescribed :
Letter Spoken as Letter Spoken as Letter Spoken as
A Affirm J Jig s Sail
B Baker K King T Tare
C Cast L Love U Unit
D Dog M Mike V Victor
E Easy N Negat w William
F Fox 0 Option X X-ray
G George P Prep Y Yoke
H Hypo Q Queen Z Zed
I Inter R Roger
The words of the phonetic alphabet are used in place of the letters they represent just as in spelling a word. Expressions such as “A as in Affirm” or “A for Affirm” are not used. For example, in transmitting the words “Barts Church” the word “Barts” is apt to be misunderstood. The phonetic spelling is as follows: “Barts, Baker-Affirm-Roger-Tare-Sail.” The phonetic alphabet is also used in the transmission by telephone of coded messages. For example, the code group XISV is transmitted as “X-ray-Inter-Sail-Victor.”
Q. Give some pointers which will increase the efficiency of receiving messages. A.
(1) Keep the mind on the message; a person cannot receive correctly when he is thinking of something else.
(2) Keep the receiver close against the ear.
(3) Do not interrupt the sender except in cases where not to do so would be of serious disadvantage to the correct reception of the message.
(4) Repeat all messages received. Where messages are long, repeat each sentence as it is sent. When any part of a message is not
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understood, call “Repeat,” and continue to have the message transmitted until it is understood.
Q. How is the telephone answered when it rings? A.
(1) Give the official designation or name of the station.
(2) Give the official designation of the person answering.
Q- What is a flash message? A. A message used to indicate the approach of aerial targets. The indication of the target is preceded by the word “flash” repeated three times, and the report is given twice without waiting for an acknowledgment.
Q. Do flash messages follow a particular form? A. Yes. they must follow a form and no unnecessary words should be used.
Q. What information is contained in a flash message? A.
(Front)
FORM FOR FLASH MESSAGE
(AAAIS)
Organization_______________________
Serial No-----------Date------------------------How sent______________________
Time sent___________To________________________
Observation post 1 Number of airplanes 2 Type of airplanes 3 Time seen or heard 4 Altitude 5 Sector in which flying 6 Direction of flight 7
OP One Two Three Several Many Heavy bombardment. Observation Pursuit Light bombardment. Airplane — Very low. Low Medium High — North. NE. East. SE. South, sw. West NW.
Note.—Very low—below 500 yards; low—500 to 2,000 yards: medium—2,000 to 4,000 yards; high—above 4,000 yards.
Both sender and receiver check ofl items where possible and save time.
Q. How are altitudes classified? A. High—above 4,000 yards; medium—2.000 to 4,000 yards; low—500 to 2,000 yards; very low— below 500 yards.
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 41-42
Q. What record is made of a flash message? A. The sender of the message, the operators who transmit it, and the units which receive it, usually record the message by checking the proper words and filling any appropriate blank spaces on a message form.
42. Laying wire, making connections, and tests.—Q. What common types of wire are used in field installations? A. Two types, both twisted pair—W-110 and W-110B.
Q. Describe each type. A. Type W-110 wire has rubber compound insulation covered with weatherproof braid. There are 7 strands, 5 steel and 2 copper. Its weight is 132 pounds to the mile. Resistance is 130 ohms per mile.
Type W-110B is similar to W-110 but has 4 steel and 3 copper strands. Its weight is 132 pounds to the mile. Resistance is 95 ohms per mile. (The candidate should be able to identify either type of wire by looking at it. Arrange a pile of short pieces of different types of wire and let the candidate make his own selection.)
Q. What means are provided for laying wire? A. The wire is carried or laid by any one of the following means, depending upon the conditions of the roads, terrain, and traffic, and character of hostile fire: motor trucks; especially constructed horse and motor-drawn carts and reels; reel carts, hand-drawn or towed behind communication carts; breast reels; spools or coils carried by hand. If issued on wooden spools, wire may be laid by inserting an iron bar through the spool and paying off from it, or the wire may be rewound onto a spool of special design provided for the purpose.
Q. What is the present standard reel? A. The reel unit RL-31.
Q. Describe the reel unit RL-31. A. It is a portable wire-laying and recovery device. It may be used in any one of several ways as follows:
(1) Carried litter fashion between two men.
(2) Pushed or dragged along the ground by one man, wheelbarrow fashion, the reel rims acting as wheels.
(3) Mounted inside or on the extended tail gate of any vehicle which provides the required space. Foot fittings are provided for mounting.
(4) Set up on the ground for unreeling or reeling in the wire.
(5) Mounted outside any vehicle by attachment to the outside of the tail gate.
The unit has a removable brake which may be mounted to either end of the axle. Wire is reeled in by means of a crank which may be placed on the end of the axle.
<2- What is the capacity of the reel unit RL-31? A. One 1-mile reel (type DR—5) or one or two ^-mile reels (type DR-4) of wire W-110 or W-110B.
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Q. In laying wire should the lines be pulled as tightly as possible or laid loosely? A. The lines should be laid loosely in order that the wire may lie flat on the ground, so as to provide sufficient slack for repairing breaks. At suitable intervals, lines should be attached to objects such as trees or posts in order to leave sufficient slack, and to prevent the wire from being pulled into traffic lanes.
Q. How should a traffic lane be crossed in laying wire? A. Where possible the lines should “cross roads” through the culverts. The wires are passed through the culvert and tied up at the entrance and exit to prevent immersion in the water. When it is
Figure 35.—Reel unit RL-31 with reel DR-5.
necessary to carry the wires overhead they should clear the crown of the road by 14 feet. When a line crosses a road between poles or other vertical supports, the wires should be tied at the base and top of the support on each side of the road. The strain which occurs along the line is met by the tie at the base. If neither of the above methods can be used, the line wires should be buried in a trench, crossing the road at right angles. The wires must be laid snug and well secured at both ends of the trench to prevent their being pulled out.
Q. In laying the wire, at what intervals should it be tested? A. It should be tested just after making each splice through the splice, when laying wire in the field. In the case of wire on a reel, a test should be made before the reel is taken out of storage.
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 42
Q Given two pieces of field wire, describe and illustrate how to make a standard field wire splice. A. To obtain a uniform stagger in making the splice, measure back one plier’s length (about 6 inches) from the end of one conductor and cut it at this point. Cut one wire of the other pair in the same manner. Crush the insulation on each conductor, starting at about 6 inches from the end and extending back to 2 inches from the end. Use the heel of the pliers for crush-
Figure 37.—Tying square knot.
ing. Score or ring the crushed insulation at a point about ^2 inch from where the crushing began, with the cutting edge of pliers. Using the pliers, skin the crushed insulation off each conductor, being careful not to damage the strands. Clean the strands with the back of the screw driver blade of the electrician’s knife. Now tie the long and short conductors together, using a square knot so that the knot occurs about 14 inch from the insulation. Strip the weatherproof braid from the insulation about 14 inch on each side
93
TL-I7I7
Figure 36.—Wires skinned and ready for square knots.
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of the knot. Insert a 6- to 8-inch piece of 19-gage bare copper seizing wire in the knot and pull the knot tight. Bend the seizing wire at the middle and make 2 or 3 turns on either side of the knot to bind the ends of the knot. Cut the free ends of the conductors flush with end of insulation. Wrap the seizing wire to left and right of the knot until 2 turns are taken over the insulation. Cut off the excess
TL-1725
Figure 40.—Splice on one conductor after seizing is completed.
Figure 41.—Splice ready for taping.
wire and press ends of seizing wire into the insulation. Apply 2 layers of rubber tape followed by 2 layers of friction tape.
Q. When joints cannot be taped, what should be done to prevent short circuits and grounds? A. The joints should be staggered and raised off the ground.
Q. What telephones are furnished for field use? A. Signal Corps field telephones EE-5, EE-8, and EE-8A.
94
Z TL-/7/O
Figure 38.—Seizing wire inserted through knot.
Cut tail flush with rubber insulation
TLU720
Figure 39.—Wrapping seizing wire.
Grubber DS OD rUbboD
TL-I72I
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 42
Q. How are these telephones classified, i. e., as local or common battery types? A. EE-8, either local or common battery; EE-8 A, either local or common battery; EE-5, local battery only.
Figure 42.—Applying rubber tape.
Figure 43.—Applying friction tape.
Q. Name the principal circuits of a local battery telephone. A. The primary circuit, which consists of the transmitter, battery, and primary winding of the induction coil. The secondary circuit, which
Battery
Leather Case^
Leather F/ap
Line Termina/s
Carrying Strap
Bxternat Battery Term in a is
Battery Compart--ment
Generator Crank
Handset
Handset Cbrd
Figure 44.—Field telephone EE-5.
consists of the receiver, condenser, and secondary of the induction coil. The signaling circuit, which consists of the generator and ringer. These circuits are basic in all local battery telephones. Certain tele-
95
Rubber tape-Friction tape
TL -1723
TL -1722
L
G
TL-740
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42 COAST ARTILLERY CORPS
phones, such as the EE-8 and EE-8A, will have additional circuits, but in any case these additional circuits supplement the above basic circuits.
Q. How is the signaling circuit connected? A. The circuits of both the generator and the ringer are bridged in parallel across the line terminals.
Q. Does the battery current flow through the signaling circuit? A. No. rhe circuit through the generator is always open except when the crank is turned. A condenser in the ringer circuit prevents the battery current from flowing through the ringer.
Q. Does the current from the generator flow through the receiver and transmitter? A. The hand-set switch must be operated in order to complete the circuit through the transmitter. Hence, the generator current will not ordinarily flow through the transmitter. The re-
Figure 45.—Circuit diagram, EE—5 telephone (modified).
ceiver is always connected across the line, so that generator current could flow through it. However, the resistance of the receiver circuit to low frequency currents is very high. The generator produces alternating current at 20 cycles or less per second. Hence, very little of the generator current will go through the receiver circuit.
Q. How are the batteries installed in the EE-8 and EE-8A telephones? A. Remove the hand-set from the carrying compartment. Place two batteries BA-30 in the battery compartment (see fig. 44), being sure that the bottoms of the batteries rest on the springs and that the tops of the batteries rest against the contacts at the top of the compartment.
Q. How is the battery installed in the EE-5 telephone? A. One battery BA-9 (4^ volts) is inserted in a spring clip just below the top of the frame (see fig. 44). The battery is covered by the leather flap formed by one side of the case. Two screws which hold this flap to the frame must be removed to insert the battery, after which the screws should be replaced.
Q. How is the station opened when using an EE-8 or EE-8A telephone? A. Open the case and remove the hand-set from the carrying
96
Rec.
S
T
B
G
0
•R
L
m
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 42
compartment. Place the batteries in the battery compartment. Connect the ends of the line to the terminals marked LI and L2. With a screw driver turn the screw switch to the proper position, depending on whether the telephone is to be operated by local battery or by common battery. There are about iy2 turns of the screw switch between the local battery and common battery positions. If using local battery, call the switchboard, using the generator. If using common battery, removal of the hand set from its position on the lever switch will call the switchboard. Report the designation of the
Ringer MC-131
Wire screw
Lever
Coi/ C-/58 (Holding)
Coi7 C -105 (Induction)
Battery compartment
Generator GN-38
Screw switch
Terminals for handset cord
Binding posts
TM-144
■145 A
Capacitor CA-355
Figure 46.—Field telephone EE—8 with side plates removed.
station and request a ring back. If using common battery it will be necessary to replace the hand set on the lever switch before the switchboard can ring back.
Q. How is the station opened when using an EE-5 telephone? A. Open the cover of the telephone. Remove the crank from the clamp on top and screw it on the magneto shaft which extends out of the side of the case. Remove the hand set from the carrying compartment. Connect the ends of the line to the terminals marked L and G. Call the switchboard by turning the crank. Report the designation of the station and request a ring back.
Q. How is the station closed? A. Report the fact of closing to the switchboard. Disconnect the line from the terminals. With the EE-5 remove the crank and place it in its carrying position. If the telephone
422589°—42---7
97
■Screw
=» eye
Jack^
clamping
TL- i690A
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is not going to be used again liwmediately, remove the battery or batteries. Wrap the cord about the hand set and replace the hand set in the carrying compartment. If the batteries were left in the telephone, be sure that the cord does not operate the hand-set switch.
Q. Demonstrate hooking up two telephones to a length of wire and establish communication. (Local battery only.) A. (Practical demonstration proved by actual communication.)
Q. Is it necessary to operate the hand-set switch in order to listen? A. No, and furthermore the operation of the hand-set switch when listening only is bad practice as it exhausts the battery rapidly.
Q. How may the battery in a local battery telephone be tested? A. If the battery terminals are touched to the tongue, there should be a salty taste noted. Another test is to blow lightly into the transmitter while holding the transmitter switch closed. A distinct sound should be heard in the receiver. In this test the line should be disconnected from the telephone.
