The type of rail tank car that ruptured near Superior, Wis., this week, releasing toxic chemicals and causing the evacuation of much of Superior and Duluth, Minn., has been criticized in the past by both a federal safety agency and a railroad trade association.
The car has thinner walls and provides less protection against puncture and fire than some other tank cars used to haul hazardous materials.
The safety of cars used to haul hazardous materials is expected to come under scrutiny by the National Transportation Safety Board as the investigation into the accident continues.
As that investigation began yesterday, Molly Hart, spokeswoman for the Federal Railroad Administration, confirmed that Burlington Northern had inspected the track the day before the accident and used sophisticated equipment to check it three weeks ago. Agency inspectors checked it in January and all three inspections found no problems, she said.
John Stoner, spokesman for the Research and Special Programs Administration of the U.S. Department of Transportation, called the tank car that ruptured, known as a 111A, "the industry workhorse." Stoner's agency regulates railroad transportation of hazardous materials.
But last July, James Kolstad, then the chairman of the safety board, testified before Congress that it had been "evident for many years" that the tanker was not adequate for safely hauling some hazardous materials.
The Association of American Railroads, the trade association for the major freight haulers and Amtrak, has been trying for more than two years to convince companies to put the chemicals in better tanker cars, said Carol Perkins, an association spokeswoman. She said her organization was pushing for a tanker that has thicker walls and no bottom outlets for the materials.
Meanwhile, masked crews carefully pumped toxic chemicals and explosive propane from the derailed tankers yesterday.
Officials said the spill probably would have no long-term effect on people or wildlife.