The line towing HMCS Protecteur en route to Hawaii broke Sunday after the ship was taken under tow in "challenging weather conditions" by the U.S. navy cruiser USS Chosin. An engine fire left it stranded Thursday in heavy seas.

Lieutenant Commander Desmond James said the navy is working to get Protecteur back under tow, but does not know yet when that will happen.

The living conditions on board are austere as a result of the damage sustained during the fire - Commodore Bob Auchterlonie

Commodore Bob Auchterlonie, the commander of Canada's Pacific naval fleet, said the destroyer, the USS Michael Murphy, was accompanying Protecteur as the ships tried to make their way at five knots or less [9 km/h] toward Pearl Harbor, 630 km away.

The family of crew members, who were on board Protecteur when the fire broke out, were transferred to the USS Murphy on Saturday.

Auchterlonie says the fleet ocean tug USNS Sioux is also on station near Protecteur should problems arise.

"The slow speed of the towing operation in open seas makes it difficult to make an accurate prediction of how long the overall transit will take," he said. "This is a difficult operation in a challenging environment. Currently the best estimate is that the ships will arrive in Pearl Harbor mid-week."

Ship's company well despite injuries

Auchterlonie says the ship's company is well, and ongoing medical and support services are being provided as required.

About 20 people suffered minor injuries, including dehydration, exhaustion and smoke inhalation when fire broke out in the engine room Thursday around 10:20 p.m. PT as the Protecteur was returning from operational duties with nearly 300 on board.

Aucterlonie says Protecteur has limited electrical power and onboard systems continue to be reactivated in a controlled manner.

"There are reports of significant fire and heat damage to the ship's engine room and considerable heat and smoke damage in surrounding compartments," Auchterlonie said. "The living conditions on board are austere as a result of the damage sustained during the fire."

Auchterlonie called the fire a 'serious event,' because the engine room contained a lot of fuel and combustibles.

He says it significantly damaged the machinery that controls the vessel's propulsion system.

The Protecteur is one of two auxiliary oil replenishment ships in the Canadian navy, both launched in 1969.

Auchterlonie said Saturday it was too early to speculate on the cause of the blaze or how the incident would affect the navy's fleet of supply ships.

The Protecteur, which left on Jan. 6 with HMCS Regina, was carrying 279 crew, 17 family members and two civilian contractors. The vessel was returning to B.C. from extended operations with the U.S. navy in the mid-Pacific.

Crew family on board

The Canadian Department of National Defence said earlier that having family members on board for the final part of such a voyage is a common practice with navy ships returning from extended operations and exercises.

The aging Protecteur was damaged last August in a collision with HMCS Algonquin while en route to Hawaii.

The Algonquin sustained the most significant damage in the accident, but the Protecteur also suffered damage to its front end. Both ships were forced to cancel a planned voyage to Australia and instead return to port in Esquimalt for repairs.

The military announced in October that HMCS Protecteur and its sister supply ship on the East Coast, HMCS Preserver, will be retired in 2015.

Construction of new supply ships are expected to begin in late 2016, with a target of having them in service by 2019-20.

MAP: HMCS Protecteur 630 km northeast of Pearl Harbor