49 C.F.R. § 299.313

Current through September 30, 2024

Section 299.313 - Track geometry; performance based

(a) For all track of Class H4 and above, vibration in the lateral and vertical directions measured on the carbody of a vehicle representative of the service fleet traveling at a speed no less than 10 km/h (6.2 mph) below the maximum speed permitted for the class of track, shall not exceed the limits prescribed in the following table:

Table 1 to Paragraph (a)

Carbody acceleration limits ^{1 2}
Lateral vibration³	Vertical vibration³
[LESS THAN EQUAL TO] 0.35 g peak-to-peak	[LESS THAN EQUAL TO] 0.45g peak-to-peak
1 sec window	1 sec window
excluding peaks [LESS THAN] 50 msec	excluding peaks [LESS THAN] 50 msec

¹ Carbody accelerations in the vertical and lateral directions shall be measured by accelerometers oriented and located in accordance with § 299.337(c)(3) .

² Acceleration measurements shall be processed through an LPF with a minimum cut-off frequency of 10 Hz. The sample rate for acceleration data shall be at least 200 samples per second.

³ Peak-to-peak accelerations shall be measured as the algebraic difference between the two extreme values of measured acceleration in any 1-second time period, excluding any peak lasting less than 50 milliseconds.

(b) If the carbody acceleration requirements are not met on a segment of track, the segment of track is to be reclassified to the next lower Class of track for which it does meet the requirements of this part.

49 C.F.R. §299.313

85 FR 69731, 12/3/2020