These submarines initially suffered from serious electrical problems and were beset by mechanical operational incidents that limited their active service and the scope of their deployments.

In the late 1970s the United Kingdom Ministry of Defence (MoD) proposed a diesel-electric submarine design to replace the Oberon class.

They are equipped with two Paxman Valenta 1600 RPS SZ diesel engines, each driving a 1.4-megawatt (1,900 hp) GEC electric alternator.

[3][4] In British service, the submarines were supplied with up to 18 Marconi Mk 24 Tigerfish Mod 2 torpedoes; they were also capable of using UGM-84 Sub-Harpoon missiles.

[8] As built, the Upholder class was equipped with the Kelvin Hughes Type 1007 I-band radar for navigational purposes.

The Pakistan Navy's research team, comprising three admirals, visited Sweden, China, France, and the United Kingdom.

Original plans were to acquire the submarines from Sweden but later the acquisition of either the British Upholders or the French Agosta class was recommended.

During this time, Admiral Saeed Khan, the Chief of Naval Staff (CNS), had strongly suggested Upholder class vessels, but the Bhutto administration chose French technology for several political and technical reasons.

[16] The Canadian National Defence White Paper of 1994 stated the intent to explore the purchase of the Upholder class from the UK.

[17] The choice faced opposition and the price of $1 billion that the MoD demanded stalled the decision by the Cabinet of Canada to go ahead with the purchase.

The lease payments were part of a barter agreement for the continued access by the UK to Canadian Forces bases Wainwright, Suffield, and Goose Bay.

[18] Although the Canadian government touted the $750 million CAD[20] procurement as a bargain, there have been arguments over the quality of the submarines with some suggestions that the purchase price will be at least spent again putting things right.

Some Canadian opposition parties demanded that the British government fund any further costs, since it is widely believed that the submarines deteriorated while in storage and the Royal Navy was not completely forthcoming on their condition during the sale.

However, Stephen Saunders, editor of Jane's Fighting Ships, argued that "there is not something inherently wrong with the class of submarines.

"[21] In 2008, Babcock Canada was awarded the contract to support the Victoria class in Canadian service in the period up to 2023.

The potential value of the contract was over CAD $3.6 billion and required establishing a supply chain in Canada to support and sustain the submarines.

During her sea trials, Windsor suffered minor flooding while submerged, forcing her early entry into the CWP.

[10] On 29 June 2003, following the completion of her CWP, Victoria transferred to the west coast, arriving at Esquimalt, British Columbia on 24 August.

Once the lower hatch was opened, the submarine was hit by a large wave thereby throwing roughly 500 imperial gallons (2,300 L) of sea water into Chicoutimi.

[26] The first ship on the scene was the Irish patrol vessel LÉ Róisín, which suffered damage in the heavy seas and was forced to return to port.

Following the assessment, Chicoutimi was carried to Esquimalt aboard the submersible heavy-lift ship Tern, arriving on 29 April 2009 to undergo a major refit.

In the following year and a half, the submarine took part in several international naval exercises and training periods with other Canadian units.

[12] Victoria performed several sea trials and training exercises before beginning a major refit, called the Extended Docking Work Period (EDWP), on 27 June 2005.

[12] In 2007 Corner Brook participated in the NATO naval exercise "Joint Warrior", marking the first time in fifteen years that a Canadian submarine had sailed in European waters.

[11] On 4 June 2011, Corner Brook while diving off the coast of British Columbia slammed into the seafloor at 5.9 knots (11 km/h) at a depth of 45 metres (148 ft).

[10] Victoria was declared fully operational in March 2012 and participated in the RIMPAC naval exercise that year, sinking ex-USNS Concord with one of her torpedoes.

[38] Chicoutimi and Victoria were taken out of active service in 2016 after hundreds of welds were found to not meet quality standards, affecting the ability of the subs to dive.

The vessel returned to Canada on 21 March 2018 spending 197 days at sea, the longest deployment by a Victoria-class submarine in Canadian service.

[42] Under the Justin Trudeau government's defence policy paper, Strong Secure Engaged (2017), the operational life of each Victoria-class boat was to be extended by one additional "life-cycle" (or by about eight years).

Analysis by the Naval Association of Canada indicated that the lead times, technical challenges and costs involved in submarine replacement would be significant were such a program to be initiated.