HMCS Windsor

Last updated

HMCS Windsor SSK 877.jpg
Windsor underway
History
Naval Ensign of the United Kingdom.svgUnited Kingdom
NameUnicorn
Builder Cammell Laird, Birkenhead
Laid down13 March 1990
Launched16 April 1992
Commissioned25 June 1993
Decommissioned16 October 1994
FateTransferred to Canada 1998
Naval ensign of Canada.svgCanada
NameWindsor
Acquired6 August 2001
Commissioned4 October 2003 [1] [a]
Motto“Silent Pride”
Statusin active service
NotesColours: Gold and Blue
Badge Badge of HMCS Windsor (official).jpg
General characteristics
Class and type Upholder/Victoria-class submarine
Displacement
  • 2,185 long tons (2,220 t) surfaced
  • 2,400 long tons (2,439 t) submerged
Length70.26 m (230 ft 6 in)
Beam7.6 m (24 ft 11 in)
Draught5.5 m (18 ft 1 in)
Propulsion
  • Diesel-electric (37 MW (50,000 hp))
  • 2 Paxman Valenta 16 RPA diesel generators, 4,070 hp (3,030 kW)
  • 2 GEC, 5,000 kW (6,700 hp) motor-generators
Speed
  • 12 knots (22 km/h; 14 mph) surfaced
  • 20 kn (23 mph; 37 km/h)+ submerged
Range10,000 nautical miles (19,000 km) at 12 knots (22 km/h)
Test depth200 m (660 ft)
Complement53 officers and crew
Armament

HMCS Windsor is a long-range hunter-killer (SSK) submarine of the Royal Canadian Navy, the second submarine 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 United Kingdom decided to move to an all-nuclear power fleet.

Contents

Design

As built the Upholder/Victoria class was designed as a replacement for the Oberon class for use as hunter-killer and training subs. The submarines, which have a single-skinned, teardrop-shaped hull, displace 2,220 long tons (2,260 t) surfaced and 2,455 long tons (2,494 t) submerged. [3] [4] They are 230 feet 7 inches (70.3 m) long overall with a beam of 25 feet 0 inches (7.6 m) and a draught of 17 feet 8 inches (5.4 m). [3]

The submarines are powered by a one shaft diesel-electric system. They are equipped with two Paxman Valenta 1600 RPS SZ diesel engines each driving a 1.4- megawatt (1,900  hp ) GEC electric alternator with two 120-cell chloride batteries. [3] [5] The batteries have a 90-hour endurance at 3 knots (5.6 km/h; 3.5 mph). [5] The ship is propelled by a 5,000-kilowatt (6,700 hp) GEC dual armature electric motor turning a seven-blade fixed pitch propeller. [5] They have a 200-long-ton (200 t) diesel capacity. This gives the subs a maximum speed of 12 knots (22 km/h; 14 mph) on the surface and 20 knots (37 km/h; 23 mph) submerged. They have a range of 8,000 nautical miles (15,000 km; 9,200 mi) at 8 knots (15 km/h; 9.2 mph) and 10,000 nautical miles (19,000 km; 12,000 mi) at snorting depth. [3] [6] The class has a reported dive depth of over 650 feet (200 m). [4]

The Upholder/Victoria class are armed with six 21-inch (533 mm) torpedo tubes. In British service, the submarines were equipped with 14 Tigerfish Mk 24 Mod 2 torpedoes and four UGM-84 Sub-Harpoon missiles. [3] They could also be adapted for use as a minelayer. [6] The submarines have Type 1007 radar and Type 2040, Type 2019, Type 2007 and Type 2046 sonar installed. [3] The hull is fitted with elastomeric acoustic tiles to reduce acoustic signature. [4] In British service the vessels had a complement of 7 officers and 40 ratings. [3]

Refits and Canadian alterations

During the refit for Canadian service, the Sub-Harpoon and mine capabilities were removed and the submarines were equipped with the Lockheed Martin Librascope Submarine fire-control system (SFCS) to meet the operational requirements of the Canadian Navy. Components from the fire control system of the Oberon-class submarines were installed. [7] This gave the submarines the ability to fire the Gould Mk 48 Mod 4 torpedo. [4] In 2014, the Government of Canada purchased 12 upgrade kits that will allow the submarines to fire the Mk 48 Mod 7AT torpedoes. [8]

These radar and sonar systems were later upgraded with the installation of the BAE Type 2007 array and the Type 2046 towed array. [3] [4] The Canadian Towed Array Sonar (CANTASS) has been integrated into the towed sonar suite. [4] The Upholder-class submarines were equipped with the CK035 electro-optical search periscope and the CH085 optronic attack periscope, originally supplied by Pilkington Optronics. [4] [5] 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. [4]

Operational history

Royal Navy

The submarine was laid down as HMS Unicorn at Cammell Laird's Birkenhead yard on 13 March 1990. [9] She was launched on 16 April 1992, and commissioned into the Royal Navy on 25 June 1993. [9] She was the last ship built at Cammell Laird until construction began on HMS Queen Elizabeth in June 2010.

