It's the mileage, not the years: Military says it plans to keep subs afloat past retirement dates

The Canadian navy has found a very creative way to keep its second-hand submarines afloat until the late 2030s and early 2040s — a plan that emphasizes maintenance over age in predicting how long the vessels can remain seaworthy.

The plan — according to a newly-released briefing note prepared in the run-up to the release of the Liberal government's marquee defence policy — would not see HMCS Victoria decommissioned until the end of 2042, giving the warship over 45 years service in Canada.

That estimate does not include the time the boat served with Britain's Royal Navy, which would add at least a decade to its working life.

The retirements of the other submarines — HMCS Chicoutimi, HMCS Windsor and HMCS Corner Brook — would be staggered throughout the 2030s, with Windsor being the first to go in 2033.

"The [Victoria Class Submarines] are a well-designed and solidly constructed class of modern conventional submarines that have had an unusual life since entering service with the [Royal Navy] in the early 1990s," said the August 2016 briefing analysis, recently obtained by Conservative Party researchers. "'While chronologically 20 years older, they have not been operated extensively during that time."

The boats were first constructed for the Royal Navy in the 1980s, but Britain decided to sell them when the government of the day made the policy decision to operate only nuclear-powered submarines.

One aspect of the Liberal defence policy, released in June 2017, that has puzzled military experts and opposition critics alike was its assumption that the submarines — which have had a tortured technical history that includes one fatal fire — will remain in service until at least the 2040s.

The briefing note spells out in detail — and for the first time publicly — how the navy intends to squeeze more life out of boats it was supposed to start retiring in four years.

It was originally envisioned, the briefing said, that the Victoria-Class submarines would retire one at a time, beginning in 2024.

The report argues it is possible to operate the submarines beyond their expected working lives if the military assesses the "material state" of each boat rather than following "a simplistic calendar driven" evaluation of their operational condition.

In others words, the report argues that what matters most is not how old the submarines are, but rather how hard have they been driven and how well have they been maintained.

The submarines operate on what's called a "6-2 schedule" — six years of service at sea followed by two years of deep maintenance before returning to duty.

The briefing note proposes that the boats do nine years of service and then go into a longer refurbishment of up to three years. The submarines would need a full life-extension overhaul in addition to the extended maintenance plan.

As evidence to support the plan, the briefing note to senior defence officials pointed to a 2013 study of the Victoria-Class submarines — which said that "although there are numerous technical and supportability challenges, there was no single obstacle precluding a life extension of up to 12 years."

'Lower expectations'

The briefing offers one note of caution, however: "It is reasonable to assume that operational availability will decrease as the submarine ages."

The briefing note predicted higher maintenance and sustainment costs as the boats get older. To save money, it said, the navy might have to lower expectations of what the boats can do.

The existing plan "assumed that there would be no relaxation of operational performance requirements, although in fact some discretion by the Operational Requirements Authority in this regard may be feasible as a cost saving measure," said the note.

Conservative defence critic James Bezan said he was astounded by the plan to stretch out the operational life of the subs. He said he doesn't blame the naval planners who drew up the document — but he does hold the Liberal government accountable, arguing it must have ordered the Department of National Defence to give it some justification for putting off the purchase of new submarines.

"It is ridiculous," Bezan said. "There was potential for some political direction on how this was written."

In an interview with CBC News at the end of last year, the commander of the navy, Vice-Admiral Art McDonald, defended the plan to extend the life of the boats, saying he had full confidence in the "pretty resourceful and capable" submarine engineering community.

The defence policy, he said, "directed us to operate and modernize" the submarine fleet and he's confident it can be done safely.

"We know there is still excellent life in the Victoria-class submarine," McDonald told CBC News. "I've seen that personally as an outsider who has come into the program and taken a look at it."

The focus of the subs' modernization project — which was in the early stages of being developed when the pandemic hit back in late winter — will be on survivability and making the submarines more livable for crew members.

"We're going to be able to operate those boats into the 2030s, but to do that we have to continue with the routine investments we've made and modernize, as was directed" by the defence policy, McDonald said.

Not everything can be replaced

A series of assessments was conducted between 2008 and 2014. The defence department's naval board, which is charged with planning the future shape of the fleet, met in November 2014 to study the life expectancy of the second-hand boats. 

"While it is considered unrealistic to predict the material state of 40-year-old platforms, 20 years into the future, certain items such as the pressure hull and main motor will require additional monitoring and maintenance above the current regime, since unpredicted degradation in such areas may not be cost effective to repair and mitigate," said the 2016 briefing note.

And that's the problem with the life-extension plan, said Bezan: some key parts of a submarine — such as the pressure hull and the engines — can't be upgraded. He also pointed to how the submarine fleet had "zero days at sea" in 2019 because all of the vessels were tied up for maintenance.

The analysis, Bezan said, shows that the Liberal government should immediately begin looking for a replacement for the submarines — something the previous Conservative government was in the process of doing when it was defeated in 2015.

The options that were discussed before the election, he said, included partnering with the Australians — who were in the process of acquiring their own submarine replacements — or buying an off-the-shelf design for inclusion in the federal shipbuilding strategy. None of those ideas got very far before the election, he added.