49 C.F.R. § 299.311
Current through September 30, 2024
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. | 1429 | 1429 | 1429 | 1429 | 1429 | 1429 | 1429 | 1429 |
| Max. | 1454 | 1454 | 1454 | 1454 | 1454 | 1454 | 1454 | 1454 | |
| 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 chord | 38 | 31 | 31 | 14 | 12 | 10 | 8 | 7 |
| 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 chord | 40 | 40 | 40 | 27 | 22 | 18 | 15 | 13 |
| The deviation from uniform crosslevel at any point on tangent and curved track may not be more than- | 50 | 26 | 26 | 22 | 18 | 14 | 9 | 9 | |
| The difference in crosslevel between any two points 2.5 meters (8.2 feet) apart (twist) may not be more than- | 2.5 m | 26 | 26 | 26 | 22 | 18 | 14 | 9 | 9 |
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