The DOT-117 (TC-117 in Canada) is a type of unpressurized tank car in use on North American railroads. The DOT-117 design was developed in the aftermath of the Lac-Mégantic rail disaster of 2013 in an effort to upgrade the specifications of the then-common DOT-111 and CPC-1232 designs. It was announced on May 1, 2015 by the United States Federal Railroad Administration (FRA) and Canada's Transport Canada (TC). The specifications require that the tank shells be constructed out of steel, with 11-gauge () sheet metal jackets, thick head shields on the ends of the tanks, and improved valves over previous designs.