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NTSB: Engine Failure leads to fire aboard offshore supply vessel

The National Transportation Safety Board of the United States (NTSB) has published a report into a diesel generator engine failure and subsequent fire aboard an offshore supply vessel (OSV) in December 2020. Further information here.

What happened

Crew on a OSV ​at anchor were troubleshooting speed variation issues related to two of the engines driving the vessel’s generators.  This involved replacement and calibration of several electrical components and multiple engine restarts. When later carrying the vessel’s electrical load, one of these two engines suffered catastrophic mechanical failure. A cylinder connecting rod was ejected through the engine crankcase while the engine was running.  The ejection of the connecting rod allowed atomized oil to be released from the engine and ignite, starting a fire in the engine room.

What was the cause?

The NTSB determined the probable cause of the diesel generator engine failure was a cylinder’s connecting rod bearing adhering to the crankshaft.  In short – it seized up. This led to the ejection of the connecting rod and catastrophic damage to the engine.

Lessons learned

The NTSB noted that:

“The crew effectively contained the spread of a fire by removing fuel and oxygen sources.

Vessel crews should familiarize themselves and train frequently on machinery, fuel oil, lube oil, and ventilation shutoff systems to quickly act to contain and suppress engine room fires before they can spread to other spaces and/or cause a loss of propulsion and electrical power.”

What went right?

  • The crew’s quick and effective actions to prevent the spread of the fire resulted in the fire extinguishing itself without putting crewmembers at risk;
  • The crew isolated the fire before it could spread throughout the vessel;
  • There was no pollution and no injuries to the sixteen crew.

There was, however, over $3 million worth of damage to the vessel.

Members may wish to refer to:

Safety Event

Published: 10 February 2022
Download: IMCA SF 04/22

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