Forum reporter Amy Dalrymple is reporting that the oil involved in the Heimdal derailment was below the conditioning threshold set by state regulators which went into law on April 1st.
“Oil from the Tioga rail facility has tested at 12.44 psi, 11.08 psi and 11.18 psi, according to April tests submitted by Hess to the Department of Mineral Resources,” Dalrymple reports. The state requirement is no more than 13.7 pounds per square inch.
I can add to Dalrymple’s report that the vapor pressure for the oil that was actually on the Heimdal train was well below even those tests. Below are the FRA reports from the Heimdal train.
As you can see, the vapor pressure of the oil was tested at 10.83 psi.
That’s almost 21 percent lower than the threshold set by the state. By comparison, the gasoline you use in your car tops out at under 15 psi.
Unfortunately, this conditioned oil was being transported in an older style tanker car that has long been criticized and is slated to be phased out because of exactly these sort of safety concerns.
Fewer derailments, and tanker cars less prone to rupture upon derailment, would go a long way toward solving this problem.