Q. When should a telephone be tested ? A. Always before it is taken out for service. Thereafter the tests are made periodically as prescribed. The fact that circuits are in constant use is indicative that
98
INDUCTION COIL
LI
GEN. SWITCH
COMMON BATTERY HOLDING COIL"""
RINGER
2
I
2
bat—
3 V
/LEVER "SWITCH
3
LB CB
GENERATOR
2 ME
\SCREW SWITCH
R
L2
2
.5 MF.
3.
4
>4
.3 MF.
CAPACITOR
MADE BY
(NAME OF CONTRACTOR)
(CITY) (STATE)
ORDER NO.
JACKS
T.& BAT. +
TRANS. (J ^SWITCH
REC
TL-1QS6
Figure 47.—Circuit diagram, EE—8 telephone.
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GUNNERS’’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 42 they are operating satisfactorily. A telephone which is ordinarily very busy and which suddenly becomes quiet should be tested at the earliest opportunity. Communication should never be interrupted to make a routine test.
Q. Name the different types of field switchboards. A. BD-14, BD-71, BD-72, BD-9, and BD-11. All types except the BD-14 are mono-cord switchboards.
SCL-3
Figure 48.—BD—72 switchboard, front view. open.
Q. Describe the BD-71 and BD-72 switchboards. A. The switchboard is inclosed in a plywood case mounted on four collapsible steel legs. The unit includes switchboard units, cords, operator's telephone with head and chest sets, lights, switches, and night alarm, batteries BA-30, repeating coils, and terminal strips. Outside of the fact that the BD-71 has only 6-line capacity compared to the 12-line capacity of the BD-72, there is no practical difference between the two switchboards.
Q. Describe the BD-9 and BD-11 switchboards. A. The BD-9 has a capacity of 4 lines and the BD-11 of 12 lines. The unit consists of a frame on which the individual drops are mounted. Operator’s telephone, terminal strips, repeating coils, and similar items are all separate from the switchboard. A fiber carrying case is provided for the protection of the switchboard when not in use.
Q. Demonstrate hooking up a telephone, a length of wire, and a BD-71 or BD-72 switchboard. A. (Practical demonstration proved by actual functioning.)
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Figure 50.—Switchboard BD-71 set up for operation.
100
SCL-4
Figure 49.—BD—72 switchboard, rear view, open.
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 42
Q. Demonstrate hooking up an operator’s telephone, battery, night alarm, and one line with telephone connected to a BD-9 or BD-11 switchboard. A. (Practical demonstration proved by actual functioning.)
Q. What is the purpose of the ground wire? A. Protection against lightning. An air spark gap is incorporated in each unit. The ground wire grounds one side of the lightning arrester.
Q. Is it desirable for the operator to keep his telephone connected to two lines which are in use? A. No. The extra load which his telephone puts on the lines will impair transmission between the two telephones which are in use.
Q. How does the switchboard operator know when someone is calling the switchboard? A. Ringing current on the calling line operates the shutter coil and allows the shutter to drop to the horizontal position. If the night alarm switch is closed, the shutter cam will close the night alarm circuit and cause the alarm to operate as long as the shutter is down.
Q. What does the operator do when he sees the shutter drop on one of the units? A.
101
Spare Pair
Strap) Screwed to Switchboard
TL639
Figure 51.—Switchboard BD—11.
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(1) If using a BD-71 or BD-72 switchboard, the operator depresses the ring-talk key on the unit calling. He identifies the switchboard by name and determines the number desired by the party calling. He then restores the calling party’s key, and rings the called party by raising the ring-talk key on that unit and turning the generator handle rapidly several times. He next depresses the called party’s ring-talk
Figure 52.— Switchboard BD—9 set up for operation.
key to the talk position and inserts the calling party’s plug in the jack of the called party. While the ring-talk key is in the talk position the operator’s telephone is bridged across the connection, allowing him to supervise the call. The calling party’s shutter is left in the dropped position until the call has been completed. A shutter down indicates that the call has not been completed and that further supervision of the connection is necessary.
(2) If using the BD-9 or BD-11, the operator inserts his plug in the calling party’s jack, identifies the switchboard by name, and determines the number desired by the calling party. He places the operator’s plug in the jack of the called party and turns the generator of the operator’s telephone. He then inserts the called party’s plug in the
102
To Ground-.
Rod^d
Operator's Telephone Securely Attached to Support -s
N/qhf A/a rm.
TRAFFIC DIAGRAM
TELEPHONE DIRECTORY
Spare Jtto/r
'Ntqhf A /arm Battery Off Ground
Ooh/e to
\ Term Ina/
GroundRod-Out ofThe
Way of Opera for
TL-556
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 42 jack of the calling party. The operator leaves his plug in the jack until he finishes supervising the call at which time he removes his plug and restores the shutter on the calling party’s unit.
Q. Why must the switchboard be upright when in operation? A. The shutter drops by gravity. If the board is not upright or inclined slightly forward, the shutter cannot drop.
Q. What are some of the troubles which may occur in a telephone system, and what are the tests and remedies? A. See table at end of this chapter.
Q. Describe and demonstrate how to test a telephone. A. Install the battery. Holding the receiver to the ear, blow steadily into the transmitter while alternately operating and releasing the hand-set switch. The blowing should be very audible as long as the hand-set switch is at the on position. Holding the receiver to the ear, operate the generator. The handle should be easy to turn and the impulses should be heard in the receiver. The ringer should not operate. Short circuit LI and L2 and turn the generator again. It should now be hard to turn as though a drag had been placed on it, the impulses should be heard in the receiver, and the ringer should not operate. Remove the short. Connect the telephone to another telephone known to be serviceable. Turn the generator on the other telephone. The ringer of the telephone being tested should operate.
Q. What repairs are telephone operators authorized to make? A. With the exception of changing batteries, cleaning contacts which are accessible without taking down the telephone, and changing the head set or hand set, the operator is not authorized to make any repairs.
Q. How can most telephone troubles be avoided? A. Most of the troubles in telephone communication can be avoided if telephones are carefully used and cared for and are examined and tested before being taken out for service each day. In addition, the batteries must be in good condition, and care must be taken to see that all joints make good contact, including all splices in the lines.
Trouble Possible cause Tests and remedies
Home station cannot ring distant station. (1) Improper line connection at telephone. (2) Open circuit in line. (3) Generator out of order. (1) Examine connections. Clean and tighten if necessary. (2) Examine line for breaks. (3) Test the telephone at the home station. Repair or replace, as may be necessary.
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Trouble
Possible cause
Tests and remedies
Distant station cannot ring home station.
Home station can signal distant station bnt cannot hear distant station talk.
Distant station can signal home station but cannot hear home station talk.
(4) Receiving circuit open, or damaged receiver.
(5) Ringer at the distant station not functioning.
(6) Short circuit in line.
See above.
(1) Operator at distant station not operating the h a n d - s e t switch.
(2) Battery at the distant station dead.
(3) Battery contacts corroded.
(4) Broken transmitter cord at distant station.
(5) Hand-set switch at distant station does I not make contact.
(6) Carbon in trans- i mitter at distant station packed.
(7) Broken receiver cord at home station.
See above.
(4) Test the telephone at the distant station. Repair or replace, as may be necessary.
(5) Test the telephone at the distant station. Repair or replace, as may be .necessary,
(6) A shorted line is usually distinguished by the generator turning hard. Examine the connections and the line. Remove the short when discovered.
See above.
(1) Operate the hand-set switch
properly.
(2) Test the battery. If weak or exhausted, replace.
(3) Examine contacts and battery terminals. Clean if necessary .
(4) Disconnect hand set and touch battery terminals with receiver and transmitter cords, being sure that the hand-set switch is operated at the same time. A click should be heard in the receiver if the transmitter cord is all right. Replace cord if necessary.
(5) Test as in (4) above. Clean and adjust if necessary.
(6) Usually distinguishable by sizzling or crackling noise in receiver. Replace telephone.
(7) Disconnect hand set. Touch receiver and common cords to terminals of a battery simultaneously. If a click is heard the receiver circuit is all right. Replace cord if necessary.
See above.
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 42
Trouble
Possible cause
Tests and remedies
Station cannot signal switchboard.
(1) Fuse on switchboard burned out (BD-9, BD-11 only).
(2) Shutter stuck on its hinge.
(3) Armature holding shutter is out of adjustment or bent.
Night bell fails to operate when a j shutter drops.
(4) Coil of shutter release magnet burned out.
(1) Battery dead.
(2) Loose or dirty connections.
(3) Bell contacts corroded.
(4) Shutter dropping does not close bell circuit.
(5) Bell coils open.
(1) Examine fuses and replace i if necessary.
(2) Trip shutter by hand. If , the shutter will not drop of its | own accord, clean hinge.
(3) BD-9 or BD-11: Hold tip ■ of red (operator’s) plug against terminals of section being tested.
| Ring operator’s telephone. If the armature vibrates but does not release the shutter, adjust armature until it does.
BD-71 or BD-72: Put the ■ plug of an unused circuit across the terminals of the unit being tested. Put ring-talk key to ring I position and operate the generator. If the armature vibrates but does not release the shutter, adjust armature until it does.
(4) Test as in (3) above. If the armature does not vibrate, the coil is probably burned out. Replace entire unit.
(1) Test battery and replace if necessary.
(2) Check through all connections. Clean and tighten where i necessary.»
(3) Examine bell. Clean the contacts if necessary.
(4) Adjust the contacts so the I circuit will be completed.
(5) Connect a receiver in series j with a battery and the bell coils. When the circuit is closed, there ' should be a click in the receiver if coils are ah right. Replace if
necessary.
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Chapter 6
MOTOR TRANSPORTATION
Paragraph
Nomenclature of major parts of motor vehicles____________________________ 43
Practical operation of motor vehicles to include driving and fueling_____ 44
Duties of driver in care, service, repair, and maintenance of motor vehicles_________________________________________________________________ 45
Trouble shooting and minor repairs_______________________________________ 46
Convoy and march rules and discipline______________________________________ 47
Handling trucks under adverse conditions___________________________________ 48
43. Nomenclature of major parts of motor vehicles.—Q. Into what general groups may the parts of any motor vehicle be divided ? A. Power plant, transmission system, control system, chassis, running gear, and body.
Q. Point out the principal parts of the power plant to include the crankcase, cylinders, valves, and various parts pertaining to fuel, carburetion, ignition, lubrication, and cooling systems.
Q. Point out the principal parts of the transmission system to include the clutch, transmission, driveshaft, universal joints, differential. torque arms, and axles.
Q. Point out the principal parts of the control system, chassis, and running gear to include frame, springs, brake drum, brake rods, wheels, steering knuckle, drag link arm, emergency and foot brakes.
Q. Why are instruments installed on the dash? A. For the purpose of indicating and controlling the operation of the engine and vehicle.
Q. What instruments are usually installed? A. Ammeter, oil pressure gage, speedometer, thermometer (engine temperature), choke, light switch, hand throttle, spark control, and ignition switch.
Q. What does the ammeter indicate? A. The amount of current that is being consumed by the ignition and light system of the vehicle from the battery, or the amount of current that the generator is supplying to the battery.
Q. What is the normal operating temperature of a gasoline engine? A. Approximately 180° F.
Q. Where is this temperature taken? A. In the water that surrounds the cylinders and combustion chambers of the engine.
Q. What is the purpose of the oil pressure gage? A. To indicate to the operator the pressure under which the oil is being forced from the oil pump.
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GUNNERS' INSTRUCTION, AA SEARCHLIGHT BATTERIES 43
107
Hydraulic brake
Shock absorbers
Six-Cylinder engine
Gear-shift lever
Independent front suspension
f el tank I-beam, X- type
\ frame
1 j Ci
Sb Q 4! >
•S h £ K
k. s 1 e
Vf Qc Cl
Transmission Steel wheel_
Figure 53.—Modern gasoline-engine-driven passenger car chassis showing its various parts.
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Figure 54.—Typical engine and transmission assembly showing external parts, equipment and accessories.
Figure 55.—Interior view of truck cab showing instruments and controls.
108
zur Cleaner
Spark plug Wires x spark Plugs . To Scaitch
Gear Shift —Lever
^Ignition Coil , ^-Cqlinder head ,Cqlinder Head Gasket ■ Oil Filter —Cqlinder
■L ^ Block/Z
Hahd Drake, (Band
4—-To Batterq
ib
SI—Starting. Motor
1 ■ jcaitch
Carburetor
Upper Water ft Fan Outlet and
f thermostat
W Fan palleq / S?'
