Overheated wheel bearing likely cause of US Ohio train derailment – NTSB

HOUSTON (ICIS)–The US National Transportation Safety Board (NTSB) continues to investigate the cause of a Norfolk Southern train derailment in Ohio on 3 February but said in a preliminary report released on Thursday that a wheel bearing on the 23rd car of the train overheated and failed moments before the derailment.

The report did not contain a probable cause, which will come at the end of the investigation, but contained facts collected during the on-scene portion of the investigation.

NTSB officials said during a media availability on Thursday that they will hold a rare investigative field hearing later this year in East Palestine, where they will question invited witnesses.

The goals of the hearing will be to inform the public, gain factual information from witnesses, discuss possible solutions and build consensus for change.

PRELIMINARY REPORT
The train, comprised of two head-end locomotives and 149 railcars with a distributed power locomotive between railcars 109 and 110, included 20 placarded hazardous material railcars carrying combustible liquids, flammable liquids and flammable gas, including vinyl chloride monomer (VCM).

The train was headed east from Madison, Illinois, to Conway, Pennsylvania, at the time of the derailment in East Palestine, Ohio.

NTSB investigators said the train was using dynamic braking, which uses electronic traction motors as generators, slowing the train and dissipating mechanical energy as heat.

The Norfolk Southern rail network is equipped with wayside defect detectors, or hot bearing detectors (HBDs) systems, and the train passed three HBDs immediately prior to the derailment.

The third reading showed the bearing with a temperature of 253°F (122.8°C) above ambient temperature on the 23rd railcar as the train was on the east side of East Palestine. The HBD transmitted a critical audible alarm to the crew alerting them of the need to stop the train and inspect the hot axle.

The derailment occurred immediately thereafter.

The Association of American Railroads (AAR), the trade group for the railroad industry, said railroads are following the investigation closely.

“NTSB’s deliberate and methodical approach under these challenging circumstances has been essential to establishing independent, credible findings into the cause of the accident in East Palestine,” Ian Jefferies, AAR president and CEO, said. “As an industry, railroads will use this initial report in shaping a thoughtful, fact-driven approach to prevent another similar accident before it can occur elsewhere.”

“As stakeholders review this preliminary report, the railroads will continue to follow this ongoing investigation closely and look forward to reviewing NTSB’s final report,” Jefferies said. “We share a singular mission of taking meaningful steps to further improve safety.”

The American Chemistry Council (ACC), a trade group for the chemical industry, said the derailment shows the need for a constant focus on safety.

“People are understandably concerned and question why we ship chemicals, including those that are classified as hazardous materials,” Chris Jahn, ACC president and CEO, said. “We ship them because they are needed across the country and essential to everyday life. Chemicals are critical to providing safe drinking water, ensuring a plentiful food supply, producing life-saving medicines and medical equipment, and generating many types of energy.”

“We must strive to meet the daily needs of the nation while delivering materials safely,” Jahn said.

After the press conference, the ACC said it supports the work of the NTSB.

“We value the NTSB’s role in supporting transportation safety,” the ACC said in a statement. “The Board’s independent investigations of accidents and recommendations are very influential and a catalyst for safety improvements. While we understand the investigation is still ongoing with more findings to come, we will review the preliminary report carefully and look for potential lessons that can help prevent future accidents.”

In the US, chemical railcar loadings represent about 20% of chemical transportation by tonnage, with trucks, barges and pipelines carrying the rest.

In Canada, chemical producers rely on rail to ship more than 70% of their products, with some exclusively using rail.