Upholder/Victoria-class submarine

In the late 1970s the United Kingdom Ministry of Defence (MoD) proposed a diesel-electric submarine design to replace the Oberon class. The new submarine class was intended to provide a more cost-effective alternative for training and in coastal defence. The announcement for the new design took place in September 1979. Five designs were put forward, with the MoD selecting the 1,960-ton design. However, the need for export potential upped the displacement limit to 2,400 tons to allow for flexibility in construction if the need for alternative machinery and systems arose. The submarines are long overall with a beam of and a draught of . The submarines had a complement between 44 and 47 with the Royal Navy. The batteries have a 90-hour endurance at . This gave the submarines the ability to fire the Gould Mk 48 Mod 4 torpedo. Sensors and countermeasures As built, the Upholder class was equipped with the Kelvin Hughes Type 1007 I-band radar for navigational purposes. The submarines were fitted with the Type 2040 Thompson Sintra ARGONAUTE hull mounted sonar, installed in the bow and Type 2026 GEC Avionics passive towed array. The submarines had the Type 2019 Thompson Sintra PARIS passive sonar for active and intercept purposes. They also had the Type 2041 passive ranging sonar and the Type 2004 expendable bathythermograph. The class was fitted with Type 2008 underwater telephone. The Type 2040 sonar was intended to be upgraded to Type 2075; however, that upgrade was cancelled in 1991. These systems were later upgraded with the installation of the BAE Type 2007 array and the Type 2046 towed array. The Canadian Towed Array Sonar (CANTASS) has been integrated into the towed sonar suite. The Upholder-class submarines were equipped with the CK035 electro-optical search periscope and the CH085 optronic attack periscope, originally supplied by Pilkington Optronics. After the Canadian refit, the submarines were equipped with Canadian communication equipment and electronic support measures (ESM). This included two SSE decoy launchers and the AR 900 ESM. ==Construction and Royal Navy service==

The plan initially called for twelve submarines to be built. However, formal approval was given in 1981 for the construction of only nine. Unicorn was paid off on 16 October 1994 and laid up. ==Search for a buyer==

Failed sale to Pakistan In 1992, the United Kingdom learned that Pakistan had been in negotiations with France over the acquisition of submarines. The Sharif administration gave permission to the Pakistan Navy to acquire either diesel-electric powered or air-independent powered submarines. 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 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. Sale to Canada Following the cancellation of the Canadian nuclear-powered submarine program, the Canadian navy sought to acquire conventionally-powered submarines again. The Canadian National Defence White Paper of 1994 stated the intent to explore the purchase of the Upholder class from the UK. 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. In the meantime, the subs were offered to Portugal and Chile. In 1996, another attempt to purchase the subs by Canada was stopped soon after starting. In the meantime, the UK spent millions maintaining the submarines. On 3 July 1998, the deal was ratified and two contracts were signed simultaneously. The first was an eight-year interest-free lease-to-purchase agreement for the four submarines, five training simulators and assorted training and data packages. 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. 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." 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. Every six to nine years each Victoria-class boat undergoes an extended docking work period (EDWP) involving comprehensive maintenance, repair, overhaul or upgrading of over 200 systems including sonar upgrades, mast upgrades and combat system upgrades. Trainers Victoria-class submarines use eight Submarine Command Team Trainers built for the Royal Navy. These were moved from the UK to Canada by CAE, Computing Devices Canada, General Dynamics Canada and Irving Shipbuilding. These devices are land-based systems using simulators and other training devices. Victoria-class submarines also use a Canadian Submarine Escape Trainer, attached to a real submarine escape hatch to simulate escape procedures. ==Canadian service==

Upon acquiring the subs, Maritime Command suggested that the subs would be operational by 2000. This included an 18-month systems check. Each sub would undergo a six-month Canadian Work Period (CWP). During the CWP, Canadian communications and fire control systems were installed. The first ship on the scene was the Irish patrol vessel , which suffered damage in the heavy seas and was forced to return to port. The British frigate arrived the following day to provide aid. Rescue efforts had been hampered by the poor weather. The three seriously injured crewmen were evacuated by Montroses helicopter and flown directly to Sligo, Ireland. One sailor died of his injuries shortly after arrival. Chicoutimi was taken in tow on 7 October and arrived back at Faslane on 9 October. Chicoutimi was transported to Halifax aboard the submersible heavy-lift vessel Eide Transporter, arriving on 1 February 2005. The commissioning of the submarine was delayed until the assessment of the damage could take place. 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. The submarine surfaced and made port without requiring aid. Repairs and a major refit kept the sub out of operational service until 2018. Victoria emerged from the EDWP at the end of 2011. During the cruise, Windsor was deployed to track five submarines from another nation that had entered the North Atlantic. Canada announced plans for a major life extension for the class on 7 April 2015, possibly to start in 2020. The estimated cost for the program would be between $1.5 and $2 billion CAN. , October 2017 On 3 September 2015, Chicoutimi was commissioned into the Royal Canadian Navy at Esquimalt. However, the sub was restricted to shallow-water diving. In October 2015, Chicoutimi was among the Canadian vessels sent to participate in a joint exercise with the United States Navy. 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. They were docked at Esquimalt for several months. Chicoutimi was repaired first, followed by Victoria. Victoria was used for training purposes until repairs were effected. In September 2017, Canada deployed Chicoutimi on patrol in Asian waters, the first such deployment by a Victoria-class submarine. During the deployment, Chicoutimi marked the first visit to Japan by a Canadian submarine since 1968. 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. Life extension and replacement 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). This was designed to permit the operation of the fleet into about the early to mid-2030s. As of 2020 no decision had been taken on the actual replacement of Canada's submarines which were then already thirty years old. 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. According to John Ivison, Royal Canadian Navy personnel assessed six submarines that could be a potential replacement. They consist of the conventional , the Type 212CD, the , the KSS-III class, the Isaac Peral class and the . On 10 July 2024, the Government of Canada announced the Canadian Patrol Submarine Project (CPSP). Up to 12 conventionally powered submarines are to be acquired for the RCN. An RFI was issued by Public Services and Procurement Canada (PSPC) in September 2024. On 21 November, it was reported that the Taigei class was no longer being considered. In August 2025, the government narrowed the choice down to the Type 212CD and the KSS-III. David Pugliese in the Ottawa Citizen reported that former navy officers estimated the program costs would be around $100 billion with the first new submarines estimated to be ready by 2037. ==Boats in class==