The updated standard includes several enhanced safety features to protect communities along Canada's railways. The TC-117 tank car is required to be constructed as a thermally protected, jacketed tank car with steel that is 9/16th of an inch thick and full head shields. A jacket will be added as an outer cover on the exterior of the shell to keep insulation in place and provide additional strength and reinforcement. These features provide improved puncture resistance, structural strength and fracture resistance.
Thermal protection increases the survivability of tank cars in the event of a fire. The thermal protection required for the TC-117 must be able to withstand exposure to a 100-minute pool fire and a 30-minute jet fuel fire without rupturing.
Full head shields will help protect the ends of the tank car from being punctured by equipment or collisions with adjacent rail cars in the event of excessive end impact or derailment. Previous standards of the DOT-111 tank cars did not require head shields in most cases.
Mandatory top fitting protection will cover the valves on top of the tank car, guarding against damage in the event of an incident.
An enhanced bottom outlet valve must remain closed and not leak during an incident.