NTSB’s learnings from Hyndman derailment

BRAKE IN PROCEEDINGS

INVESTIGATION • NTSB’S REPORT ON THE 2017 HYNDMAN DERAILMENT HIGHLIGHTS THE NEED FOR RAILROADS TO TAKE ACTION TO DEVELOP RISK REDUCTION AND SYSTEM SAFETY PLANS

THE US NATIONAL Transportation Safety Board (NTSB) has concluded its investigation of the August 2017 derailment of a CSX Transportation freight train on a grade crossing near Hyndman, Pennsylvania and determined that the probable cause was the inappropriate use of hand brakes on empty rail cars to control the train’s speed, together with the placement of blocks of empty cars at the front of the consist.

The train consisted of five locomotives and 178 cars, of which 50 were empty. Of the loaded cars, 70 contained hazardous materials and the train was classified as a Hazardous Material Key Train. Three derailed tank cars with hazardous materials were breached in the derailment, leading to a fire that damaged three nearby homes. While there were no injuries or fatalities, a one-mile evacuation zone was established, affecting some 1,000 residents, and several grade crossings were closed.

It was determined that the fire started in a propane tank car that was involved in the derailment and had been punctured in several places, causing response personnel to move away from the site. Molten sulphur spilled from another car, which was also burning, and molten asphalt spilled from an open bottom outlet valve on another. Other hazmat cars contained ethanol, heptane, sodium chlorate and phosphoric acid.

HOW IT HAPPENED NTSB’s investigation found that, on the day prior to the derailment, the train’s engineer had experienced an increase in brake pipe pressure, indicating an air leak. The train was stopped and the conductor applied hand brakes on 58 cars, as required by CSX operating rules. The conductor also found an air leak on one car towards the rear of the train and CSB sent two mechanics to fix the problem. A relief crew took over and told CSX’s office that they would release the hand brakes when the train reached the bottom of the grade; NTSB notes that CSX is the only Class 1 railroad that allows its engineers to use hand brakes to control a train’s downhill descent.

In the event, the train’s crew found they needed to release 25 of the hand brakes before the train would move. The train then continued downhill at a speed of between 20 and 30 mph until the 35th car derailed on a grade crossing.

NTSB found that the placement of blocks of empty rail cars at the front of the train consist generated elevated longitudinal forces and increased lateral forces at the wheel/rail interface and tread build-up on the 35th car. NTSB also says that an effective risk reduction or system safety programme would have likely led CSX to identify the risks that led to the accident and provide an opportunity to mitigate those risks.

The Federal Railroad Administration’s (FRA) recently enacted requirement for risk reduction and system safety programmes provides a similar opportunity, although NTSB says FRA has not yet provided sufficient guidance to railroads on the development of those programmes, which the railroads are due to submit to FRA for review and approval by 16 August 2021.

NTSB also says: “The railroad industry would benefit from an industry-led effort to develop best practices and implementation guidance for risk reduction programmes.” One of the recommendations arising from its investigation is that the Association of American Railroads (AAR) should take a lead in this process.

NTSB also recommends that CSX revise its rules for building train consists so that large blocks of empty cars are placed towards the rear of the train, and to prohibit the use of hand brakes on empty cars for the purpose of controlling train movement in grade territory.

NTSB’s investigation also highlighted some hidden hazards caused by fire-exposed jacketed pressure tank cars and has asked the Security and Emergency Response Training Center to look at the issue.

NTSB’S INVESTIGATION REVEALED AREAS