After entering service, Unicorn operated in the Mediterranean Sea 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. [9]

Transfer

Looking to discontinue the operation of diesel-electric boats, the British government offered to sell Unicorn and her sister submarines to Canada in 1993. [10] The offer was accepted in 1998. [10] The four boats were leased to Canada 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. [9]

Problems were discovered with the piping welds on all four submarines, which delayed the reactivation of Unicorn and her three sisters. [9] Unicorn was handed over to the Canadian Forces on 6 August 2001 and sailed to Canada, arriving on 19 October. [11] The submarine was commissioned into Maritime Command as HMCS Windsor with the hull number SSK 877 on 4 October 2003. [9]

Royal Canadian Navy

Windsor is the only Canadian submarine deployed in the Atlantic. [12] In April 2002, after departing for the submarine's first training mission, Windsor was forced to return to port after the discovery of a faulty seal in the communications mast. [11] From 27–30 September 2004, Windsor took reporters and photographers from Halifax and Windsor newspapers to document life aboard a submarine. [13] During April 2006, the submarine was involved in the naval exercise Joint Express. [14]

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. [15] During the refit, rust was discovered which will restrict the maximum depth to which the submarine can safely dive. [16] According to reports, due to unexpected problems, the refit suffered delays and cost overruns. These included bad welds in the hull, broken torpedo tubes, a faulty rudder and tiles on the side of the sub that continually fell off. In 2010, the Royal Canadian Navy spent $45 million on repairs to Windsor for which it had budgeted $17 million. The refit began in 2007 and was scheduled to be completed in 2009. The submarine was relaunched on 11 April 2012. [17] [18] After being out of the water for five years, Windsor was lowered back into the water. The submarine was then guided out of the lift area to a nearby dock where the submarine remained for more testing until sea trials. [19]

Shortly afterwards one of the engines was declared unusable, and Windsor was drydocked in March 2014. Work was scheduled to be completed in September at a projected cost of $1.5 million. [12] The work was expanded in June to incorporate other maintenance needs on the submarine as well as a main sonar system upgrade for a total cost of $18 million. [20] On 8 October 2014, Windsor completed her dry-dock maintenance and upgrade cycle and was re-floated. [21]

In Fall 2015, Windsor deployed for large NATO naval exercises Joint Warrior and Trident Venture with Athabaskan, Halifax, Montréal, Goose Bay and Summerside, returning on 17 December. [22] On 15 February 2016, while operating off the US East coast, one of her batteries was found leaking a discharge. The submarine put into Norfolk, Virginia where she awaited specialists from Canada to arrive. After repairs were performed at Norfolk, Windsor returned to Halifax in March 2016. [23] [24]

The submarine deployed in June 2016 to participate in NATO naval exercises off the coast of Norway. However, while in transit, one of the submarine's diesel generators refused to engage. The submarine returned to Halifax for repairs, which were effected and the submarine sailed for Europe a week later. [25] [26] The submarine returned to Halifax on 9 August. [27] In September Windsor was among the Canadian warships deployed to the NATO naval training exercise "Cutlass Fury" off the east coast of North America. [28] Beginning in February 2017, Windsor deployed into the Atlantic Ocean, taking part in a NATO naval exercise and monitoring sea traffic in shipping lanes. The submarine returned to Halifax on 20 June 2018. [29]

In September 2023, the submarine suffered a flooding incident in which three sailors were injured. Although scheduled to participate in a 14-day multi-national exercise, Windsor was compelled to return to Halifax where repairs were expected to take four weeks. [30]

Related Research Articles

<i>Upholder/Victoria</i>-class submarine Class of diesel-electric attack submarine

The Upholder/Victoria-class submarines, also known as the Type 2400, are a class of diesel-electric submarines built in the United Kingdom in the 1980s to supplement the nuclear submarines in the Submarine Service of the British Royal Navy.

HMCS <i>Victoria</i> (SSK 876) Royal Canadian Navy hunter-killer submarine

HMCS Victoria is a long-range hunter-killer (SSK) submarine of the Royal Canadian Navy, the lead ship of her class. She is named after the city of Victoria, British Columbia. She was purchased from the Royal Navy, and is the former HMS Unseen (S41). The class was also renamed from the Upholder class.

