The problems that caused an Australian navy vessel to lose power twice while delivering aid to Tonga may have been caused by volcanic ash, defense officials have revealed.
HMAS Adelaide suffered a total blackout on January 29 while anchored in Tonga after delivering 88 tonnes of aid.
Back-up power was restored within hours, but a second power outage occurred a day later.
The first failure would be due to the failure of the diesel generator and the second to a gas turbine. A larger technical investigation is underway.
The Defense Department’s chief of marine systems said ash in the air and water after the volcanic eruption could have affected the ship’s seawater cooling system.
Rear Admiral Wendy Malcolm said the Navy had never sailed in such an environment involving a volcanic eruption.
“We believe and we believe it’s entirely possible that this was a key factor in the failure of the generators,” she told a Senate estimates hearing.
“Seawater cooling jammed due to ash and rocks in the water causing the seawater cooling to overheat causing the diesel generations to shut down .”
A sensor fault with the emergency diesel generation where the generator thought it was overspeeding followed afterwards, she said.
“It’s a series of events where the holes in the Swiss cheese lined up,” Rear Admiral Malcolm said.
Navy Chief Michael Noonan said the exact nature of the flaws was still part of an ongoing investigation, but confirmed the flaws did not boil down to a single point.
“We have not seen another electrical failure in HMAS Adelaide and the confidence of the commander and technical staff in the electric propulsion system is high,” the vice admiral said.
“She is fully fit for the mission, she continues to provide support as requested by the Tongan government.”
HMAS Adelaide, stationed for three weeks, remains fully operational and will remain in Tonga until replaced by HMAS Canberra.
The revelation came just hours after the federal government’s $45 billion frigate program was reviewed by senators.
Independent Senator and former submariner Rex Patrick pushed officials over an internal engineering report that raised concerns the ships were slower, noisier and had shorter ranges than expected.
The Navy’s assistant secretary for shipbuilding said specific performance requirements for the ships were yet to be determined, but noted that additional delays and issues would cause the project to be listed as a Project of Concern. .
“If we were to experience any further delay, we would absolutely consider discussing with the government adding this project to the list of projects of concern,” Tony Dalton told senators.
Australian Associated Press