WASHINGTON (Reuters) - Federal investigators will examine whether pressurized gas played a role in the massive blast that followed the derailment of a train carrying crude oil through West Virginia this week, the U.S. Transportation Department said on Thursday.
Questioning the possible role of gas vapors in the West Virginia fire broadens the debate over how to ensure public safety at a time when drastically larger volumes of crude oil are being shipped by rail and roll through cities and towns.
At least two dozen oil tankers jumped a CSX Corp track about 30 miles south of the state capital, Charleston, on Monday, touching off a fireball that sent flames hundreds of feet into the sky.
The U.S. Transportation Department said it has an investigator at the site to take samples of crude once the wreckage stops burning.
“We will measure vapor pressure in the tank cars that derailed in West Virginia,” said department spokeswoman Suzanne Emmerling.
Some experts say the nature of the explosion, which saw a dense cloud of smoke and flame soaring upwards, could be explained by the presence of highly pressurized gas trapped in crude oil moving in the rail cars.
“Vapor pressure could be a factor,” said Andre Lemieux of the Canadian Crude Quality Technical Association, a trade group which is helping the Canadian government adopt crude oil quality tests.
The American Petroleum Institute, the leading voice for the oil industry, declined to comment on whether high vapor pressure might have played a role in West Virginia.
“What we need to do now is allow the accident investigators to do their jobs,” said Brian Straessle, a spokesman for the trade group.
In the past twelve months, API and the North Dakota Petroleum Council have argued that the dangers of vapor pressure are exaggerated, citing self-funded studies that indicate vapor pressure readings are safe.
Starting in April, North Dakota oil producers will have to tame vapor pressure dangers as part of a statewide plan to reduce dangers on the tracks.
But there is no national standard to control the risk of dangerous gas in oil train cargo.
The Transportation Department declined to govern vapor pressure in a national oil train safety plan conceived last summer. That plan is now with the White House for final review.
The proposal would have oil trains fitted with advanced braking systems to prevent pileups and tougher shells akin to those carrying volatile propane gas on the tracks.
The question of whether gas vapors make oil shipments more prone to detonate has been kept on the margins of the U.S. debate over transporting oil by rail.
The oil train sector has thrived in recent years, pushed by a crude oil renaissance in North Dakota’s Bakken region.
Of the roughly 1.2 million barrels of crude oil produced in North Dakota daily, more than 60 percent of that fuel reaches refineries by rail, typically in 100-tanker unit trains that can stretch a mile long.
Rail and tank car industry leaders have warned that Bakken fuel is uncommonly volatile and that toughened rail cars are needed to control the risk of explosion.
Moving Bakken crude in containers akin to those that haul propane gas on the tracks, as the DOT has outlined, would be one way to mitigate dangers and “the likelihood of seeing... mushroom clouds going up into the sky,” Bob Fronczak, the Association of American Railroad’s hazmat chief, told a safety hearing in April.
Fronczak declined to comment on Thursday. An AAR spokesman said the trade group backed a strong oil train safety plan and looked forward to seeing a final proposal due in May.
Tougher cars and advanced brakes will likely mitigate future oil train mishaps but investigators are right to scrutinize every risk that could have contributed to the West Virginia mishap, said Cynthia Quarterman who recently resigned as head of the DOT’s PHMSA.
“Any hazmat regulator or investigator worth his salt would gather as much data as possible,” she said.
Reporting By Patrick Rucker; Ernest Scheyder contributed from Williston, North Dakota; editing by Andrew Hay