DOT-111 tank car phaseout urged after derailment

The National Transportation Safety Board has again called for accelerating the planned DOT-111 tank car phaseout after its investigation into a 2024 hazardous materials derailment in North Dakota.

DOT-111 tank car phaseout and DOT-117R concerns

The agency also raised safety concerns about DOT-117R tank cars⁠ used to transport hazardous materials and called for safer placement of hazmat cars within train consists. Those concerns cover both tank car design and the position of hazmat cars in a train.

The derailment occurred on July 5, 2024, in Bordulac, North Dakota. According to the NTSB, 29 cars derailed after a CPKC train traveled over a broken rail⁠. The agency said the broken rail was caused by a track bed collapse linked to a degraded culvert.

Bordulac derailment involved hazardous materials tank cars

The derailed equipment included DOT-111, DOT-112 and DOT-117 tank cars. Methanol released from some of the cars led to a pool fire, and heat from that fire then caused thermal tears in three other derailed tank cars, releasing anhydrous ammonia, a poisonous-by-inhalation gas. In total, nine hazardous materials tank cars were breached during or after the accident. No injuries were reported.

The NTSB said the Bordulac accident was one of the first major hazardous materials release derailments it has investigated since the 2023 Norfolk Southern Railway incident in East Palestine, Ohio. In both cases, according to the agency, DOT-111 tank cars released hazardous materials.

NTSB recommendations target tank car safety

During the Bordulac investigation⁠, the board found that DOT-117R cars have not provided the same safety improvements as newly built DOT-117J cars. DOT-117R cars are retrofitted DOT-111 tank cars with thinner shells. NTSB officials described DOT-111 cars as “dangerously inadequate” because they are highly vulnerable to punctures during derailments.

The board issued 11 new recommendations to the Pipeline and Hazardous Materials Safety Administration, the Association of American Railroads, the American Short Line and Regional Railroad Association, and CPKC. It also reiterated six recommendations to the Federal Railroad Administration and PHMSA, including the recommendation to phase out DOT-111 tank cars.