(k I Water /0;i
/ B /UxPu / f™er^ k I K / / WJkfcW»°ltaqe('^^=( ■/ _ ]) Tslf Regulator Hf
Ml ■/tKtIeH II । ■ and,Cat Out/M
Breather \ and oil, \ filler Pipe
ntartinq Motor
Transmission Filler Plug
Generators
Fan | belt
Oil pan gasket,
Oil level Baqonet Guage
Impulse) \ ->
Neutruhjcr pi5tribator-
Front Eng. Sapport
Crank. Case-
\ / I,Tt^-Transmission^^t Rear Engine Supports
^Clutch Housing
FUEL GAGE WATER SPEEDOMETER AMMETER VISCO-METER WINDSHIELD IGNITION SWITCH
X TEMPERATURE I / rotator
X GAGE |
THROTTLE
CHOKE'
-serial plate
FIRE EXTfNGUlSHEP
HAND BRAKE LEVER
TRANSFER CASE SHIH WAGRAM
LIGHT CUT-OUT SWITCH
LIGHT SWITCH-
CAB
VENTILATOR
CLUTCH_ P£DAL~~
DIMMER^. SWITCH
BRAKES PEDAL
ACCELERATOR TRANSFER CASE \ TRANSlAlSSiON
PEDAL SHtn l^VER STARTER PEDAL SHIFT LEVER
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 43-44
Q. Does the oil pressure gage indicate that the engine is being lubricated? A. No; it only indicates that the pump is forcing oil some place at the pressure indicated by the gage.
Q. What is the purpose of the choke? A. To restrict the air passage at the inlet of the carburetor, thereby giving a rich mixture for starting and warming up the engine.
Q. What data are usually found on the dash plate? A. Make and model of vehicle, maximum speed, tonnage that the vehicle was designed to carry, engine number, serial number, and date of manufacture.
44. Practical operation of motor vehicles to include driving and fueling.—Q. What are the qualifications for a good driver? A. Good physical condition and common sense.
Q. Define common sense in connection with driving. A. Alertness, judgment, and caution on the road. A good driver will obey all traffic regulations and carry out the rules of good maintenance driving. He will respect the rights of other drivers and of pedestrians.
Q. List a few rules that will help to prevent accidents. A.
(1) Have vehicle under control at all times.
(2) Never exceed the prescribed speed limits.
(3) Obey all traffic regulations and special instructions.
(4) Never depend on what the ether operator or pedestrian may do.
(5) Never operate a vehicle with faulty brakes, steering mechanisms, or lights.
(6) Always use the proper signals.
Q. How should a vehicle be loaded? A. The load should be distributed equally, fore and aft, and to the right and left of the center of gravity of the vehicle. It should be systematically loaded to facilitate delivery. Any load beyond the capacity of the vehicle should be refused. The load should be properly secured. Red flags or lanterns must be attached to all loads protruding beyond the truck body.
Q. What inspections are required to be made by the driver before leaving and after returning to the garage? A.
(1) Oil lever in crankcase.
(2) Water in radiator.
(3) Gasoline supply.
(4) Condition of tires and battery.
(5) Inspection for leaks in cooling and oiling systems.
(6) Mechanical condition of vehicle, especially brakes (steering), lights, and horn. Any faults and unusual noise observed during operation should be reported to dispatcher immediately.
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Q- Give several common faults in driving which are damaging to the vehicle? A.
(1) Racing the engine at any time.
(2) Inadequate use of the gears.
(3) Excessive or improper appliance of the brakes.
(4) Riding, slipping, or quickly engaging the clutch.
(5) Turning front wheel, while standing.
(6) Excessive use of the choke.
(7) Excessive speed in first or second gears.
(8) Continuing to drive with minor maladjustments.
Q. What precautions should the driver take against fire? A.
(1) Never refuel while engine is running.
(2) Be careful not to let the fuel tank overflow, as hot exhaust pipe and manifold can readily ignite the fuel.
(3) Keep old oily rags, waste, and papers from under the seat.
(4) Keep engine clean.
(5) Do not smoke while driving or on the vehicle.
Q. What should be done in case a vehicle catches fire? A. If the vehicle is inside a building, push it out, if possible. Use the fire extinguisher that is carried on every Government vehicle, playing it directly on source of fire. Do not use water on a gasoline or oil fire; it only tends to spread it. If the fire extinguisher is not sufficient to extinguish the fire, use dirt, sand, or mud; in some cases it can be smothered by using such articles of clothing as may be available. If fire should break out in the load of the vehicle, remove load until the source of the fire can be reached.
(?. What precautions are necessary in cold weather? A.
(1) Keep a check on antifreeze solution in radiator.
(2) Watch condition of battery, as it does more work and is less efficient in cold weather.
(3) Never add cold water to an overheated engine.
(4) Never drive fast on slippery roads.
(5) Use chains or tractioneers when necessary.
(6) Keep off soft or partially frozen ground.
Q. How should air brakes be applied? A. The best possible stop will be made when the brakes are applied at the very start as hard as the speed and condition of the road will permit, and then eased off as the speed is reduced, so that at the end of the stop but little pressure remains in the brake chambers. In easing the brakes off, do not “fan” the brake valve (repeatedly releasing and applying the brakes) as this wastes air pressure.
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Q. What inspection of air brakes should be made before starting the vehicle? A. Observe the air pressure gage, showing the pressure stored in the reservoir. It must read 40 pounds or over before the air brakes can develop full effectiveness.
Q. What maintenance must be performed by the driver on an air brake system? A. Drain the reservoir, daily in cold weather and weekly in warm weather, by opening the drain cock on the bottom.
Figure 56.—Typical two-speed transfer ease showing relation to driving and driven units and disengaging feature for front axle.
This allows any water collected in the reservoir to run out. Be sure to close the drain cock after the water has been removed.
Q. What is an auxiliary transmission? A. An over-, under-, and direct-drive gearing used in conjunction with the transmission.
Q. How is an auxiliary transmission operated? A. When operating under ordinary road and load conditions, it is placed in direct-drive position. When operating under difficult road conditions, or over uneven roads or steep grades with capacity loads, it is placed in the under-drive position. When operating over level roads with
111
, BICS W LOW SHOT RAIL
HIGH SPEED DRIVE GEAH-
LOW SPEED DRIVE GEAR-
TO TRWSHISSIOS
• SPEEDOMETER DRIVE pro:? axle tUSBSGACgWT LEV®
OKE OF 10
BEARtkCS USED
TO ®OET AXLE
TO SEAR AXLE
■SPLIKED COLLAR
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44 COAST ARTILLERY CORPS
light loads, it may be placed in the over-drive position to give maximum road speed without excessive engine speed.
Caution: The auxiliary transmission must never be shifted while vehicle is in motion.
Q. What precaution is taken before stopping or turning a corner? A. Signal to drivers of vehicles behind by holding out the arm. Before turning corners or sharp curves, slow down, sound the horn, and be prepared to stop to avoid collisions with other cars which may be hidden from view. The same precautions are taken at street intersections or crossroads which are not clearly visible for some distance in each direction.
Q. Mention the most important rules to be observed on the road. A.
(1) Have vehicle under control at all times.
(2) Always keep a safe distance in rear of vehicle in front so you can stop if that vehicle stops suddenly.
(3) Keep on the right side of the road.
(4) Do not try to pass a car parked or moving on your side of the road if a car is coming in the opposite direction.
(5) Do not try to pass a car on a hill or curve unless you can see the road far enough ahead to assure yourself that no car is coming in the opposite direction.
(6) Sound the horn before passing a car going in the same direction.
(7) Go slowly on sharp curves.
(8) Do not pass street cars taking on or discharging passengers except where safety zones are provided.
(9) Never exceed prescribed speed limits nor the speed limit of your vehicle.
Q. How is a car brought back to the center of the road after beginning to skid on a wet pavement or muddy road? A. When the rear of the car starts to skid, turn the steering wheel in the direction the car is skidding and partially close the throttle. To close the throttle entirely would have the same effect as applying the brakes. Do not apply the brakes. When skidding on a narrow road, it is best to apply more power and steer for the center of the road. This will aggravate the skid for a moment but will bring the car around at an angle with the front wheels in the center of the road. The momentum of the car will cause the rear wheels to climb back onto the road.
Q. Should the gas tank be filled while the engine is running ? Why ? .1. No. Because of the danger of fire.
Q. What precaution should be observed when filling the radiator when engine is very hot ? A. The engine should be stopped and allowed
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to cool off before adding water. If time will not allow this, let the engine run while water is added slowly (preferably warm water).
Q. How should radiator be protected in cold weather?. A. Unless filled with antifreeze solution, the radiator and water jackets should be completely drained, when the vehicle is not in use, and a “drain” sign hung on the radiator. Sometimes it will be necessary to protect the lower front half of the radiator with tin or cardboard or canvas. The candidate will be required to—
(1) Start the engine of a truck or car.
(2) Start in first gear, shift into second and third gears.
(3) Shift back into second gear.
(4) Stop the vehicle.
(5) Shift into reverse gear and back the vehicle.
(6) Shift into neutral and stop engine.
45. Duties of driver in care, service, repair, and maintenance of motor vehicle.—Q. What defines the duties of the driver?
A. FM 25-10. Technical Manuals of the 10-series, AR 850-15, Circulars 1-10, OQMG, and the motor vehicle manual issued with each vehicle.
Q. How are drivers selected? A. On the basis of their standing in an examination on the course of instruction laid down in FM 25-10.
Q. What are the responsibilities of the driver ? A.
(1) Operation and maintenance of motor vehicles in accordance with instructions.
(2) Care and condition of vehicle, tools, and equipment.
(3) Loads and loading.
(4) Reports and records.
Q. With what should the driver be thoroughly familiar? A.
(1) Fire precautions and fire fighting methods.
(2) Accident prevention.
(3) Purpose of the major units of the motor vehicle.
(4) Motor vehicle controls.
(5) Inspections.
(6) Maintenance.
(7) That part of the motor vehicle manual that pertains to the driver.
Q. How is the vehicle fire extinguisher used? A. By removing it from its bracket, unlocking it, and pumping. The stream of liquid must be directed at the top or to the windy side of the flame since the liquid releases a gas which is heavier than air. Caution: This gas is harmful to breathe.
422589°—42---8
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Q. What may be used to fight a gasoline fire? A. Sand or a special extinguisher of the foam, CO2, or carbon tetrachloride type, but never water.
Q. Where are motor vehicle keys kept when the vehicle is in the garage ? A. They are kept in the vehicles or on a plainly marked board nearby so that vehicles may be moved quickly in case of fire.
Q. May the driver remove gasoline from his fuel tank ? A. No. The regulations forbid the use of gasoline for cleaning purposes. Gasoline for all authorized purposes may be obtained on a regular issue slip.
Q. For what accidents are drivers responsible? A. All accidents that occur to their vehicles while in motion, when parked in an unauthorized place, or when being worked on by themselves.
Q. How may most operational accidents be prevented? A.
(1) By driving carefully and observing traffic regulations.
(2) By the use of an assistant when the driver cannot see where he is moving, as when backing or driving without lights.
Q. What general precautions should be taken by the driver when working on his vehicle? A.
(1) He should not start the engine unless the controls are in neutral.
(2) When working under a truck, he should not depend upon jacks but the vehicle should be firmly blocked.
(3) To lessen the danger of fire he should remove the battery in case of doubt or major repair.
(4) He should work in a well-ventilated place.
(During examination the candidate should be required not only to explain the following motor vehicle units and controls but also to demonstrate their proper use to prevent damage to the motor vehicle.)
Q. What is the proper use of the choke? A. To assist in starting when the engine is cold or the vehicle has been left idle for some time. Excessive use will flood the engine, making starting impossible and interfere with proper lubrication.
Q. What throttle setting should be used for starting? A. This depends upon the vehicle. Most carburetors are designed so that the proper setting for starting is determined by a throttle stop. By stepping on the accelerator a few times before starting, the engine will be primed, and the engine should start when the starter is engaged.
Q. What throttle setting should be used until the engine warms up ? A. A setting corresponding to about 20 mph vehicle speed. The engine should not carry a load during this period.
Q. What is the proper use of the accelerator? A. The accelerator should be depressed slowly. Tramping on the accelerator floods the engine, wastes gasoline, and fouls the spark plugs.
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Q. What precautions must be taken with the ignition switch ? A. It must be left locked, whenever the vehicle is parked, to prevent damage to the coil and battery.
Q. How is the proper spark setting determined? A. If the engine runs with full power without knocking, the spark setting is satisfactory.
Q. How do you select the proper gear? A. A gear is selected that will allow the engine to run without lugging. If the engine cannot reach its governed speed, gears should be shifted. When descending grades, a gear must be selected that will not force the engine to run faster than its governed speed.
Q. What is the proper way to shift gears? A. Bring the engine to full governed speed in each gear as the shift is accomplished.
Q. Can front-wheel drive clutches be used while the vehicle is in motion? A. Yes. Levers must not be forced. In some instances the front wheels may have to be turned to allow shifting dogs to come into line. (Drivers of all vehicles should be required to master these special shifting devices.)
Q. What damage might result from the improper selection of gears? A.
(1) Engine bearings might be damaged or cylinder head gasket blown.
(2) The driver might be forced to shift down two gears and thus delay the convoy.
(3) If on a down grade the truck might run away or the engine may turn up so fast that it will be damaged.
Q. What care must be taken of the clutch? A.
(1) The clutch must not be slipped; gears should be used instead.
(2) When the clutch needs adjustment, a prompt report should be made to the motor sergeant.