HMCS <i>Toronto</i> (FFH 333) Royal Canadian Navy frigate

HMCS Toronto is a Halifax-class frigate that has served in the Canadian Forces since 1993. Toronto is the fourth ship in her class which is the name for the Canadian Patrol Frigate Project. She is the second RCN ship to be named for Canada's largest city. When not on operations, she is assigned to Maritime Forces Atlantic (MARLANT) and is based at CFB Halifax. Toronto serves on MARLANT missions protecting Canada's sovereignty in the Atlantic Ocean and enforcing Canadian laws in its territorial sea and exclusive economic zone.

HMCS <i>Onondaga</i>

HMCS Onondaga (S73) is an Oberon-class submarine that served in the Royal Canadian Navy and later the Canadian Forces. Built in the mid-1960s, Onondaga operated primarily with the Maritime Forces Atlantic until her decommissioning in 2000 as the last Canadian Oberon.

HMCS <i>Okanagan</i>

HMCS Okanagan (S74) was an Oberon-class submarine that served in the Canadian Forces (CF). She entered service in 1968 and spent the majority of her career on the east coast. The ship was paid off in 1998 and sold for scrap in 2011.

HMCS <i>Ojibwa</i>

HMCS Ojibwa is an Oberon-class submarine that served in the Royal Canadian Navy (RCN) and later the Canadian Forces Maritime Command (MARCOM). Originally intended for service with the British Royal Navy as HMS Onyx, the submarine was transferred to Canadian ownership before completion, and entered RCN service in 1965. Ojibwa operated primarily with Maritime Forces Atlantic until her decommissioning in 1998. In 2010, Ojibwa was laid up at CFB Halifax awaiting disposal, with the Elgin Military Museum planning to preserve her as a museum vessel. The submarine was towed to Port Burwell, Ontario in 2012, and was opened to the public in 2013. She is now the new focal point of a planned Museum of Naval History to be built alongside.

HMCS <i>Chicoutimi</i> (SSK 879) Royal Canadian Navy hunter-killer submarine

HMCS Chicoutimi is a Victoria-class long-range hunter-killer (SSK) submarine of the Royal Canadian Navy, originally built and operated by the Royal Navy as HMS Upholder. Shortly after being handed over by the United Kingdom to Canada she was involved in a partial flooding incident which resulted in a fire at sea. The incident sparked a fierce debate over the value of the purchase of this group of second-hand vessels, as well as the handover inspection process. The subsequent investigation "determined the fire was caused by human, technical and operational factors, [and] the board cleared the commanding officer and crew of any blame." The submarine was repaired and entered Canadian service in 2015.

HMCS <i>Halifax</i> (FFH 330) Royal Canadian Navy frigate

HMCS Halifax is a Halifax-class frigate that has served in the Royal Canadian Navy and Canadian Forces since 1992. Halifax is the lead ship in her class which is the name for the Canadian Patrol Frigate Project. She is the second vessel to carry the designation HMCS Halifax. She carries the hull classification symbol FFH 330.

HMCS <i>Vancouver</i> (FFH 331) Royal Canadian Navy frigate

HMCS Vancouver is a Halifax-class frigate, of the Royal Canadian Navy launched on 8 July 1989, as the second vessel of her class. She is based at CFB Esquimalt on the west coast of Canada, and is the third vessel to be named after Vancouver, British Columbia.

HMCS <i>Montréal</i> (FFH 336) Royal Canadian Navy frigate

HMCS Montréal is a Halifax-class frigate that has served in the Canadian Forces since 1993. Montréal is the seventh ship in her class which is based on the Canadian Patrol Frigate Project. She is the second vessel to carry the designation HMCS Montreal. She is assigned to Maritime Forces Atlantic (MARLANT) and is homeported at CFB Halifax. Montréal serves on MARLANT missions protecting Canada's sovereignty in the Atlantic and Arctic Oceans and enforcing Canadian laws in its territorial sea and Exclusive Economic Zone. The ship has also been deployed on missions throughout the Atlantic and to the Indian Ocean; specifically the Persian Gulf and Arabian Sea on anti-terrorism operations. The vessel has also participated in several NATO missions, patrolling the Atlantic Ocean as part of Standing Naval Force Atlantic (STANAVFORLANT) and its successor Standing NATO Response Force Maritime Group 1 (SNMG1). The vessel is designated as a Bilingual Language Unit in the Royal Canadian Navy.

