Liquid-hydrogen tank car

A liquid hydrogen tank car, also called liquid hydrogen tank wagon or liquid hydrogen tanker wagon is a railroad tank car designed to carry cryogenic liquid hydrogen (LH2). LH2 tank cars with a capacity of 17000 lb are used for transcontinental transport.

Design
The pressure within the tank is 25 psi or lower with a temperature below 20.27 K (−423.17 °F) and a boil-off rate of 0.3% to 0.6% per day The tank is double walled like a vacuum flask with multi-layer insulation, with the valves and fittings enclosed in a cabinet at the lower side or end of the car.

Classes
Cryogenic liquid tank cars in the USA are classified as follows:
 * DOT-113 tank cars (Cryogenic liquid tank cars)
 * AAR-204W tank cars (Cryogenic liquid tank cars)
 * AAR-204XT (Inside boxcar)