(3) The clutch must not be let out suddenly or damage to the whole vehicle will result.
(4) The clutch must be properly lubricated but must not be overlubricated or it will slip.
Q. Explain double-clutching, and for what is it used? A. Doubleclutching is accomplished by engaging the clutch while the transmission hesitates in neutral when the gears are being shifted up or down, then shifting to the next gear in the normal manner. During the hesitation period the foot is removed from the throttle if the shift is from a lower to a higher gear; if from a higher to a lower gear the engine is speeded up to the speed that it should be running in the lower gear selected. Double-clutching is useful in shifting from a lower
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to a higher gear on trucks that are hard to shift. It is useful in changing to a lower gear preparatory to descending a grade. Doubleclutching has its limitations, and the driver must not wait until it is too late to shift. (All drivers should be required to shift from a higher to a lower gear without clashing gears.)
Q. What does the oil gage indicate? A. Oil pressure only. The quantity of oil is indicated by the dip stick. Lack of oil or oil pressure is very serious.
Q. What kind of oil should be added to the crankcase? A. The kind recommended in the instruction manual.
Q. What is the purpose of the handbrake? A. To hold the vehicle in a parked position. In emergency to relieve the foot brake. Caution must be exercised in applying the handbrake because if it is of the propeller shaft type a sudden application may strip the rear end gears and the vehicle will be out of control.
Q. What is the proper way of applying the foot or service brake? A. It must be applied, except in case of emergency, with evenly increasing pressure; as the vehicle comes to a stop the pressure should be progressively reduced to give a smooth stop. Sudden stops are hard on the vehicle and on the brakes and may cause rear end collisions.
Q. How are air brakes used? A. The same as any other type of brake. The habit of fanning air brakes is dangerous.
C- Define first echelon maintenance. A. First echelon maintenance includes all the maintenance functions required to be performed by the driver and his assistant, using only the tools and spare parts on his truck. It is divided into three parts: inspection, preventive maintenance, and repairs.
Q. What inspections are required to be made by the driver? A.
(1) During operation.
(a) Note abnormal readings of dash gages.
(J) Note unusual engine sounds.
(2) At the halt.
(«) Check for fuel, oil, and water leaks.
(&) Check tires, tracks, and traction devices.
( (phi), quadrant elevation; H, altitude; F, fuze range; and R, horizontal range.
Time of flight.—The elapsed time from the instant the projectile leaves the bore of the gun to the instant of impact (burst).
50. Antiaircraft searchlights.
Acoustic corrections.—Corrections to sound locator data for nonstandard atmospheric conditions and sound lag.
Aerial sound ranging.—The process of locating aircraft by means of the sounds emitted.
Arbitrary corrections.—Corrections to sound locator data which are applied to correct for observed errors after all known deviating causes have been corrected for.
Distant electric control.—A system for the control of the pointing of searchlights from a distance. The system consists of the controller at the control station and the necessary motors or receivers at the searchlight.
Sound lag.—The angular difference between the actual (present) position of the target and the apparent position as indicated by sound.
Zero read,er.—A device for indicating when the searchlight is properly pointed on corrected sound locator data.
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Chapter 8
NOMENCLATURE, ACTION, AND MAINTENANCE OF SMALL ARM WITH WHICH ORGANIZATION IS EQUIPPED AND ITS AMMUNITION
Paragraph
Rifle, U. S., caliber .30. M19O3______________________________________________ 51
Rifle, U. 8., caliber .30. Ml_________________________________________________ 52
Pistol, automatic, caliber .45. M1911 and M1911A1----------------------------- 53
51. Rifle, U. S., caliber .30, M1903.—a. Nomenclature and action.—Q. By what other name is the M1903 rifle often called? A. It is popularly referred to as the “Springfield rifle” because it was first made at the Springfield Armory, Springfield. Mass.
Q. Hoav would you classify it according to its method of operation? A. It is a breech-loading bolt action magazine rifle.
Q. What is meant by caliber .30? A. Caliber .30 means that the distance between two directly opposite lands in the barrel, expressed in inches, is 30/100 of an inch.
Q. What are the lands and grooves? A. The lands are the raised portions of the bore and the grooves are the spaces between the lands.
Q. What direction of twist do the lands and grooves in the bore give the bullet? A. A right twist, or clockwise as seen from the breech.
Q. How does this affect the bullet? A. The rotation keeps the bullet from tumbling in its flight, but also causes it to drift slightly to (he right.
Q. In firing, should any allowance be made for drift ? A. No. This is automatically corrected for in the construction of the rear sight leaf.
Q. What ranges can be set on the sight leaf? A. Ranges from 100 to 2,850 yards.
Q. What is the weight of the rifle? A. About 8% pounds.
Q. What is the length of the rifle? A. About 43 inches.
Q. What is the muzzle velocity of the ball cartridge? A. 2,700 feet per second.
Q. What is the muzzle velocity of the guard cartridge? A. 1,200 feet per second.
Q. How many shotscan be fired without reloading? A. The magazine of the rifle will hold five cartridges and one additional cartridge
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may be inserted in the chamber, thus making the maximum capacity of the rifle, for any one loading, six shots.
Q. What is meant by the balance of the rifle and where is it located ? A. As the name implies it is where the rifle balances when held in the hand. It is just below the windage scale and in front of the floor plate.
Q. Point out the following parts:
Barrel. Slide screw.
Front sight. Range scale.
Stacking swivel. Bolt.
Stock. Bolt handle.
Upper band. Floor plate.
Lower band swivel. Sleeve.
(Grasping groove. Firing pin.
Hand guard. Firing pin sleeve.
Rear sight. Striker.
Movable base. Main spring.
Windage screw. Extractor.
Windage scale. Safety lock.
Drift slide. Cut-off.
Slide. Cocking piece.
Ejector.
Magazine.
Floor plate.
Guard.
Trigger.
Lower band.
Butt swivel.
Butt plate.
Bayonet.
Bayonet guard.
Bayonet grip.
Bayonet catch.
Oiler and thong case. Brush and thong.
A. See accompanying figures and the rifle itself.
Q. What does the letter “U” on the lower band mean? A. If the band is taken off it should be put back with the “U” up. as the band is tapered to fit the barrel and stock.
Q. Explain the working of the extractor. A. In loading from the magazine, the hook of the extractor catches in the groove on the cartridge case as the follower pushes it up from the magazine. The hook of the extractor continues to hold the cartridge case against the head of the bolt until the bolt is drawn fully to the rear. When the bolt is rotated and drawn to the rear, the extractor brings the cartridge case back with it.
Q. What does the ejector do? A. When the bolt is almost fully back, the top locking lug strikes the heel of the ejector and throws the point of the ejector suddenly to the right. As the bolt continues to move back, carrying the cartridge case with it, the ejector hits the rear face of the cartridge case and throws it out of the receiver.
Q- When firing, how can you tell when the last cartridge in the magazine has been fired? A. After the last cartridge has been fired and the bolt drawn fully to the rear, the follower rises and holds the bolt open to show that the magazine is empty.
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129
Extractor fixed base-' \ X. Windage screw knob \ Windage screw collar X>lide binding screw
Bolt stoppin
Cut-off spindle. ^^/Z/^^ctor5'0 Drift slide. P\ /Slide cap screw
Sleeve lock spring^ J Extractor collar,_X \ /_^Windage screw
Sear pin ..
Searnose /Bolt stop spring Locking lugs Movable base. Leaf ^Handguard
Safety lock thumb piece, । Safetylockspindle//^Clip slot(2) Receiver .Barrel Firing pin rodx _AZ _ ) XX-X^// XQ'n sPrin9 X // I f
Cockinq piece. X / -VX Firing pin sleeve
Sear notcm^
s 2 Recoi 11 ug Xtock.
^^^^^^^^^^^^/^^n\\X7T^SearspringU\ Vol lowerXX/”—Front guard screw digger |\\\ , , \\xMagazine X^" Front stock screw
p,n^Avfloor plate catch \VMagaZine sprmg^Cartndge ramp screw bushing WX^r^^XXL °°r S V • 'Floor plate -Rear auard screw \ Floor plate pin 1U H
Trigger Guard bow Floor plate spring
Figure 57.—Mechanism of the M1903 rifle.
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Q. Describe the normal open sight. A. The top of the front sight appears to be even with the top of the rear sight slide, and the front sight appears in the middle of the rear sight notch.
IB s
i|rl| v® I
g | §
S « fes g
O Lfbki 8
$911 y . I i fa B D ' ■ T1 bk ftJ |W f
§& iiu i
liBj ■
Q. Describe the normal peep sight. A. The top of the front sight appears to be in the center of the peep.
Q. What is battle sight, and what range is battle sight? A. The sight when the sight leaf is down—range about 547 yards. The’sights are alined as for the normal open sight.
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Q. In firing with battle sight, how high is the trajectory above the line of sight at 300 yards? A. 2% feet.
Q. What preparatory instructions should be held before going on the range? A. The six steps of preparatory instructions are—
(1) Sighting and aiming exercises (with sighting bar and rest).
(2) Position exercises.
(3) Trigger squeeze exercise.
(4) Rapid fire exercises, in all positions.
(5) Instruction in the effect of wind, sight changes, and use of score book.
(6) Examination before going on the range.
Q. What do you mean by the “zero” of a rifle? A. The point at which the rear sight must be set for both elevation and windage for any particular range in order to hit the center of the bull’s-eye on a normal day when there is no wind.
Q. What do you mean by “cant” and what is its effect? A. It is tilting the rifle to the right or left. The effect is to cause the rifle to shoot low and to the side the rifle is tilted.
Q. Where do you focus your eye when aiming a rifle? A. On the target.
Q. In firing at a vertical target what is the rule for correcting your fire in elevation? A. Square the range expressed in hundreds of yards. The result is the number of inches on the target that the next shot will strike above (or below) if the rear sight is raised or lowered 100 yards. Example: When firing at the 200-yard range, raising the rear sight 100 yards will move the next shot 4 inches up on the target.
Q. To shoot to the right (or left), which way would you move the sight? A. To shoot to the right move the movable base of the sight to the right. To shoot to the left move the movable base of the sight to the left.
Q. How much does one point on the windage scale correct for? A. Four inches for every 100 yards of range; so at 300 yards range one point corrects for about 12 inches.
Q. How do you figure the effect of a cross wind? A. Multiply the range in hundreds of yards by velocity of the wind divided by 10 to find the number of quarter points correction necessary. Example: When firing at the 200-yard range, a 10-mile wind calls for y2 point correction.
Q. What is the smallest graduation on the windage scale? A. A point—not a quarter point.
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In what direction do you move the sight to correct for wind effect? A. Always into the wind.
Q. How do you aim when using guard ammunition? A. Use battle sight and aim at the hips.
Q. What are the positions for rifle firing? A. Standing, kneeling, sitting, and prone.
Q. Describe and demonstrate the firing positions. A. For all positions face half right from direction of fire and then take the position. The rifle then makes an angle of 45° with the body and should point
Figure 59.—Standing position, showing hasty sling adjustment.
easily and naturally at the target. The right hand grasps the small of the stock, thumb either around or along the stock; the left hand is near the lower band swivel, piece resting on the palm and in the crotch between thumb and fingers, left elbow as nearly directly under the rifle as possible. The neck and jaw are pressed firmly against the stock. The trigger is squeezed with the first or second joint of the right forefinger. Standing position—feet 12 to 24 inches apart. Kneeling position the left lowei leg is vertical, point of left elbow just over point of knee, the firer sitting on right heel or side of right foot. Sitting position feet 12 to 24 inches apart and dug into ground, upper arms braced against insides of knees. Prone position—legs straight and veil apait, insides of feet flat on ground (or nearly so), shoulders raised on elbows. (See figs. 59 to 62, incl.)
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Q. What is the purpose of the sling? A. It is used to carry the rifle on long marches, and to afford a steady position and thus improve aim in firing.
Figure 60.—-Kneeling position, showing loop sling adjustment.
Figure 61.—Sitting position.
Q. How is the sling used in firing? A. There are two adjustments called the hasty sling and the loop adjustment. (See figs. 59 and 60.)
Q- What is the most important thing in successful rifle shooting? A. Correct trigger squeeze.
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Q. Explain how to squeeze the trigger correctly? A. The trigger should never be jerked as this always spoils the aim. The rifleman alines his sights accurately on the bull’s-eye, and when he has them alined he slowly squeezes the trigger. If the sights wander off the bull’s-eye he stops squeezing the trigger, but holds what he has taken up. He brings his sights back into alinement and then continues to squeeze the trigger. The trigger is squeezed only when the sights are on the bull’s-eye. After two or possibly three squeezings the rifle goes off with the sights properly alined. 'This procedure is the secret of successful rifle shooting.
Q. What mechanisms is the soldier permitted to disassemble ? A. The bolt and magazine mechanisms only.
Describe how to disassemble and assemble the bolt mechanism. A.
Figure 62.—Prone position.
