CFR / 
Title 49
 / Part 179
 / 
Sec. 179.202-5 Tank head puncture resistance system.
The DOT-117 specification tank car must have a tank head puncture resistance system in conformance with Sec. 179.16(c). The full height head shields
must have a minimum thickness of \1/2\ inch.
[80 FR 26749, May 8, 2015]