49 CFR §179.202-12

1. (a)Approval. Design, testing, and modeling results must be reviewed and approved by the Associate Administrator for Railroad Safety/Chief Safety Officer, Federal Railroad Administration (FRA), 1200 New Jersey Ave. SE., Washington, DC 20590.
2. (b)Approval to operate at 286,000 gross rail load (GRL). In addition to the requirements of paragraph (a) of this section, a tank car may be loaded to a gross weight on rail of up to 286,000 pounds (129,727 kg) upon approval by the Associate Administrator for Safety, Federal Railroad Administration (FRA). See § 179.13.
3. (c)Puncture resistance.
   1. (1)Minimum side impact speed: 12 mph when impacted at the longitudinal and vertical center of the shell by a rigid 12-inch by 12-inch indenter with a weight of 286,000 pounds.
   2. (2)Minimum head impact speed: 18 mph when impacted at the center of the head by a rigid 12-inch by 12-inch indenter with a weight of 286,000 pounds.
4. (d)Thermal protection systems. The tank car must be equipped with a thermal protection system. The thermal protection system must be equivalent to the performance standard prescribed in § 179.18 and include a reclosing pressure relief device in accordance with § 173.31 of this subchapter.
5. (e)Bottom outlet. If the tank car is equipped with a bottom outlet, the handle must be removed prior to train movement or be designed with protection safety system(s) to prevent unintended actuation during train accident scenarios.
6. (f)Top fittings protection. The tank car tank must be equipped with top fittings protection conforming to AAR Specifications for Tank Cars, appendix E paragraph 10.2.1 (IBR, see § 171.7 of this subchapter).