(1) To disassemble bolt mechanism.— (a) Place cut-off at the center notch.
(b) Cock piece and turn safety lock to a vertical position.
(c) Raise bolt handle and draw out bolt.
(d) Hold bolt in left hand, press sleeve lock in with thumb of right hand to unlock sleeve from bolt, and unscrew sleeve by turninn to the left.
(e) Hold sleeve between forefinger and thumb of the left hand, draw cocking piece back with middle finger and thumb of right hand’ turn safety lock down to the left with the forefinger of the right hand' and allow the cocking piece to move forward in sleeve, thus partially relieving the tension of mainspring.
(/) With the cocking piece against the breast, draw back firing pin sleeve with the forefinger and thumb of right hand, and hold it in this position while removing the striker with the left hand.
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(y) Remove firing pin sleeve and mainspring.
(A) Pull firing pin out of sleeve.
(?) Turn extractor to the right, forcing its tongue out of its groove in the front of the bolt, and force the extractor forward and off the bolt.
Figure 63.—Disassembling bolt mechanism.
(2) To assemble bolt mechanism.—(«) Grasp with the left hand the rear of the bolt, handle up, and then turn extractor collar with the thumb and forefinger of the right hand until its lug is on a line with the safety lug on the bolt.
(&) Take extractor in the right hand and insert lug on the collar in the undercuts in the extractor by pushing the extractor to the rear
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SLEEVE LOCK
SLEEVE
BOLT
FIRING PIN ROD
_ ---\
STRIKER
MAINSPRING .
y—SLEEVE LOCK FIRING PIN SLEEVE
Figure 64.—Firing pin.
L- l"' COCKING PIECE / SAFETY LOCK \ / 1
/ SLEEVE \ \ a
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until its tongue comes in contact with the rim on the face of the bolt (a slight pressure with the left thumb on the top of the rear part of the extractor assists in this operation).
(
□ 9 □ H U16 Q6 Ud
Figure 83.—Block and tackle combinations.
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Q. What mechanical advantage is gained by the use of blocks? A. In simple tackles the mechanical advantage gained is a direct function of the number of ropes supporting the load. Thus, if the movable block is a double one, then four ropes will sustain the load and the mechanical advantage gained is 4.
Q. Draw sketches showing: a whip tackle; a whip on a whip; a runner; a gun tackle; a luff tackle; and show the power of each. A. See figure 83.
Q. Why is a runner a more powerful tackle than a whip? A. Because the pull is in the same direction as that in which the load is moved instead of in the opposite direction.
Q. Rig a whip tackle; gun tackle; luff tackle.
Q. What is a chain or triplex block? A. A chain or triplex block consists of a train of gears operated by a large wheel over which an endless chain passes. Power is applied to this chain. The gears operate a sprocket wheel over which runs a heavy chain, the links of which fit into the sprockets. The heavy chain lifts the weight and is provided with a hook for supporting the weight. Chain blocks are rated according to their lifting capacities and range by half-ton changes from one to five tons.
59. Slings.—Q. What are slings made of? A. Slings are made of manila rope, wire rope, or chains. The most common is a manila sling made by splicing the two ends together.
Q. How is a sling used? A. To use a sling, pass it around the article to be lifted. Pass the bight formed by one end through the bight formed by the other and then over the lifting hook. If the sling is the same size as the lifting rope, it should make a minimum angle of 30° with the horizontal. At this angle the stress in each branch of the sling is equal to the stress in the lifting rope. If the angle is greater than 30° the load is limited by the strength of the lifting rope; if less than 30° by the strength of the sling.
Q. How do you make a barrel sling? A. To sling a barrel horizontally, make a bowline with a long bight. To sling a barrel vertically, make an overhand knot on top of the two parts of the rope; open out the knot and slip each half of it down the sides of the barrel; secure with a bowline.
60. Lashings.—Q. How should two spars be lashed at right angles? A. Make a clove hitch around the upright a few inches below the transom. Bring the lashing under the transom, up in front of it, horizontally behind the upright down in front of the transom, and back behind the upright at the level of the bottom of the transom and above the clove hitch. Keep the following turns outside the
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previous ones on one spar and inside on the other, not riding over the turns already made. Make four more turns. Make two trapping turns between the spars, around the lashing, and finish the lashing off either around one of the spars or any part of the lashing through which the rope can be passed. Do not make the final clove hitch around the spar on the side toward which the stress is to come, as it may jam and be difficult to remove. While tightening, beat the lashing with a handspike or pick handle. This is called a square lashing.
Q. How should two spars be lashed for a pair of shears? A. Lay the two spars alongside each other with the points below which the lashing is to be made resting on a skid. Make a clove hitch around one spar, and take the lashing loosely eight or nine turns about the two spars, above the clove hitches, without riding. Make two or more frapping turns between the spars, and finish the lashings off with a clove hitch above the turns on one of the spars. Open the butts of the spars and pass a sling over the fork. Hook or lash a block to this sling. Make fast fore and back guys with clove hitches to each spar just above the fork.
Q. How should three spars be lashed for a gin or tripod? A. Mark on each spar the location of the center of the lashing. Lay two of the spars parallel to each other with an interval a little greater than the diameter of a spar. Rest their tips on a skid and lay the third spar between them with its butt in the opposite direction so that the marks on the three spars will be in line. Make a clove hitch on one of the outer spars below the lashing and take eight or nine loose turns around the three. Take a couple of frapping turns between each pair of spars in succession and finish with a clove hitch on the central spar above the lashing. Pass a sling over the lashing and the tripod is ready for raising.
61. Gins and shears.—Q. Describe a gin. A. A gin is a tripod of poles or spars. The two outside poles are called legs and the third called the pry pole. A gin requires no guys.
Q. What is a gin used for? A. For lifting heavy weights vertically.
Q. Name the different parts of a garrison gin. A. Two legs, pry pole, bolt and clevis, windlass and ratchet, two handspikes, three shoes, two braces, and tackle.
Q. How much can be lifted safely with it? A. About 17,000 pounds.
Q. Explain briefly how a garrison gin is assembled and raised. A. The legs and pry pole are laid on the ground with the heads together and in position for assembling. The head is then assembled by putting the pin through the legs, pry pole, and clevis. The windlass is
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put in place and the braces are brought up and put in their places. The gin is raised, after assembly, by raising the head and bringing up the foot of the pry pole toward the feet of the two legs. (See fig. 81.)
Q. Describe the shears. A. Shears consist of two spars, of a size suitable for the weight to be raised, lashed together at the fork. A tackle is fastened to the lashing by a strap or otherwise, the hook is moused, and holdfasts are required.
Q. What are shears used for? A. Shears are used for lifting heavy weights to move them a short distance, as in loading or unloading a ship or railroad car.
Q. How are shears held in position after being raised? A. By means of guys. (Lines from the top of the shears to holdfasts on the ground.)
Q. How are the shears raised? A. If not too heavy, lift the head and haul in on the proper guys. If too heavy to raise in this way, form a crutch by lashing together two poles near their upper ends, the feet of the crutch being slightly in rear of the heels of the shears and secured to prevent them from slipping. Lay the rear guy over the crutch and raise the crutch by means of two light guy ropes, until it is inclined at an angle of about 45° to the front. Haul on the rear shear guy, allowing the crutch to rise as the shears rise. After the shears are raised high enough so that the crutch ceases to act, it is lowered by means of its guy ropes. Footings should be prepared for heavy shears on hard ground, and the legs should be connected by a lashing to prevent spreading.
Q. How is a load moved horizontally by means of shears? A. By slacking off on one guy and taking up on the other. Tackle may be used for this purpose if necessary.
62. Anchorages.—Q. What is the purpose of an anchorage? A. It furnishes a holdfast for the tackles or guy cables in handling heavy loads by means of tackles, gins, shears, etc.
Q. Describe two forms of anchorages. A. The picket holdfast is a succession of pickets driven into the ground in continuation of the guy or cable and at right angles in a vertical plane to the line of pull, connected from the top of one picket to the bottom of the next, with the direct pull on the bottom of the first picket. A deadman is a log, rail, or other arrangement buried in the ground, horizontally at right angles to the line of pull, which is applied to the center of the deadman.
Q, What is the purpose of a holdfast? A. Holdfasts are used to anchor a line to the ground, as for a guy.
Q. How is a holdfast made? A. Drive stout pickets into the ground, one behind the other, in the line of pull. Secure the head of each
422589°—42---12
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picket, except the last, by a lashing to the one behind it. Tighten the lashings by rack sticks, and then drive the points of these into the ground to hold them in position. The distance between pickets should be several times the height of the picket above the ground. A single good ash picket, 3 inches in diameter, driven 5 feet into good solid earth, will stand a pull of about 700 pounds.
Q. What is the purpose of a deadman? A. A deadman has the same use as a holdfast except that it has greater strength, but requiring more labor to construct.
Q. How is a deadman prepared? A. Lay a log or timber in a transverse trench with an inclined trench intersecting it at its midpoint. Pass the cable down the inclined trench, take several turns around the log, and fasten the cable to the log by half hitches and marline stopping. If the cable is to lead horizontally or incline downward, pass it over a log at the outlet to the inclined trench. If the cable is to lead upward, the log is not necessary, but the deadman must be buried deeper. The strength of the deadman depends upon the strength of the log and holding power of the earth.
Q. How can you determine the holding power of a deadman? A. For given cable pull, the number of square feet of deadman bearing surface required is determined by dividing the total pull to be placed on the deadman by the value given for the depth and cable inclination selected in table LXVI, FM 5-10.
63. Jacks.—Q. Name two types of jacks. A. Screw jacks and hydraulic jacks..
Q. What is the usual maximum lift of a screw jack? A. Usually from 16 to 18 inches. Care should be taken that it is not screwed too high.
Q. What liquid is used for filling hydraulic jacks? A. A mixture of alcohol and water.
Q. How would you determine what mixture of fluid to put into a hydraulic jack? A. Consult the manufacturer’s handbook or operational instructions.
Q. Can all hydraulic jacks be used in both the horizontal and vertical positions? A. No. They are manufactured in two classes, horizontal jacks and base jacks. Horizontal jacks may be used in any position. Base jacks are used in the upright position, but may be inclined provided that the head is always kept higher than the base.
Q. How may the two classes of jacks be distinguished? A. They may be distinguished by the fact that the base jack has the pump and reservoir within the ram while the horizontal jack, which is
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the shorter one, has a separate piece for the cylinder which has no connection with the reservoir except through the pump and the lowering passage.
Q. How is the hydraulic jack filled? A. To fill the hydraulic jack start with the ram down. Remove the lowering valve and hexagonal cap. Fill through the large hole. Small amounts necessary to replace liquid which has leaked out may be put in by removing the small screw and filling.
Figure 84.—Base jack.
Figure 85.—Screw jack.
Q. How is the hydraulic jack emptied? A. To empty, have the ram down, place the finger over the escape hole in the cylinder, pump the ram until the bottom of it is above the hole, then open the lowering valve and remove the finger from the escape hole, allowing air to enter under the ram. The ram may now be lifted out. Remove the lowering valve and hexagonal cap and invert the jack to allow the liquid to run out.
179
g-Socket 'Arm • Hnuck/e
'//'head
■Pam Piston
~Cy/inder
.-'Pump s'"Psion Ur tee.
s'Back F/otv Passages /Packing .-'Pump Ya/ve.
• ■'Pump P/ug
; I* Pam hacking
5 Packing Pmgs
; X-Va/ue Spring
’ I"Pamp Bonnet
Aston Packing Aston P Pi ng Aston Bonnet.
Pm -
Bottom hacking Bottom PPmg Tiffin
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Q. What general precautions should be taken in using the hydraulic jack? A. The ram should be kept down when not in actual use. In raising a weight the lever should be inserted in the socket with
the projection down. The lowering valve should be closed. The lever should be worked up and down with a slow steady stroke. A weight is lowered by opening the lowering valve. The speed of low-
180
C Lowering valve - Knuckle Pump nut
Pump Pump valve Pump valve spring
Figure 86.—Horizontal hydraulic jack.
/pom packing •— RP Ring ' R.P Pinenut — Bottom packing '"'BP Ring "■-Pump small nut
Ram head
Ram " Cylinder
Cap “ Socket-rQ
Knuckle ’g
Reservoir-— Piston --
Pump——.
Piston valve— Piston packing Rston packing ring"" Piston valve bonnet"^
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ering is controlled by the valve. It should be lowered slowly and never checked suddenly. The jack is designed to lift its rated load with one man operating the lever.
Q. What general precautions should be taken in using the screw jack? A. It must never be screwed out to the full extent in raising a weight. The threads must be kept clean, lubricated, and free from burs. The jack should not be used to lift weights greater than its rated capacity.
64. Blocks and wayplanks.—Q. What are the requirements of blocks? A. Blocks should be sound, free from knots, unpainted, and free from grease. Edges should not be splintered or rounded.
Q. What precautions should be used in erecting a crib ? A.
(1) The foundation should be level.
