[Title 49 CFR 213.329]
[Code of Federal Regulations (annual edition) - October 1, 2006 Edition]
[Title 49 - TRANSPORTATION]
[Subtitle B - Other Regulations Relating to Transportation (Continued)]
[Chapter II - FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF]
[Part 213 - TRACK SAFETY STANDARDS]
[Subpart G - Train Operations at Track Classes 6 and Higher]
[Sec. 213.329 - Curves, elevation and speed limitations.]
[From the U.S. Government Publishing Office]


49TRANSPORTATION42006-10-012006-10-01false213.329Sec. 213.329TRANSPORTATIONOther Regulations Relating to Transportation (Continued)FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OFTRACK SAFETY STANDARDSTrain Operations at Track Classes 6 and Higher
Sec. 213.329  Curves, elevation and speed limitations.

    (a) The maximum crosslevel on the outside rail of a curve may not be 
more than 7 inches. The outside rail of a curve may not be more than \1/
2\ inch lower than the inside rail.
    (b) (1) The maximum allowable operating speed for each curve is 
determined by the following formula:
[GRAPHIC] [TIFF OMITTED] TR22JN98.009

Where--

Vmax = Maximum allowable operating speed (miles per hour).
Ea = Actual elevation of the outside rail (inches) \4\.
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    \4\ Actual elevation for each 155 foot track segment in the body of 
the curve is determined by averaging the elevation for 10 points through 
the segment at 15.5 foot spacing. If the curve length is less than 155 
feet, average the points through the full length of the body of the 
curve. If Eu exceeds 4 inches, the Vmax formula applies to 
the spirals on both ends of the curve.
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D = Degree of curvature (degrees) \5\.
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    \5\ Degree of curvature is determined by averaging the degree of 
curvature over the same track segment as the elevation.
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3 = 3 inches of unbalance.

    (2) Appendix A includes tables showing maximum allowable operating 
speeds computed in accordance with this formula for various elevations 
and degrees of curvature for track speeds greater than 90 m.p.h.
    (c) For rolling stock meeting the requirements specified in 
paragraph (d) of this section, the maximum operating speed for each 
curve may be determined by the following formula:
[GRAPHIC] [TIFF OMITTED] TR22JN98.008

Where--

Vmax = Maximum allowable operating speed (miles per hour).
Ea = Actual elevation of the outside rail (inches) \4\.
D = Degree of curvature (degrees) \5\.
Eu = Unbalanced elevation (inches).

    (d) Qualified equipment may be operated at curving speeds determined 
by the formula in paragraph (c) of this section, provided each specific 
class of equipment is approved for operation by the Federal Railroad 
Administration and the railroad demonstrates that--
    (1) When positioned on a track with uniform superelevation, 
Ea, reflecting the intended target cant deficiency, 
Eu, no wheel of the equipment unloads to a value of 60 
percent or less of its static value on perfectly level track and, for 
passenger-carrying equipment, the roll angle between the floor of the 
vehicle and the horizontal does not exceed 5.7 degrees.
    (2) When positioned on a track with a uniform 7-inch superelevation, 
no wheel unloads to a value less than 60% of its static value on 
perfectly level track and, for passenger-carrying equipment, the angle, 
measured about the roll axis, between the floor of the vehicle and the 
horizontal does not exceed 8.6 degrees.
    (e) The track owner shall notify the Federal Railroad Administrator 
no less than thirty calendar days prior to any proposed implementation 
of the higher curving speeds allowed when the ``Eu'' term, 
above, will exceed three inches. This notification shall be in writing 
and shall contain, at a minimum, the following information:
    (1) A complete description of the class of equipment involved, 
including

[[Page 125]]

schematic diagrams of the suspension system and the location of the 
center of gravity above top of rail;
    (2) A complete description of the test procedure \6\ and 
instrumentation used to qualify the equipment and the maximum values for 
wheel unloading and roll angles which were observed during testing;
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    \6\ The test procedure may be conducted in a test facility whereby 
all wheels on one side (right or left) of the equipment are raised or 
lowered by six and then seven inches, the vertical wheel loads under 
each wheel are measured and a level is used to record the angle through 
which the floor of the vehicle has been rotated.
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    (3) Procedures or standards in effect which relate to the 
maintenance of the suspension system for the particular class of 
equipment;
    (4) Identification of line segment on which the higher curving 
speeds are proposed to be implemented.
    (f) A track owner, or an operator of a passenger or commuter 
service, who provides passenger or commuter service over trackage of 
more than one track owner with the same class of equipment, may provide 
written notification to the Federal Railroad Administrator with the 
written consent of the other affected track owners.

[63 FR 34029, June 22, 1998; 63 FR 46102, Aug. 28, 1998]