Key facts
- The NTSB concluded that a 2024 North Dakota derailment demonstrated the need to replace flawed DOT-111 tank cars.
- The derailment, which occurred near Bordulac, North Dakota, involved methanol and anhydrous ammonia.
- The NTSB has been urging the replacement of DOT-111 tank cars for decades due to their tendency to rupture in crashes.
- The agency recommended changes to train assembly to prevent toxic chemicals from being placed near flammable ones.
- Congress mandated the replacement of these cars for flammable liquids by 2029, but they may still be used for other hazardous materials.
The National Transportation Safety Board (NTSB) has concluded that a fiery derailment in North Dakota in July 2024 underscored the long-standing need to replace flawed DOT-111 tank cars. In its final report, released Thursday, the NTSB stated that these "workhorse" tank cars are overdue for replacement due to their tendency to rupture in crashes, which magnifies the impact of hazardous chemical leaks and fires.
The derailment, which occurred just outside Bordulac, North Dakota, was caused by a collapsed culvert that broke a rail. However, the NTSB emphasized that the leak-prone nature of the DOT-111 cars significantly worsened the incident. Five tank cars breached, spilling methanol that subsequently caught fire, leading to the breach of three cars carrying anhydrous ammonia. The report also noted that some upgraded tank cars developed since the 1990s still possess thin outer shells, making them susceptible to rupture.
The NTSB has been advocating for the elimination of DOT-111 cars for hazardous materials since the 1990s. While Congress mandated their replacement for hauling flammable liquids by 2029, they can still be used for other hazardous materials. The agency also recommended that railroads alter train assembly practices to prevent flammable liquids from being positioned near toxic chemicals that could be inhaled if released.
In the North Dakota incident, 29 of the 151 cars derailed. Fortunately, only two homes were voluntarily evacuated, and no injuries were reported in the derailment itself, though some cleanup workers sought treatment for health issues related to anhydrous ammonia exposure. CPKC spokesman Patrick Waldron stated the railroad is reviewing the report, while other relevant agencies did not immediately comment.