The DOT Specification 117 tank car must have a thermal protection system. The thermal protection system must:

(a) Conform to §179.18 of this part;

(b) Be equipped with a thermal protection blanket with at least 1⁄2 -inch-thick material that meets §179.18(c) of this part; and

(c) Include a reclosing pressure relief device in accordance with §173.31 of this subchapter.

[81 FR 53957, Aug. 15, 2016]