Military Wiki
HMCS Windsor
HMCS Windsor (SSK 877)
Career (United Kingdom)
Name: HMS Unicorn
Builder: Cammell Laird, Birkenhead
Laid down: 13 March 1990
Launched: 16 April 1992
Commissioned: 25 June 1993
Decommissioned: 16 October 1994
Fate: Transferred to Canada
Career (Canada)
Name: HMCS Windsor
Acquired: 6 August 2001
Commissioned: 29 September 2001[1]
Status: in active service, as of 2022 In drydock undergoing refit
Notes: Colours: Gold and Blue
Badge: 200px
General characteristics
Class & type: Upholder/Victoria-class submarine
Displacement: 2,185 long tons (2,220 t) surfaced
2,400 long tons (2,439 t) submerged
Length: 70.26 m (230 ft 6 in)
Beam: 7.6 m (24 ft 11 in)
Draught: 5.5 m (18 ft 1 in)
Propulsion: Diesel-electric (37 MW)
2 Paxman Valenta 16 RPA diesel generators, 4,070 hp (3,035 kW)
2 GEC, 5,000 kW motor-generators
Speed: 12 knots (14 mph; 22 km/h) surfaced
20 kn (23 mph; 37 km/h)+ submerged
Range: 10,000 nautical miles (19,000 km) at 12 knots (22 km/h)
Test depth: 200 m (660 ft)
Complement: 53 officers and crew
Armament: • 6 × 21 in (530 mm) torpedo tubes
• 18 × Mark 48 torpedoes

HMCS Windsor (SSK 877) is a long-range hunter-killer (SSK) submarine of the Royal Canadian Navy, the second ship of the Victoria class. She is named after the city of Windsor, Ontario. Built for the Royal Navy as the Upholder class submarine HMS Unicorn (pennant number S43) she was purchased by Canada when the UK decided to move to an all-nuclear power fleet.


HMCS Windsor's displacement is approximately 2,200 tons surfaced and 2,400 tons submerged. Covered in anechoic tiles to reduce her detection by active sonar, the submarine is 70.3 metres long, 7.6 metres across the beam and has a deep diving depth in excess of 200 metres. The main hull is constructed of high tensile steel sections stiffened by circular internal frames. Equipment located outside the main hull is covered by the casing, which also gives the crew a safe walkway when the submarine is surfaced. The fin, which helps support the masts, serves as a kind of keel and provides a raised conning position.

HMCS Windsor has six torpedo tubes and can carry up to eighteen Mark 48 Mod 4 heavyweight torpedoes for use against surface and sub-surface targets.

HMCS Windsor's sonar sets allow her to locate and track ships and other submarines “passively”, that is without transmitting on active sonar and thus giving away her location. She is fitted with radar for general navigation, attack and search periscopes (incorporating video recording and thermal imaging), and an electronic support measures suite. The ship has two diesel generators, each capable of producing up to 1,410 kilowatts, and one main motor. The generators are used to charge two main batteries, each consisting of 240 battery cells. These batteries are used to power the submarine, which can reach a submerged speed of up to 20 knots (37 km/h).


The submarine was laid down as HMS Unicorn at Cammell Laird's Birkenhead yard on 13 March 1990.[2] She was launched on 16 April 1992, and commissioned into the Royal Navy on 25 June 1993.[2] She was the last ship built at Cammell Laird until construction began on HMS Queen Elizabeth in June 2010.

Operational history

Royal Navy

Unicorn operated in the Mediterranean and east of Suez, the Gulf of Oman and Indian Ocean and in the Persian Gulf. She returned to Devonport and was decommissioned on 16 October 1994.[2]


Looking to discontinue the operation of diesel-electric boats, the British government offered to sell Unicorn and her sister submarines to Canada in 1993.[3] The offer was accepted in 1998.[3] The four boats were leased to the Canadians for US$427 million (plus US$98 million for upgrades and alteration to Canadian standards), with the lease to run for eight years; after this, the submarines would be sold for £1.[2]

Problems were discovered with the piping welds on all four submarines, which delayed the reactivation of Unicorn and her three sisters.[2] Unicorn was handed over to the Royal Canadian Navy on 6 August 2001, and was commissioned as HMCS Windsor on 4 October 2003.[2]

Royal Canadian Navy

Question book-new.svg

The factual accuracy of this article may be compromised due to out-of-date information

From September 27 to 30 2004, Windsor took reporters and photographers from Halifax and Windsor newspapers to document life aboard a submarine.[4]

During April 2006, the submarine was involved in Exercise Joint Express.[5]

In 2007 the submarine entered Halifax for refit. Originally scheduled for completion in two years, the refit was still not complete as of early 2011.[6] During the refit, rust was discovered which will restrict the maximum depth to which the submarine can safely dive.[7]

According to the CBC, a number of unexpected problems have led to delays and cost overruns.

The cost to refit one of Canada's trouble-plagued submarines is skyrocketing, according to documents obtained under an access to information request by CBC News.
In the year 2010 alone, the RCN spent $45 million on repairs to HMCS Windsor. It had budgeted to spend just $17 million, the documents show.
It appears that every system on the British-built submarine has major problems, according to the documents, including bad welds in the hull, broken torpedo tubes, a faulty rudder and tiles on the side of the sub that continually fall off.
The refit of the Windsor is also taking much longer to complete than anticipated, the documents show. The refit started in 2007 and was scheduled to be completed in 2009. However, the documents indicate the Windsor won't be fully operational until almost 2013. She was relaunched on April 11, 2012.[8][9]
Because the submarine has been in drydock in Halifax for so long, the navy has had to spend thousands of dollars just trying to keep the pigeons from roosting in the vessel.[10]

On April 11, 2012, after being out of the water for 5 years, HMCS Windsor was lowered back into the water. HMCS Windsor was then guided out of the lift area to a nearby dock where it is to remain for more testing until its three to five month sea trials, which are scheduled to begin at the end of April 2012.[11]


  1. National Defence and the Canadian Forces (2012) Official Lineages, Volume 2: Ships. Retrieved from
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Wertheim, Eric, ed (2007). The Naval Institute Guide to Combat Fleets of the World: Their Ships, Aircraft, and Systems (15th ed.). Annapolis, MD: Naval Institute Press. pp. 77–78. ISBN 978-1-59114-955-2. OCLC 140283156. 
  3. 3.0 3.1 Ferguson, Julie H. (2000). Deeply Canadian: New Submarines for a New Millennium. Beacon Publishing. p. 152. ISBN 0-9689857-0-X. 
  4. "Image Gallery". Royal Canadian Navy. Canadian Forces. Archived from the original on 2011-06-13. 
  5. "Ex Joint Express". Royal Canadian Navy. Canadian Forces. Archived from the original on 2011-06-13. 
  6. "Submarine refit wildly over budget". CBC News. February 24, 2011. Retrieved 2012-04-11. 
  7. Tutton, Michael (July 31, 2011). "Rust will restrict Canadian submarine's diving range". Toronto Star. Torstar. Retrieved 2012-04-11. 
  8. Ware, Beverley (April 10, 2012). "Sub in refit to get wet for first time in 5 years". The Chronicle Herald. Retrieved 2012-04-10. 
  9. "Troubled sub hits water after lengthy refit". CBC News. April 11, 2012. Retrieved 2012-04-11. 
  10. "Submarine refit wildly over budget". CBC News. February 23, 2011. Retrieved 2012-04-11. 
  11. Fairclough, Ian (April 11, 2012). "HMCS Windsor lands safely in Halifax Harbour". The Chronicle Herald. The Chronicle Herald. Retrieved 2012-04-20. 

External links

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