HMCS Windsor might be late to its own party.

The Canadian submarine is scheduled to be one of the highlights for international media outlets covering a NATO exercise in Norway this month.

The exercise called Dynamic Mongoose starts June 20 with a tour of French and Norwegian frigates, alongside HMCS Windsor, according to information from NATO officials.

The international event's focus is anti-submarine warfare. It will bring together naval forces from Norway, Germany, Turkey, Canada, the United States, France, the United Kingdom and Spain to train for "future collective defence and crisis response operations," said Barbora Maronkova, a NATO official.

But HMCS Windsor is nearly 5,000 kilometres from the exercise, in Halifax with a broken supercharger.

Problem noticed near St. John's

The sub arrived in Halifax Monday morning, after the crew noticed the problem last week while near St. John's. They were on their way to the NATO exercise, but had to turn back.

One supercharger is connected to each of the submarine's two diesel generators. They are similar to superchargers found in some cars and trucks, increasing the air density in an engine. This allows the engine to run more efficiently and generate more power.

HMCS Windsor has a redundant system with two generators, each with its own supercharger. When one of them failed, the submarine was still able to recharge its batteries using the other generator.

The broken piece is important, but not critical. Capt. Jamie Clarke, commander of Canada's submarine force, stressed nobody was injured and there was no danger posed to the crew. He confirmed there was no smoke or fire caused by the defective supercharger.

Pressure to fix or replace supercharger

The sub is now racing the clock.

The initial plan was to take approximately two weeks to cross the Atlantic to Norway. At its quickest HMCS Windsor could get there in six to 10 days.

That leaves only a few days for submarine maintenance crews to diagnose the problem with the supercharger, fix or replace the part, test the system and prepare for departure.

Navy officials said Saturday they did not have an update yet on the exact cause of the problem, how long it would take to fix or how the submarine's performance was affected.

Each of the four submarines in Canada's fleet has had issues since they were purchased from the British Navy a decade ago.

Problems with submarine fleet

Halifax-based HMCS Windsor is Canada's only fully operational vessel in the four-sub fleet.

On the west coast, HMCS Victoria is being used for training.

HMCS Corner Brook ran aground in 2011 and will be in an extended maintenance period until 2018.

HMCS Chicoutimi may return to service next year, navy officials say. It is out of service because of a problem with some of the welding discovered late last year.