C.F.R. » Title 49 » CHAPTER I—PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION › SUBCHAPTER C—HAZARDOUS MATERIALS REGULATIONS › PART 179—SPECIFICATIONS FOR TANK CARS › Subpart D—Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW, 115AW, and 117AW)