(2) Large enough blocks should be selected.
(3) The blocks should then be laid crossing each other in alternate tiers, and the weights supported should be made to bear equally upon all sides of the base.
Q. What is a wayplank and how is it used? A. A wayplank is a hard plank, preferably of oak, usually about 15 feet long, 12 inches wide, and 3 inches thick. Each end is beveled for a distance of 6 inches, the bevel on one end being on the side opposite the bevel on the other end. These planks are used chiefly for forming temporary tramways for rollers, or for the wheels of carriages bearing heavy weights, especially in crossing weak bridges.
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Chapter 10
INDICATION, IDENTIFICATION, AND CHARACTERISTIC FEATURES OF CLASSES OF AIRCRAFT
Paragraph
Classes and types of aircraft___________________________________________________ 65
Missions of aircraft__________________________________________________-_________ 66
Naval aircraft__________________________________________________________________ 67
Identification and indication of aircraft____________________________________ 68
65. Classes and types of aircraft.—Q. What are the two general classes of aircraft? A. Heavier-than-air and lighter-than-air.
Q. Name the general types of lighter-than-air aircraft. A. Observation balloons and dirigible airships.
Q. What are the general types of airships? A. Nonrigid, semirigid, and rigid.
Q. What are the heavier-than-air aircraft generally called ? A. Airplanes (aeroplanes), seaplanes, flying boats, or amphibians.
Q. What are the general types of combat airplanes used by the United States Army? A. Pursuit; bombardment; reconnaissance, observation, and liaison; and transport.
Q. How are pursuit airplanes classified? A. Interceptor, singleplace fighter, and multiplace fighter.
Q. How are bombardment airplanes classified? A. Heavy, medium, and light.
66. Missions of aircraft.—Q. What is the normal mission of pursuit airplanes? A. The interception, attack, and destruction of enemy aircraft in the air. The interceptor is usually a single seater with one or two powerful engines. The single-place fighter is used for escort and patrol in addition to normal pursuit missions. The multiplace fighter is used for escort and patrol duty near important objectives and against ground-troop formations.
Q. What are the normal missions of heavy and medium bombardment airplanes? A. To carry heavy bomb loads to great distances for attack of material objectives, and also to conduct long range strategic reconnaissance over land and sea.
Q. What are the normal missions of light bombardment airplanes? A. Light bombardment airplanes (formerly designated as attack) are designed to attack objectives of light construction, routes of communication, airdromes, troop movements, and concentrations of troops in the open or under light shelter. The light bombardment airplane
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GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 66-68 is the striking element of combat aviation which operates in direct support of ground forces. Identification of this type of airplane is especially important to ground troops.
Q. What are the normal missions of reconnaissance, observation, and liaison airplanes? A. They gather information of the enemy. The two later types operate in conjunction with our own forces performing fire-adjustment missions for artillery; maintaining contact with our front lines and marching columns; and carrying on other command, liaison, and courier missions.
Q. What are the missions of transport airplanes? A. Transport airplanes are not strictly a combat type of airplane. They are used for the transportation of personnel and supplies. Their importance is rapidly increasing when we consider the transportation of airlanding troops, parachute troops, and important supplies.
67. Naval aircraft.—Q. What types of airplanes are employed by our Navy, and to what types of Army airplanes do they correspond? A.
(1) Scouting-observation airplanes corresponding to observation airplanes.
(2) Fighter airplanes corresponding to pursuit airplanes.
(3) Torpedo-bombardment airplanes corresponding to bombardment airplanes.
(4) Patrol airplanes which do not correspond to any special type of Army airplane. The Navy has no type of airplane corresponding to the Army light bombardment airplane.
Q. Does the Navy make more extensive use of the biplane type of airplanes than the Army? A. Yes. They are used on carriers and on board other types of warships being launched from catapults. They are used for this purpose because they are more stable in flight at low air speeds than monoplanes.
Q. What are seaplanes and flying boats? A. They are airplanes equipped with floats (pontoons) or boat-shaped hulls instead of wheels, so that they may alight on water. Seaplanes have floats while flying boats have hulls.
Q. What is an amphibian airplane? A. It is an airplane having a boat-shaped hull, and also equipped with wheels (that can be retracted when operating on water) so that it can alight or take off from either a land or water surface.
68. Identification and indication of aircraft.—Q. Why is it important that ground personnel be familiar with the appearance in flight, method of operation, and characteristic sounds of airplanes?
A. These factors are the means by which airplanes are identified and indicated.
183
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COAST ARTILLERY CORPS
Q. What are the basic flight positions used for ready recognition of airplane types? A.
(1) Coming flight or front view.
(2) Passing flight or side view.
(3) Flight at lower altitude or top view.
(4) Overhead flight or bottom view.
(5) Maneuvering flight or perspective view.
Q. What is meant by coming flight or front view ? A. AU positions of flight in which only a general head-on view of the airplane may be had.
Q. What is meant by passing flight or side view? A. All positions of flight in which the side of the fuselage, vertical fin, and rudder are the major surfaces presented to view.
Q. What is meant by flight at lower altitude or top view? A. All positions of flight in which the upper sides of wings, fuselage, and horizontal tail surfaces are the major surfaces presented to view.
Q. What is meant by overhead flight or bottom view? A. All flight positions in which the under sides of wings, fuselage, and horizontal tail surfaces are presented to view.
Q. What is meant by maneuvering flight or perspective view? A. All flight positions which are different from straight and level flight. It includes banking, turning, climbing, diving, and combinations of such maneuvers. The airplane may present, momentarily at least, nearly all of the views presented under other conditions of flight.
<2- What characteristics of outline of'the airplane are most readily seen in overhead flight? A.
(1) Shape of wing.—The general shape and proportion of wings, as long and narrow, short and stubby.
(2) Type and shape of nose.—Nose extends much or little in advance of leading edge of wings; that is, plane is long-nosed or short-nosed.
(3) Length and shape of fuselage.—Compare the relatively short fuselage of the small and medium sized airplanes with the long, slender, streamlined appearance of the larger types.
(4) Location and number of engines.—In single engined airplanes the engine is located in the nose and by its type determines the shape of the nose; that is, with radial engines the nose is blunt and stubby, while with in-line and V-type engines the nose is more slender and pointed. In multi-engined airplanes the engines are usually housed in nacelles extending from the leading edge of the wings. In the unusual pusher types, the engines extend from the trailing edge of
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GUNNERS' INSTRUCTION, AA SEARCHLIGHT BATTERIES 68
the wings. Even at great altitudes when the number of engine nacelles cannot be exactly determined, their presence will give an unmistakable irregular outline to the wings warranting identification as multi-engined.
Q. What characteristics of outline are most readily seen in passing flight? A.
(1) Shape and outline of the fuselage.—It is short and chunky in smaller pursuit types; elongated and streamlined in larger types; long and thick bodied in larger bombardment types. Note outline being broken by such parts as cockpits, canopies over cockpits, and gun turrets.
(2) Shape of nose.—It may be slender and pointed, blunt and stubby, smoothly rounded, or shark-nosed.
(3) Note the relative size of the vertical fin and rudder compared to the fuselage.
Q. What characteristics of outline are most readily seen in coming or going flight? A.
(1) Relationship of wings to fuselage.—Has high-wing, midwing, low-wing, or parasol-wing types; dihedral angle, pronounced, moderate. or practically zero.
(2) Number of engines.—The irregularity of outline of wings will indicate a multi-engined type.
(3) Features of the vertical tail members.—It is usually possible to identify single- and double-rudder types.
(4) Undercarriages.—Nonretractable landing gear is usually plainly visible.
Q. What characteristics of outline are most readily seen in maneuvering flight? A. All the features previously pointed out may be momentarily visible.
Q. What characteristic methods of operation of pursuit assist in its identification? A. Pursuit normally operates in formation with the squadron of eighteen airplanes as the largest group operating as a unit. An observer noting one such formation should look below and to the front of it and above and to the rear of it for other units.
Q. What characteristic methods of operation of heavy and medium bombardment assist in its identification? A. They operate in column of three plane elements (route column) with successive elements stepped up or down from front to rear. They usually fly straight courses at medium or high altitude unless attacked from the air or by antiaircraft fire.
Q. What characteristic methods of operation assist in the identification of light bombardment ? A. They operate in formation at mini
185
TM 4-330
68
COAST ARTILLERY CORPS
mum or medium altitudes. They use the three plane element echeloned to the rear at approximately the same altitude. The normal operating unit is the squadron of nine airplanes with the largest formation the group of three squadrons. This type of aviation supports the operations of ground troops.
Q. What characteristics of operation of reconnaissance airplanes assist in their identification? A. They operate at any altitude from low to high; usually operate singly; fly straight courses unless attacked. Bombardment airplanes may perform long range reconnaissance.
RUDDER
(---^a'ling fl
\ ,<^Zy>-.ED6E (\jJ_NTRIMMING TABS
LEADINoXk^^5^^ L^^>>^^5ELEVATOR
EDG0f\\ A Bl LIZ E R
x WING\\ \R2r ' /^MARKING
5. \X FUSELAGE
T|. CABIN COCKPIT
Xr i
( ))] *ING >—AILERON
SPINNER]f-l---NOSeYaiR I
71 'NTAKE
' k WING SLOTS^\^"-W,
WINGTIP
Figure 87.—Nomenclature of airplane parts.
Q. What characteristic methods of operation assist in identification of observation and liaison airplanes? A. They operate almost entirely within own lines; fly singly on various courses at low and medium altitudes; will be seen circling over own troops and troop columns to drop messages and observe panels.
Q. What are some of the characteristic sounds of pursuit airplanes in flight? A. Pursuit airplanes in flight are characterized by sounds of fast rhythm, high pitch, moderate volume, and by extreme variations in pitch and tone while maneuvering.
Q. What are some of the characteristic sounds of heavy and medium bombardment airplanes while in flight? A. They have a fairly deep pitch, a moderately heavy volume, and a steady tone and rhythm.
Q. What are some of the characteristic sounds of light bombardment airplanes while in flight ? A. They have a heavy volume of sound due to low altitude; a fairly deep pitch, with tone and rhythm steady but varying considerably when maneuvering.
Q. State, in the order in which given, what information is given and the terms used in indicating aircraft during daylight. A.
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GUNNERS' INSTRUCTION, AA SEARCHLIGHT BATTERIES 68
(1) Designation of the reporting station by name or number.
(2) Number of airplanes, when they can be counted. If they cannot be counted the word “several” or the word “many” may be used.
(3) Type of airplane, such as “observation,” “pursuit,” etc., when they can be identified. In other cases the word “airplane” is used.
(4) Altitude, in general terms as follows: “very low” (below 500 yards) ; “low” (500 to 2,000 yards) ; “medium” (2,000 to 5,000 yards) ; or “high” (over 5,000 yards).
(5) Location, by the sector in which or toward which the aircraft are flying.
(6) Direction of flight, by one of the eight points of the compass: north, NE, east, SE, south, SW, west, NW.
Q. State which of these elements of information are given in indicating aircraft at night. A. Designation of reporting station, number of airplanes (“one,” “several,” or “many”), altitude, and location.
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68
COAST ARTILLERY CORPS
188
STRAIGHT
SWEPTBACK
ROUND TIP
ROUNDED TRAILING EDGf
'CUT
OUT
SWEPTBACK TA PERED
ELLIPTICAL ’
RAKED TIP
Figure 88.—Wing shapes.
TM 4-330
68
GUNNERS' INSTRUCTION, AA SEARCHLIGHT BATTERIES
^^^^ULLWING
\ TAPERED
I A R E TIP
) %R^T tapered 7
/ INNER OUTER /
/ SECTION SECTION^__^----J
' I r/1 INNER
/J fa\SEC T1 °
NEGATIVE DIHEDRAL
TAPERED
( T° J)
j ROOT AND TIP
Figure 88.—Wing shapes—-Continued.
189
TM 4-330
68
COAST ARTILLERY CORPS
(PARASOL MONOPLANE)
Figure 89.—Monoplanes.
190
HIGH-WING
MIDWING
LOW-WING
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES
TM 4-330
68
Figure 90.—Pursuit airplane.
191
BOTTOM VIEW
BOTTOMI VIEW
PERSPECTIVE VIEW
PERSPECTIVE VIEW
FRONT VIEW
FRONT VIEW
TOP VIEW y TOP VIEW
SCALE IN FEET SCALEtNFEET
~ - 5----io 15 '"50 5 o 5 io 15 20
TM 4-330
68
COAST ARTILLERY CORPS
192
BOTTOM -VIEW

PERSPECTIVE VIEW
PERSPECTIVE VIEW
FRONT VIEW
I
SIDE VIEW
FR.QNT VIEW
SIDE VIEW
TOP VIEW
SCALE IN FEET
TOP VIEW
SCALE IN FEET
Figure 91.—Pursuit airplane (interceptor).
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 68
SCALE IN FEET
5 • 5 10 <5 20 25 30 3S 40
Figure 92.—Multiplace fighter airplane.
