49 C.F.R. § 299.311

Current through October 31, 2024
Section 299.311 - Track geometry; general

If the values listed in the following table are exceeded, the railroad shall initiate remedial action. A reduction in operating speed so that the condition complies with the limits listed for a lower speed shall constitute bringing the track into compliance.

Table 1 to § 299.311

Track geometry parameter (millimeter (mm))Track class H0 H1 H2 H3 H4 H5 H6 H7
Gauge is measured between the heads of the rails at right angles to the rails in a plane 14 mm (0.55 inches) below the top of the rail head and may not exceed-Min.14291429142914291429142914291429
Max.14541454145414541454145414541454
The deviation from uniformity1 of the mid-chord offset on either rail for a 10 meter (m) chord (alignment) may not be more than-10 m chord38313114121087
The deviation from uniform profile on either rail at the mid-ordinate of a 10 m chord (surface) may not be more than-10 m chord4040402722181513
The deviation from uniform crosslevel at any point on tangent and curved track may not be more than-50262622181499
The difference in crosslevel between any two points 2.5 meters (8.2 feet) apart (twist) may not be more than-2.5 m26262622181499

1 Uniformity for alignment at any point along the track is established by averaging the measured mid-chord offset values for a 10 m (32.8 feet) chord for nine consecutive points that are centered around that point and spaced at 2.5 m (8.2 feet) intervals.

49 C.F.R. §299.311

85 FR 69731 , 12/3/2020