OTTAWA -- The navy's decision to retire four venerable warships will mean finding short-term stop-gaps until new vessels are built.

Two of the fleet's three destroyers, HMCS Iroquois and Algonquin, and both supply vessels, HMCS Preserver and HMCS Protecteur, have made their last voyages and will be decommissioned, Vice-Admiral Mark Norman said Friday.

Norman, commander of the Royal Canadian Navy, said the retirements have been in the cards for some time, but other developments speeded up the plans.

In addition to general wear and tear from four decades at sea, Algonquin and Protecteur both were involved in serious accidents recently. Given that they were slated for retirement shortly, there was no point in repairing them.

Algonquin was in a collision in 2013 and Protecteur suffered a major engine room fire last February and had to be towed home from Hawaii. Serious corrosion problems were found in Preserver in recent months.

Iroquois had been slated for retirement next year anyway.

"All of the ships are at or approaching the end of their effective and productive service lives and any further expenditure of time or money in these ships no longer makes sense," Norman said.

The navy is essentially left with a single destroyer, HMCS Athabaskan, 12 Halifax-class frigates and some smaller, coastal defence vessels. The frigates are going through a modernization process and some of them will be docked over the next few years.

Defence analyst Martin Shadwick said losing the four ships will mean less flexibility for the navy in what missions it can take on and how it uses the operational assets it has.

"Our ability to take on commitments both at home and overseas is going to be restrained at least until they get all 12 of the frigates back in service," he said from Toronto.

Norman said he's confident that the navy can meet its commitments.

The destroyers were Cold War sub killers launched in the 1970s. They were refitted in the 1990s as command-and-control ships and area air-defence vessels.

Norman said he expects the frigates can replace them, for the most part, although their anti-aircraft missiles aren't as far-reaching.

"In many respects, a modern, highly capable frigate like we're producing in the Halifax class through the modernization, is as capable in most respects if not more capable than what is now 20-year old technology in the legacy Iroquois class."

The navy is looking at ways to replace the supply ships, which were used to refuel and resupply ships at sea. Replacements aren't due until 2019 at the earliest.

"Options include potential enhancements, or additions, to existing agreements with key allies, as well as some made-in-Canada solutions," Norman said. He wouldn't go into details, but said other navies needing a temporary fix to such a shortage have borrowed vessels or refitted civilian tankers.

The crews of the four warships, about 1,400 sailors in all, will be reassigned. Some will spend months stripping their ships of gear that can be recycled and preparing them for disposal. Others will be retrained for jobs aboard the frigates.

The ultimate fate of the ships lies with Public Works. Norman said he doesn't know if they will be sold for scrap or sunk as artificial reefs.

HMCS Huron, a sister-ship in the destroyer class, was retired in 2000 and sunk as a target in 2007.

While none of the four retiring ships is to sail again, their disposal may take a year or 18 months. Iroquois, however, will be the first to go. She will be formally paid off in January.

NDP defence critic Jack Harris said the decision to decommission the vessels came because of government penny-pinching.

"These ships are being taken out of service because the government can't afford, the navy can't afford to operate them and still try and get their procurement budget going," he said.

"So this government really is putting the screws on, on the navy and the navy's ability to operate in its mandate, and this is the consequence."


HMCS Protecteur

HMCS Protecteur towed

HMCS Iroquois

HMCS Iroquois Canadian warship

HMCS Preserver

HMCS Preserver, a Royal Canadian Navy supply ship