Studies dating back to 1991 have identified a serious design defect in a common train car, the DOT-111. The metal shell on these cars is not strong enough to withstand derailments. Hard collisions can punch holes in the car's tanks, spilling potentially dangerous chemicals onto the tracks.
A major derailment ignited a giant inferno this summer after DOT-111s spilled ethanol, focusing more attention on this dangerous design defect . The fire occurred after 19 train cars derailed near a crossing. Of the 19 cars, 13 were DOT-111s loaded with 30,000 gallons of ethanol each. The crash punctured the DOT-111s and the ethanol exploded into a massive blaze. A woman died in the fire and her family suffered serious injuries.
This was not an isolated incident: a report based on federal accident data revealed that DOT-111 punctures were involved in 40 severe incidents since 2000. Federal regulators confronted train companies and the chemical companies who traditionally lease and operate the tankers.
Although the train and chemical companies acknowledge the design flaw and have committed to redesigning a safer car for future operations, they insist that retrofitting the current DOT-111s would be too expensive. Between 30,000 and 45,000 would continue to operate with the defective design. Some of the cars are new and would remain in service for quite some time.
The National Transportation Safety Board wants to apply higher standards to all tankers. It said that DOT-111s "can almost always be expected to breach in derailments that involve pileups or multiple car-to-car impacts." Another federal agency, the Pipeline and Hazardous Materials Safety Administration, is considering the matter.
Source: My Fox Phoenix, "Common type of rail car has dangerous design flaw," Jason Keyser, Sept. 12, 2012