Federal safety investigators said Tuesday they have completed their on-site work regarding the twin oil tank rail derailments on Dec. 30 in Casselton, ND, and will continue their probe in Washington, DC.

North Dakota officials separately pledged to provide any data on the Bakken Shale crude oil that was involved. Lynn Helms, who directs the Department of Mineral Resources (DMR), said he hoped the investigation would ensure safe, future rail shipments.

“I’m a believer that technically it can be done, so my hope is that what comes out of the ongoing study is how to do that safely,” he said. “I don’t think it is fair to blame the product being moved, or the railroad moving it, or the cars it was moving in. It may be a little bit of all three, but there have been at least three incidents where it wasn’t done safely.”

Helms said he didn’t think Bakken crude is inherently more volatile than any other type of crude. In the wake of the explosions the federal government has launched a study to examine the combustibility of Bakken light oil.

In North Dakota, about 750,000 b/d of crude oil is moved in trucks and to date there have been no major incidents, Helms noted. In November, 781,000 b/d, or 71% of the state’s oil production, was moved by rail. “It is safely moved in enormous quantities every day in North Dakota” by truck and rail, Helms said.

In the most recent incident, a crude-bearing train collided with a train carrying grain and derailed, with 21 of the crude rail’s cars and two lead locomotives knocked off a main track near Casselton. Twenty cars were carrying crude; one carried sand. Eighteen of the tank cars were punctured, according to a National Transportation Safety Board (NTSB) preliminary report. Both trains were operated by BNSF Railway.

The NTSB report said a broken axle and two wheels, as well as video recorders, have been shipped to the agency’s materials laboratory for further analysis.

Damage is estimated at $6.1 million, and an initial estimate on the crude oil spilled puts it at 400,000 gallons, the NTSB said. The investigation is being conducted by NTSB and the Federal Railroad Administration (FRA), NTSB’s Pipeline and Hazardous Materials Safety Administration (PHMSA), three railroad-related labor unions and Trinity Rail Car.

Separately on Tuesday, U.S. Department of Transportation officials said new regulations could be in place as soon as 2015 that could require upgraded rail tank cars. The proposed rules are scheduled to be released Nov. 12, with a public comment period through early January 2015, according to PHMSA officials, who noted that the timeline could be altered.

PHMSA earlier this month issued a safety alert on Bakken crude oil, warning that the light, sweet crude may be more flammable than traditional heavy crude oil (see Shale Daily, Jan. 3).

Helms said the state will conduct a separate study of Bakken crude with comparisons to light crude from other areas, given the federal agencies intention now to do so.

“We’re happy that a [PHMSA] study is now ongoing,” said Helms. He noted that a few years ago the Colorado School of Mines conducted an assay comparison of Bakken and West Texas Intermediate crudes for a specific refinery project.

“In that comparison, they came out as virtual twins, but I don’t think that is an adequate amount of data to draw any real conclusions.”

Helms said PHMSA and FRA are conducting a “Bakken Blitz,” by taking samples and comparing Bakken crude with supplies from various other basins, including oilsands supplies, which are also transported by rail.

The federal agencies, said Helms, “have not asked us for the data that we have; authorities in Canada did ask us, and we provided all the data…Once we saw that PHMSA was doing its study, we found no need to duplicate that effort. We decided to offer them all the data we have and support their effort.”

Ultimately, he added, federal and state officials “need to do the science, collect the facts, and see where that leads.”