After a series of high-profile derailments and subsequent spills, federal officials are calling for the next generation of railway oil tankers to be significantly safer than the current crop.
The National Transportation Safety Board on Monday issued four "urgent recommendations" that would have a bearing on the numerous oil trains that make their way through Minnesota every day.
The board calls for "an aggressive schedule" to replace or retrofit railcars to better protect against heat from fires, as well as improve their ability to withstand impact damage in collisions or derailments.
"We can’t wait a decade for safer rail cars," NTSB Chairman Christopher Hart said. "Crude oil rail traffic is increasing exponentially."
"The industry needs to make this issue a priority and expedite the safety enhancements; otherwise we continue to put our communities at risk," he added.
The board referred to the current stock of DOT-111 tank cars – in common use across North America – which it says "rupture too quickly when exposed to a pool fire caused by a derailment or other accident" – which leads to the oil spilling and igniting.
A study by Minnesota's Department of Public Safety last year revealed that 50 trains carrying more than one million gallons of crude oil pass through the state each week – though this amount may have fallen recently, as production has dropped due to low oil prices.
Trains carrying oil from North Dakota's Bakken oil formation have been involved in multiple derailments in recent years – with one in West Virginia in February sending a "fireball into the sky" when a derailed train caught fire.
A recent study by the Department of Transportation estimates there will be 10 oil train derailments a year in the next two decades, resulting in $4 billion in damage and hundreds of deaths, unless the safety of oil cars is improved significantly.