After accidents, U.S. railroads seek tougher tank car standards

U.S. railroads on Thursday called on regulators to improve safety standards for tank cars carrying flammable liquids following a boom in transporting oil by rail and a spate of accidents and spills.

Most old tank cars must be phased out, and even new cars will require modifications, the Association of American Railroads said in a letter to the U.S. Pipeline and Hazardous Materials Safety Administration.

The letter came after a train derailed and exploded in western Alabama on Friday, spilling crude oil into a trackside wetland area.

In the summer, a Canadian train derailed in the Quebec town of Lac-Megantic, killing 47 people. The accident prompted a drive for tougher standards for rail car shipments.

Railroads typically do not own the cars or the goods that run on their tracks, but may be liable if accidents occur.

"It's time for a thorough review of the U.S. tank car fleet that moves flammable liquids, particularly considering the recent increase in crude oil traffic," said AAR President Edward Hamberger.

Rapid proliferation of oil-by-train shipments started more than three years as pipeline infrastructure lagged booming U.S. and Canadian crude production.

In the third quarter, crude-by-rail shipments rose 44 percent to 93,312 carloads, equivalent to about 740,000 barrels per day or almost a tenth of U.S. production.

About 92,000 tank cars are moving flammable liquids, with about 78,000 of those requiring retrofit or phase out, the AAR said in its proposal to the PHMSA. It said 14,000 newer tank cars complied with the latest industry safety standards but should still be modified.

Many of the proposed changes are meant to prevent explosions of the kind seen in Alabama on Friday. New cars should include a steel jacket, thermal protection and pressure relief valves, the AAR said.

Even cars built since October 2011, when the rail industry brought in its latest design standards, will need changes, including relief valves and design alterations to prevent spills.

(Reporting by Edward McAllister; Editing by Lisa Von Ahn)