The exact cause of a 2023 fire aboard a research vessel in Alaska has eluded investigators from the National Transportation Safety Board (NTSB), which issued its final report on the incident on Tuesday.
On January 19, 2023, small vessel Qualifier 105 was being stored ashore for the winter in the Northern Enterprises Boat Yard in Homer, Alaska when a fire started in a stateroom below the main deck. The local fire department extinguished the fire and no pollution or injuries were reported.
The owners Support Vessels of Alaska—which used the 105-foot-long vessel for marine survey, oceanographic research, environmental clean-up, housing and private charters—declared the vessel a loss of $1.2 million.
While welders were on board performing aluminum hot work before the fire, investigators ruled out the hot work as a source of the fire, as there were no signs of a fire after or while conducting the work. Investigators concluded the fire was caused by an undetermined electrical source that ignited a stateroom ceiling. The substantial use of combustible materials for stateroom ceilings and bulkheads throughout the vessel’s accommodation spaces contributed to the extent of the fire damage.
Although investigators could not definitively determine that stray welding current caused the fire, the NTSB report highlighted precautions to take for stray welding current.
“Stray welding current is a fault condition in which current goes through unintended conductors and back to the return terminal of a welding machine; it can cause fires by overheating wires,” the report said. “To avoid potential fires caused from stray welding current, maintenance personnel, owners, and operators should follow industry practice to place the work clamp (the return current clamp) of the welding machine as close as possible to the point of welding.”