422589°—42---13
193
BOTTOM VIEW
PERSPECTIVE VIEW
FRONT VIEW
SIDE VIEW
TOP VIEW
TM 4-330
68
COAST ARTILLERY CORPS
194
BOTTOM VIEW
BOTTOM VIEW
PERSPECTIVE VIEW
PERSPECTIVE VIEW
FRONT VIEW
SIDE VIEW
FRONT VIEW
SIDE VIEW
SCALE.* feet ... ALE .N FEET
5" 0 5 io IS io 25 }0 )5 40 45 50 55 60 5 0 5 '0 15 20 25 JO )5 40 4J JO
® ®
Figure 93.—Bombardment airplane.
TM 4-330
GUNNERS INSTRUCTION, AA SEARCHLIGHT BATTERIES 68
Figure 93.—Bombardment airplane—Continued.
195
BOTTOM VIEW
BOTTOM VIEW
PERSPECTIVE VIEW
PERSPECTIVE VIEW
F R.ONT VIEW
SIDE VIEW
FRONT VIEW
SIDE VIEW
TOP VIEW
SCALE IN FEET
J" o 5 io t5 ’io—*5 3° 35 40 V) 50
TOP VIEW
SCALE IN FEET "o "o l"o 35AOA^Q
TM 4-330
68
COAST ARTILLERY CORPS
Figure 94.—Light bombardment (attack) airplane.
BOTTOM VIEW
SCALE IN FEET
5 O ? 10 IJ 20 25 JO
Figure 95.—Observation airplane.
196
PERSPICT1VE VIEW
front view
PERSPECTIVE VIEW
BOTTOM VIEW
FRONT VIEW
SIDE VIEW
SIPE VIEW
TOP VIEW
TOP VIEW
TM 4-330
GUNNERS’ INSTRUCTION, AA SEARCHLIGHT BATTERIES 68
SCALE IN FEET » io n n 15 v
Figure 96.—Observation amphibian airplane.
Scale in regT 5 o 5 io 15 zo 15 30 )5 m
Figure 97.—Transport airplane.
197
BOTTOM VIEW
BOTTOM VIEW
PERSPECTIVE view
FRONT VIEW
FRONT VIEW
SIDE VIEW
SIDE VIEW
TOP VIEW
TOP VIEW
TM 4-330
INDEX
Aircraft: Paragraph Page
Classes and types___________________________________________ 65 182
Identification______________________________________________ 68 183
Indication________________________________________________ 68 183
Missions____________________________________________________ 66 182
Naval_______________________________________________________ 67 183
Ammunition:
Pistol, automatic, caliber .45______________________________ 53 152
Rifle, U. S., caliber .30:
Ml_____________________________________________________ 52 141
M1903__________________________________________________ 51 127
Anchorages______________________________________________________ 62 177
Assignment of topics___________________________________________ 2 2
Blocks and tackle____________________________________________- 58 171
Blocks, wood--------------------------------------------------- 64 181
Commands, drill_________________________________________________4-6 3
Connections, telephone__________________________________________ 42 91
Control mechanism, lamp:
M1940_______________________________________________________ 24 64
M1941_______________________________________________________ 23 63
Control stations:
General Electric:
Maintenance_____________________________-___________ 35 81
Nomenclature. _________________________________________ 12 37
Operation______________________________________________ 34 79
Purpose_____________________________________________________ 29 76
Sperry:
Maintenance____________________________________________ 33 79
Nomenclature____________________________________________ 9 18
Operation:
M VI_______________________________________________ 32 78
M1934_____________________________________________ 31 77
M1941, M1940, M1939, and M1937_____________________ 30 76
Convoy and march rules---------------------------------------- 47 119
Cordage----------------------------------------------------- 57 166
Corrections, sound location_____________________________________ 36 81
Definitions:
Antiaircraft artillery terms_____________________________ 49, 50 124, 126
Cordage and mechanical maneuver terms-------------------- 54, 58 161, 171
Discipline, motor transportation-------------------------------- 47 119
Drill:
Commands-------------------------------------------------- 4—6 3
Organization_________________________________________________ 3 3
Table________________________________________________________ 7 8
199
Paragraph Page
Engine, power plant, maintenance____________________________________ 20 59
General Electric equipment:
Control stations:
Maintenance________________________________________________ 35 gl
Nomenclature_______________________________________________ 12 37
Operation__________________________________________________ 34 79
Power plants. (See Power plants.)
Searchlights:
Maintenance_________________________________________________ 28 74
Nomenclature________________________________________________ 11 29
Operation___________________________________________________ 27 79
Generator, power plant, maintenance__________________________________ 19 58
Gins and shears____ ..._________________________________ 61 176
Identification, aircraft-.__________________________________________ 68 183
Indication, aircraft_________________________________________________ 68 183
Jacks, screw and hydraulic_________________________________________ 63 178
Knots 55 162
Lamp and lamp control mechanism, operation:
Ml940----------------------- __ _ __ _____________________ 24 64
Ml941--------------------------- _ _ --------------------------- 23 63
Lashings------------------- ---------------------------------------- 60 175
Locators, sound. (See Sound locators.)
Lubrication schedule, power plants_______________________________ 21 60
Messages, telephone__________________________________________________ 41 gg
Maintenance:
Control stations:
General Electric____________________________________________ 35 gi
Sperry------------------------------------------------------ 33 79
Motor vehicles___________________________________________________ 45 113
Pistol, automatic, caliber .45__:_______________________________ 53 152
Power plants:
Engine. ---------------------------------------------------- 20 59
Generator__________________________________________________ 19 5g
Lubrication_________________________________________________ 21 60
Rifle, U. S., caliber .30:
Ml-- ------------------------------------------------------- 52 141
Ml903 (Springfield)_________________________________________ 51 127
Searchlights:
General Electric-- _________________________________________ 28 74
Sperry. _- _-------------------------------------------- 26 69
Sound locators:
Ml series__________________________________________________ 3g 83
M2 series___________________________________________________ 40 87
Telephone______•_________________________________________________ 42 91
Motor transportation:
Discipline--------- - - ---------------------------------- 47 119
Rules, convoy and march_________________________________________ 47 119
Trucks, handling under adverse conditions_______________________ 48 121
200
TM 4-330
INDEX
Motor vehicles: Paragraph Page
Maintenance------------------------------------------------------ 45 113
Nomenclature---------------------------------------------------- 43 106
Operation________________________________________________________ 44 109
Trouble shooting and minor repairs------------------------------- 46 117
Naval aircraft________________________________________________________ 67 183
Nomenclature:
Control stations:
General Electric_____________________________________________ 12 37
Sperry ------------------------------------------------------- 9 18
Motor vehicles___________________________________________________ 43 106
Pistol, automatic, caliber .45----------------------------------- 53 152
Power plants:
General Electric_____________________________________________ 13 41
Sperry_______________________________________________________ 10 25
Rifle, U. S„ caliber .30: Ml________________________________________________________________ 52 141
Ml903 (Springfield)----------------------------------------- 51 127
Searchlights:
Genera] Electric--------------------------------------------- H 29
Sperry________________________________________________________ 8 9
Sound locators:
Ml series---------------------------------------------------- 15 43
M2 series_____________________________________________________ 16 43
Operation:
Control stations:
General Electric____________________________________________ 34 79
Sperry:
M VI____________________________________________________ 32 78
M1934__________________________________________________ 31 77
M1941, M1940, M1939, and M1937__________________________ 30 76
Lamps and lamp control mechanism:
M1940________________________________________________________ 24 64
M1941________________________________________________________ 23 63
Motor vehicles__________________________________________________ 44 109
Power plants_____________________________________________________ 18 54
Searchlights:
General Electric_____________________________________________ 27 70
Sperry_______________________________________________________ 25 67
Sound locators:
Ml series____________________________________________________ 37 81
M2 series____________________________________________________ 39 84
Organization, searchlight section-------------------------------------- 3 3
Pistol, automatic, caliber .45---------------------------------------- 53 152
Power plants:
Description_____________________________________________________ 17 49
Engine, care____________________________________________________ 20 59
Generator, care_________________________________________________ 19 58
Lubrication schedule-------------------------------------------- 21 60
201
TM 4-330
INDEX
Power plants—Continued.
Nomenclature: Paragraph Page
General Electric_______________________________________ 13 41
Sperry----------- ----------------■-------------------- 10 25
Repairs, minor, motor vehicles__________________________________ 46 117
Rifle, U. S., caliber .30:
Ml---------------------------------------------------------- 52 141
Ml903 (Springfield)__________________________________________ 51 127
Searchlight section organization__________________________________ 3 3
Searchlights:
Definitions------------------------------------------------- 49, 50 124, 126
Description_________________________________________________ 22 61
General Electric. {See General Electric equipment.)
Sperry. {See Sperry equipment.)
Shears and gins_________________________________________________ 61 176
Slings---------------------------------------------------------- 59 175
Sound locators:
Corrections, reason for________________.____________________ 36 81
Description____ ________________________________________ 14 42
Ml series:
Maintenance______ _________1___________________________ 38 83
Nomenclature____________________________________________ 15 43
Operation_______________________________________________ 37 si
M2 series:
Maintenance_____________________________________________ 40 87
Nomenclature___________________________________________ 16 43
Operation-------- -------------------------------------- 39 34
Sperry equipment:
Control stations:
Maintenance____________________________________________ 33 79
Nomenclature________________________________;__________ 9 18
Operation:
M VI------------------------------------------------ 32 78
M1934_______________________________________________ 31 77
M1941, M1940, M1939, and M1937______________________ 30 76
Lamp and lamp control mechanism:
M1940___________________________________________________ 24 64
M1941------------------2------------------------------- 23 63
Power plant, nomenclature____________________________________ 10 25
Searchlights:
Maintenance____________________________________________ 26 69
Nomenclature_____________________________________________ 8 9
Operation_______________________________________________ 25 67
Splices, rope-------------------------------------T_____________ 56 164
Springfield rifle________________________________________________ 51 127
Tackle and blocks________________________________________________ 58 171
Telephones:
Laying wire__________________________________________________ 42 91
Making connections___________________________________________ 42 91
Messages, sending, receiving, and recording__________________ 41 88
202
TM 4-330
INDEX
Telephones—Continued. Paragraph Page
Tests_______________________________________________________ 42 91
Topic assignment__________________________________________________ 2 2
Trucks, handling under adverse conditions------------------------ 48 121
Wayplanks________________________________________________________ 64 181
Wire, telephone, laying------------------------------------------ 42 91
[A. G. 062.11 (6-13-41).]
By order of the Secretary of War :
G. C. MARSHALL,
Chief of Staff. Official :
E. S. ADAMS,
Major General,
The Adjutant General.
Distribution :
I Bn and H4 (3) ; IC4.
(For explanation of symbols see EM 21 6.)
203
U. S. GOVERNMENT PRINTING OFFICE: 1942
For sale by the Superintendent of Documents, Washington, D. C.
