By David Bamford
The stricken sub is a former British naval vessel
The stricken Canadian patrol submarine, HMCS Chicoutimi, that went adrift off Ireland after an electrical fire knocked out its diesel engines, is a former British Navy vessel already at the centre of controversy because of reports of persistent mechanical failures.
The Chicoutimi - until last Saturday known as HMS Upholder - was the last of four British submarines to be transferred to Canada.
It was on its maiden voyage under a Canadian flag from Faslane in Scotland to Nova Scotia when it ran into difficulties.
The vessel had been due to begin immediate patrol duties off the Canadian east coast.
The four Victoria-class diesel electric-powered submarines - built in the 1980s and early 1990s - had been mothballed since 1994 after the British Royal Navy adopted a policy of maintaining an all-nuclear submarine force.
The three other vessels are in Canada under various stages of refit and trials.
HMCS Corner Brook and HMCS Windsor are based in Halifax in Nova Scotia, and HMCS Victoria is undergoing torpedo system test trials on the Canadian Pacific coast.
The transfer is three years behind schedule because of delays including the need for repairs to cracks in key valves discovered after the vessels were taken out of storage.
The Times newspaper reported last week that the four submarines had been 'dogged by serious malfunctions and corrosion'.
BAE Systems, which was given the contract to prepare the submarines for the Canadian Navy, has declined to comment on the report.
The Canadian government has come under strong criticism in parliament in Ottawa for agreeing in 1998 to buy the four Victoria-class submarines at a cost of US$595m.
The Defence Ministry recently adjusted upwards their estimated annual operating cost from $97m to $121m.
The Defence minister, Bill Graham, has said the cost is worthwhile.
"I do not believe we purchased substandard equipment... the price was very attractive to Canada', Mr Graham said on Tuesday.
'Other ships have had fires in the past and no doubt there will be fires on board our ships in the future... this is something that our professional mariners are capable of managing', he said.
"Despite the delays in getting all four submarines to Canada they represent a vital national asset.
These vessels are cost-effective and essential to the Navy and its mandate to defend Canada and its interests," said Vice-Admiral Bruce MacLean, the commander of Canada's Navy.
The Defence Ministry envisages the vessels will remain in service for 25 years.