Exhausted naval technicians claim they're battling temperatures of up to 50 degrees Celsius as they work around the clock to repair a power failure that's crippled Australia's largest warship, HMAS Adelaide, in the Pacific.
The ABC has also been told the number of COVID-19 cases on board the vessel known as a "landing helicopter dock" (LHD) is continuing to rise.
"Some of the marine technicians are experiencing heat exhaustion, as they pull 12- to-14-hour days in 50-degree engine rooms," a figure familiar with the situation claims.
A Defence spokesperson said HMAS Adelaide was now operating under normal power generation capabilities and that "critical systems including communications, air-conditions, ventilation, food services and sanitations systems are functional".
It said civilian specialists had arrived in Tonga and were assessing the affected systems on the ship.
"HMAS Adelaide is working in hot, humid and arduous conditions noting Tonga's tropical climate," the spokesperson said.
"HMAS Adelaide's Command Team proactively manage heat and fatigue levels through Ship's Company.
"Defence continues to manage COVID-19 cases on-board HMAS Adelaide. The cases, and close contacts, are being isolated and managed in accordance with COVID-safe protocols."
HMAS Adelaide had been completing a humanitarian mission delivering supplies to tsunami-devastated Tonga when the massive power outages hit the Spanish-built warship last week.
Sources on board the ship told the ABC the ship was "stranded" for a period of time, because of a "total power failure", including the backup power.
Ahead of the LHD's arrival in Tonga, a COVID-19 outbreak emerged on board despite extensive screening of the ship's crew before their departure from Brisbane.
Last week Defence Minister Peter Dutton confirmed 23 positive cases had been detected at sea, but the ABC has been told that figure has now risen to as high as 70.
In an email obtained by the ABC, HMAS Adelaide's commander has described conditions on board as "uncomfortable", but Defence insists "essential functions such as refrigeration and sanitation systems are up and running".
RAAF flights carrying spare parts
RAAF planes are believed to have arrived in Tonga, carrying spare parts needed to fix the problems hampering HMAS Adelaide.
The ABC has been told the complex repair operation involves obtaining spare parts and equipment from "all over Australia including Western Australia" and then flying them to Tonga under strict COVID-19 protocols.
Independent Senator and former Royal Australian Navy submariner Rex Patrick says he's particularly alarmed at the picture emerging from HMAS Adelaide.
"What we are seeing reportedly is that there is a total of power failure," Senator Patrick told the ABC.
"If that is the case, that means there is a single point of failure and you cannot have that on the warship and we will definitely have to look at the details of what happened there, because that is not acceptable."
