Photo and diagram showing tank cars of same design as UTLX 643593. Union Tank Car Company built UTLX 643593, a U.S. Department of Transportation (DOT) specification 111J100W1 tank car, in late 1992 or early 1993. It was 1 of 52 tank cars (UTLX 643546 through 643597, inclusive) ordered by Olin and designed for TDI product transportation. The certificate of construction for UTLX 643593 and its sister tank cars indicates that these cars were approved for carriage of TDI and Non-regulated commodities and commodities authorized in DOT Part 173 [49 Code of Federal Regulations (CFR) 173] for which there are no other requirements and which are compatible with this design and class of car. Each of these tank cars had a capacity of 20,000 gallons.
<a href="https://en.wikipedia.org/wiki/National_Transportation_Safety_Board" class="extiw" title="w:National Transportation Safety Board">National Transportation Safety Board</a>
U.S. National Transportation Safety Board, Washington, D.C. (2001). <a rel="nofollow" class="external text" href="https://www.ntsb.gov/doclib/reports/2001/HZM0101.pdf">"Rupture of a Railroad Tank Car Containing Hazardous Waste Near Clymers, Indiana; February 18, 1999."</a> Hazardous Materials Accident Report. Report No. NTSB/HZM-01/01. p. 4.