NTSB Reports DOT-111 Phaseout Urgency After ND Derailment

WASHINGTON, D.C. – The National Transportation Safety Board (NTSB) has renewed a longstanding safety recommendation to speed up the elimination of DOT‑111 tank cars from hazardous materials service, following its investigation of a July 5, 2024 derailment in Bordulac, North Dakota. The accident, involving 29 CPKC rail cars—17 carrying hazardous materials—led to a pool fire and toxic gas release, breaching nine tank cars in total. No injuries were reported, but the board highlighted that heat‑induced thermal tears on DOT‑117R cars released anhydrous ammonia, a poisonous-by-inhalation hazard.

What Does This Regulation Cover?

The NTSB reiterated that DOT‑111 tank cars, long known to be vulnerable to puncture and rupture in derailments, should be phased out ahead of the current 2029 federal deadline for flammable liquids. Additionally, the board raised concerns about the performance of DOT‑117R cars—retrofitted versions of older cars that meet newer safety standards—after three of them tore open due to pool fire exposure, releasing toxic gas. The recommendations also call for safer placement of hazardous materials cars within train consists, aiming to reduce the risk of cascading releases during an accident. The agency did not issue a new proposed timeline for the DOT‑111 phaseout, leaving the acceleration target unspecified.

Key Regulatory Data

How Does This Compare to Global Standards?

Canada completed a mandatory phaseout of unprotected DOT‑111 tank cars for crude oil and ethanol by 2020, and for other flammable liquids by 2025, under Transport Canada’s TC‑117 standard—four years ahead of the U.S. deadline (Source: Transport Canada, 2018). Europe’s RID regulation has long required higher‑integrity pressure‑car designs for toxic gases, and many EU member states do not permit anhydrous ammonia to be carried in retrofitted cars at all. The NTSB’s concern over DOT‑117R cars therefore pushes U.S. policy closer to these international norms, though no concrete proposal for an accelerated U.S. phaseout date has yet been laid before regulators. Independent verification of whether the U.S. Pipeline and Hazardous Materials Safety Administration will act on this recommendation was not available at time of publication.

Editor’s Analysis

The NTSB’s renewed push comes as the broader freight rail sector faces a technology shift. Autonomous battery‑electric railcars, such as those developed by Parallel Systems, move freight in small, software‑orchestrated platoons rather than long, diesel‑hauled trains. If adopted for hazmat transport, such architectures could reduce the scale of a single failure—fewer cars derailing at once and lower thermal loads in a fire. Meanwhile, industry partnerships like Forsee Power with Wabtec on battery‑electric locomotive platforms signal that zero‑emission, more modular freight options are gaining supply‑chain traction (Source: Robotics & Automation News, 2026; IM Mining, 2026). These trends may eventually reframe the tank‑car debate from retrofitting legacy fleets to entirely new transport modes.

FAQ

Q: Why did the NTSB flag DOT‑117R cars if they already meet U.S. safety standards?
A: The DOT‑117R is a retrofit of older DOT‑111 or DOT‑112 shells with thicker tank jackets, but the Bordulac investigation found that pool‑fire heat caused thermal tears and toxic gas release, indicating that retrofit designs may still be vulnerable under extreme conditions.

Q: When will the U.S. phase out DOT‑111 tank cars completely?
A: Under current federal regulations, most DOT‑111 cars used for flammable liquids must be phased out by 2029. The NTSB has recommended an accelerated timeline, but no new date has been officially proposed or confirmed.

Q: How might autonomous rail technology affect hazardous materials safety?
A: Smaller, autonomous platoons could reduce the number of hazmat cars concentrated in a single train, lowering the severity of a derailment. However, regulatory frameworks for autonomous freight rail are still under development, and this approach has not been officially adopted by any Class I railroad.