DRILL TABLE
Drill of the searchlight section (ch. S')
Details prepare for action EXAMINE EQUIPMENT REST STAND BY TRACK 1 CHANGE TARGET IN ACTION OUT OF ACTION MARCH ORDER
Chief of section (also sound locator chief and in charge of truck No. 1). Searchlight commander (also control station chief and in charge of truck No. 2). Commands: PREPARE FOR ACTION. Indicates location for sound locator, control station, searchlight, and power plant, and parking place for the two trucks. Conducts truck No. 1 to searchlight position, supervises unloading and setting up searchlight; to control station position, and supervises unloading and setting up control station; and to sound locator position, and supervises unloading and setting up sound locator. Repeats command. Supervises unloading of power plant at power plant position. Supervises laying and connection of power (yellow) cables from power plant position to searchlight position. Supervises laying and connecting of search-light-sound locator (blue) cable, and searchlight-control station (red) cable. Proceeds to control station. Commands: EXAMINE EQUIPMENT. Supervises examination of equipment, especially that of sound locator squad. Directs orienting and synchronizing of equipment. When equipment is found correct and orientation completed, he directs telephone operator (No. 4) to report, “No. in order.” Note.—Parallax corrections are determined and set on the acoustic corrector at this time. Assures himself the buzzers operate. Supervises examination of searchlight, control station, and power plant equipment. Assists in orienting and synchronizing searchlight and control station from searchlight. Has power put on and tests functioning of distant electrical control and zero-reader system. Assures himself the buzzers operate. When correct he reports “Searchlight and control station in order” to the chief of section. After reporting “In order,” if no warning of a target has been received, he commands: REST. Details one listener and a telephone operator to remain on the alert. Arranges for relief of men on duty at hourly or half-hourly intervals. Shares watches with searchlight commander. Repeats command. Shares watches with chief of section. Gives or repeats: STAND BY. Sees that all members of squad are alerted and at their posts. Supervises preparations to go into action. When reports from advanced listening post or platoon command post come in, directs locator in proper direction and directs locator crew to search. Estimates speed (or receives from command post the estimated speed) of target and gives it to acoustic corrector operators. Reports “No. — on target,” when target has been definitely located by listeners. Repeats command of chief of section. When power is on all lines, and searchlight, control station, and power plant are ready for action, he reports “light standing by” to chief of section. When “No. — on target” has been reported, he causes elevation and azimuth controllers to direct searchlight by means of distant electric control, so that pointers of zero reader system are continuously centered. Gives command: TRACK, to sound locator squad when they report “On target.” When he estimates that the most favorable time for going into action has arrived, he reports to the command post, “No. ready.” Repeats command and causes azimuth and elevation controllers to center zero readers continuously. Repeats or gives command. Causes sound locator crew to point locator in direction of new target. If new target is not already illuminated, causes personnel to search for and pick up target in usual manner. Repeats command. Causes crew of control station to center zero reader pointers, thereby pointing light in direction of new target. If target is not already illuminated, he searches for it and picks it up in the customary manner. Repeats or gives command by voice or signal. Continues to supervise locator crew as they track target. Looks for target and reports illumination or flicks to searchlight commander. Repeats command of chief of section and signals No. 7. Causes Nos. 5 and 6 to commence an immediate search for target, using their respective handwheels. Observes light beam through binoculars. Calls “Data” when he wishes Nos. 5 and 6 to center zero readers exactly. When the target is flicked, he commands: FLICK, and takes over operation of control station, following target until out of range or until directed otherwise. He carries target in side of light beam closest to gun battery firing. If command IN ACTION is received before sound locator is on •target, he searches near intersection of other beams until target is illuminated or locator is on target. Nos. 1 and 2 continue to track target. Continues to operate acoustic corrector by keeping pantograph pointer in center of cross on mirror. Repeats all messages. Looks for target, and reports illumination or flicks to chief of section. Nos. 5 and 6 search by slowly moving their zero reader pointers first to one side and then to the other of zero position. When searchlight commander calls “Data,” they center the zero readers exactly. When airplane is illuminated, they withdraw so as to avoid interference with control of beam. Closes main arc switch on signal, thereby lighting searchlight. Keeps watch on instruments to see that arc operates at 78 volts and 150 amperes. Recarbons arc at first break in operations after positive carbon is half burned (after about 45 minutes of operation). Repeats or gives command by voice or signal. Causes locator crew to continue tracking target until a new target is assigned or REST is given. Repeats command of chief of section and signals No. 7. Causes control station crew to continue tracking target until directed otherwise. Repeats or gives command: MARCH ORDER. Supervises knocking down and loading of sound locator at locator position; of control station at control station position; and of searchlight at light position. Checks to see that all hold-down devices in truck No. 1 are properly fastened. When all equipment has been secured in traveling position, he gives instructions as to next move to searchlight commander (who is in command of truck No. 2) and causes crews to get on trucks. Repeats command. Is picked up by truck No. 2 and taken to sound locator position. Supervises picking up of sound locatorsearchlight (blue) cable and control station-searchlight (red) cable by truck No. 2. Supervises picking up of searchlight-power plant (yellow) cables by truck No. 2. Supervises loading of power plant in truck No. 2. Checks to see that hold-down devices are fastened. Causes men assigned to ride in truck No. 2 to take places on command from chief of section. Confers with chief of section as to next move of unit.
Azimuth listener. Elevation listener. Nos. 1 and 2. Ride in truck No. 1. Acoustic corrector operator. No. 3; rides in truck No. 2. Telephone operator. No. 4; rides in truck No. 2. Azimuth controller. Elevation controller. Nos. 5 and 6. Ride in truck Nos. 1 and 2, respectively. Searchlight operator. No. 7; rides in truck No. 1. Assist in unloading and setting up searchlight, control station, and sound locator from truck No. 1. No. 1 connects blue cable to locator. No. 2 removes pantograph from box and places it on sound locator and drives stakes to show direction to OP’s and other four searchlights of the platoon. Assists in unloading power plant from truck No. 2. Assisted by No. 6, moves power cable (yellow) reel to rear end of truck. Pays out cables as truck goes from power plant to searchlight. Assisted by No. 6, moves lightlocator (blue) and light-control station (red) cable reels to rear end of truck. Pays out blue cable as truck goes from light to control station and locator. Leaves truck No. 2 on arrival at position and goes immediately to telephone wire connection. Connects telephone and places it near sound locator. Calls platoon command post to see that telephone line is functioning. Reports condition of telephone line to chief of section as soon as he arrives at locator position. No. 5 assists in unloading and setting up searchlight. Assisted by Nos. 1 and 2 unloads and sets up control station. Removes automatic rifle from truck and places it in convenient position near control station. Remains at control station. Connects red cable when delivered. No. 6 assists in unloading and placing power plant. Assists No. 3 in moving yellow cable reel to rear of truck, and in paying off yellow cables as truck moves from power plant to light. Assists No. 3 in moving blue and red cable reels to rear of truck. Pays out red cable as truck moves from light to control station. Remains at control station. Unloads searchlight from truck No. 1, assisted by Nos. 1, 2, 5, and 9. Sets up and levels searchlight, assisted by Nos. 1, 2, 5, and 9. Connects yellow, blue, and red cables. Removes extended hand control from truck. Prepares searchlight for action. Procures cleaning and greasing materials. Verify level of locator, functioning of elevating and traversing mechanisms, and assist in orienting locator. Test helmets for comfort and fit, and make sure that they are connected properly (not reversed). No. 2 checks cut-out switch which reduces noise from the data transmitters. No. 3 checks functioning of acoustic corrector; assists in orienting by zeroing parallax and target speed scales and sighting on datum point. After orienting and synchronizing have been completed, sets in parallax correction. Tests functioning of telephone with platoon command post. Nos. 5 and 6 together examine control station and test distant electric control by elevating and traversing searchlight. Both assist the searchlight commander to orient and synchronize the control station and searchlight. After entire unit has been oriented and synchronized they verify that movement of azimuth and elevation handwheels produce movement of the zero reader needles in proper direction. Examines searchlight and verifies electrical connections. Sees that fresh carbons (positive with preformed crater) are in place in light mechanism. Verifies that spare carbons are on hand. Assists in orienting and synchronizing. If allowable, tests light mechanism by turning on arc. Note.—In many situations it is unwise to test light mechanism by turning on arc at light position. This difficulty may be overcome by covering front of light with tarpaulin, piece of canvas, etc. Verifies that extended hand control is close to light and ready for Take turns on duty as listener. Man on duty remains alert, either on locator or in immediate vicinity. On detecting presence of aircraft he notifies chief of section. Takes turns on duty as listener. Man on duty remains alert, either on locator or in immediate vicinity. On detecting presence of aircraft, he notifies chief of section. Remains at phone until relieved. Watches for appearance of other searchlights. Repeats messages to chief of section. Informs chief of section of appearance of adjacent searchlights in action. No. 5 takes automatic rifle to telephone operator’s post. (There it will be fired by whoever is on duty at time of attack.) Both Nos. 5 and 6 take turns in relieving telephone operator as directed by chief of section. Turns off arc, if on. Relieves No. 8 at power plant as directed by chief of section. Fires automatic rifle if attack occurs while on duty during rest period. Take posts and put on helmets. Move locator horns as directed by chief of section. When definitely on target, No. 1 reports “On target” to chief of section. No. 2 pushes push button to decrease a-c hum. Takes post at acoustic corrector and sets in estimated speed of target as received from chief of section. Repeats command and stands by for further telephone messages. Nos. 5 and 6 stand at their posts awaiting orders. Stands by at post alongside searchlight. Notes that voltmeter reads proper voltage. Track target, centering sound by means of handwheels. No. 1 gives chief of section, in low voice, such details as to numbers and types of planes and direction of flight, as he may determine from time to time. No. 2 releases button on locator so that data transmitters will operate at full voltage. Operates acoustic corrector so as to keep pantograph pointer centered in cross on mirror. Stands by for further messages. Nos. 5 and 6 continuously center zero readers by turning azimuth and elevation handwheels in proper direction. Stands by at post alongside searchlight, ready to strike arc. Cease tracking old target and point locator in direction of new target, as directed by chief of section. Listen for, pick up, and track target (by sound) in usual manner. Operates acoustic corrector in usual manner as soon as new target is picked up by listeners. Repeats command and stands by for further messages. Nes. 5 and 6, at direction of searchlight commander, center zero reader pointers, thereby pointing light in direction of new target. Operate in usual manner during search, pick-up and carry. Stands by for further orders. Nos. 1 and 2 continue to track target. Continues to operate acoustic corrector. Stands by for further messages. Nos. 5 and 6 continuously center zero readers by turning azimuth and elevation handwheels. Opens main arc switch, thereby extinguishing the light on signal. Stands by ready to close main switch on command. Assisted by Nos. 4 and 9, knock down and load sound locator. No. 1 verifies that locator parts are properly fastened by holddown devices. Assisted by Nos. 4 and 5, knock down and load control station. Assisted by Nos. 4, 5, 7, and 9, knock down and load searchlight. Places blue cable reel at rear end of truck No. 2. Reels in blue cable as fed in by other men on ground. Replaces full blue reel in front of truck body. Places power cable reel at rear end of truck body, and reels in yellow cables as fed in by other men on ground. Replaces full yellow reel in front end of truck body. Assists in loading power plant in truck No. 2. Disconnects telephone and places it on truck No. 1. Assists Nos. 1 and 2 in knocking down and loading locator, control station, and light. Leaves truck No. 1 at light and goes (with telephone) to truck No. 2 at power plant. Assists in loading power plant. Assisted by Nos. 1, 2, and 4, No. 5 knocks down and loads control station. Verifies that control station is properly fastened by hold-down devices. Assists in knocking down and loading searchlight. During travel on road, mans automatic rifle in forward end of truck No. 1. No. 6 is picked up by truck No. 2 and taken to locator position. Assists searchlight commander in feeding blue cable to No. 3 on truck No. 2. Gets on truck at control station, places red cable reel on rear end of truck, and reels in red cable. Assists No. 3 in placing full blue and red reels in proper position at front of truck, and in reeling in yellow cable. Disconnects cables at searchlight and secures light in traveling position. Assisted by Nos. 1, 2, 4, 5, and 9, loads searchlight on truck No. 1. Verifies that light has been properly fastened by hold-down devices.
Power plant operator and chauffeur, No. 2 truck. No. 8. Chauffeur, No. 1 truck. No. 9. Basic, assistant to No. 8. No. 10; rides in truck No. 2. Drives truck to power plant position. Assisted by Nos. 3, 6, and 10, unloads and places power plant in position. Removes automatic rifle from truck and places in convenient location near power plant. Drives truck successively to searchlight, control station, and locator positions, laying cables en route. Drives truck to positions indicated for searchlight, control station, and locator. Assists in unloading light and sound locator. Assists in unloading power plant. Holds ends of power (yellow) cables while they are being laid to light. Connects power cables to power plant. action. Drives truck to indicated parking position. Sees that truck is properly hidden from air or ground observation. Proceeds to power plant, where he sees that gasoline, oil, and water supply is correct. Starts motor and builds up volt» age to required voltage. Note.—See Operator’s Manual for correct procedure. If permis-sable, the searchlight is lighted to make the necessary adjustments. Drives truck to indicated parking position. Checks on truck to see it has ample gas, oil, and water and is in proper operating condition. Sees that truck is adequately hidden from air or ground observation. Checks on truck to see it has ample gas, oil, and water, and is in proper operating condition. Opens switches and shuts off motor. Takes turn with No. 7 on duty during rest period. Mans automatic rifle if attack occurs at the time. Performs duties as directed by chief of section. Performs duties as directed by chief of section. Starts motor, builds up voltage to proper no-load value; closes switches, and reports “Power plant ready” to searchlight commander. Performs duties as directed by chief of section. Performs duties as directed by chief of section. Continues as at STAND BY. Performs duties as directed by chief of section. Perforins duties as directed by chief of section. Stands by for further orders. Performs duties as directed by chief of section. Performs duties as directed by chief of section. Continues as at STAND BY, checking that voltage is at proper full load value and amperage is correct. Performs duties as directed by chief of section. Performs duties as directed by chief of section. Continues as at STAND BY, checking that voltage is at proper listening load value. Performs duties as directed by chief of section. Performs duties as directed by chief of section. Drives truck No. 2 to control station (where searchlight commander and No. 6 are picked up) thence to locator. Drives to searchlight (picking up blue and red cables en route). Assisted by Nos. 3, 4, 6, and 10, loads power plant on truck No. 2. Verifies that power plant is properly fastened by hold-down devices. Drives truck No. 1 successively to locator, control station, and searchlight. Assists in loading locator and light. Disconnects yellow power cables. Prepares power plant for movement. Assists in loading power plant. During travel on road, mans automatic rifle at tail gate of No. 2 truck.
422589°—42
NTSU LIBRARY
UNnliiinmR,ES' DENT0N-Tx 76203

(Form 14 - 5/73)
1000961124