HMCS <i>Fredericton</i> (FFH 337) Royal Canadian Navy frigate

HMCS Fredericton is a Halifax-class frigate that has served in the Canadian Forces since 1994. Fredericton is the eighth ship in her class which is based on the Canadian Patrol Frigate Project. She is the second vessel to carry the name. Fredericton serves on MARLANT missions protecting Canada's sovereignty in the Atlantic Ocean and enforcing Canadian laws in its territorial sea and Exclusive Economic Zone. Fredericton has also been deployed on missions throughout the Atlantic and to the Indian Ocean; specifically the Persian Gulf and Arabian Sea on anti-terrorism operations. Fredericton has also participated in several NATO missions, patrolling the Atlantic Ocean as part of Standing Naval Force Atlantic (STANAVFORLANT) and its successor Standing NATO Response Force Maritime Group 1 (SNMG1). The frigate is assigned to Maritime Forces Atlantic (MARLANT) and is homeported at CFB Halifax.

HMCS <i>Charlottetown</i> (FFH 339) Royal Canadian Navy frigate

HMCS Charlottetown is a Halifax-class frigate that has served in the Royal Canadian Navy since 1995. Charlottetown is the tenth ship in her class which is based on the Canadian Patrol Frigate Project. She is the third vessel to carry the designation HMCS Charlottetown. Charlottetown, assigned to Maritime Forces Atlantic (MARLANT) and homeported at CFB Halifax, serves on missions protecting Canada's sovereignty in the Atlantic Ocean and enforcing Canadian laws in its territorial sea and exclusive economic zone. Charlottetown has also participated in several NATO missions, patrolling the Atlantic Ocean as part of Standing Naval Force Atlantic (STANAVFORLANT) and its successors Standing NATO Maritime Group 1 and 2. Charlottetown has also been deployed on missions throughout the Atlantic and to the Indian Ocean, specifically the Persian Gulf and Arabian Sea on anti-terrorism operations.

HMCS <i>Regina</i> (FFH 334) Royal Canadian Navy frigate

HMCS Regina is a Halifax-class frigate that has served in the Canadian Forces and Royal Canadian Navy since 1993. Regina is the fifth vessel in her class which is the name for the Canadian Patrol Frigate Project. She is the second vessel to carry the designation HMCS Regina. She is assigned to Maritime Forces Pacific (MARPAC) and is homeported at CFB Esquimalt.

HMCS <i>St. Johns</i> Royal Canadian Navy frigate

HMCS St. John's is a Halifax-class frigate that has served in the Canadian Forces and the Royal Canadian Navy since her commissioning in 1996. She is the eleventh of twelve ships in her class which is based on the Canadian Patrol Frigate Project. St. John's is named after the city of St. John's, Newfoundland and Labrador, a port city associated with Canadian naval history and heritage, and is the first ship in the Royal Canadian Navy to bear the name.

HMCS <i>Ville de Québec</i> (FFH 332) Royal Canadian Navy frigate

HMCS Ville de Québec is a Halifax-class frigate that has served in the Canadian Forces and Royal Canadian Navy since 1993. Ville de Québec is the third vessel in her class which is the name for the Canadian Patrol Frigate Project. The frigate is the second Royal Canadian Navy ship to be named Ville de Québec and is Canada's only fully bilingual warship. She is assigned to Maritime Forces Atlantic (MARLANT) and is homeported at CFB Halifax. The vessel serves on MARLANT missions protecting Canada's sovereignty in the Atlantic Ocean and enforcing Canadian laws in its territorial sea and exclusive economic zone.

HMCS <i>Winnipeg</i> (FFH 338) Royal Canadian Navy frigate

HMCS Winnipeg is a Halifax-class frigate that has served in the Royal Canadian Navy since 1996. Winnipeg is the ninth ship in her class, whose design emerged from the Canadian Patrol Frigate Project. She is the second Canadian warship to carry the name HMCS Winnipeg. Winnipeg serves on Canadian Forces MARPAC missions protecting Canada's sovereignty in the Pacific Ocean and the Arctic Ocean and in enforcing Canadian laws on its territorial oceans and Exclusive Economic Zone. The vessel has been deployed on missions throughout the Pacific, and also to the Indian Ocean; specifically on anti-terrorism operations in the Persian Gulf and the Arabian Sea, and counter-piracy operations off the coast of Somalia. The ship is assigned to the Maritime Forces Pacific (MARPAC), and she has her home port at the Canadian Forces Maritime Base at Esquimalt.

HMCS <i>Algonquin</i> (DDG 283) Destroyer of the Royal Canadian Navy

HMCS Algonquin was an Iroquois-class destroyer that served in the Royal Canadian Navy (RCN) from 1973 to 2015.

HMCS <i>Corner Brook</i> Royal Canadian Navy hunter-killer submarine

HMCS Corner Brook is a long-range hunter-killer submarine (SSK) of the Royal Canadian Navy. She is the former Royal Navy Upholder-class submarine HMS Ursula (S42), purchased from the British at the end of the Cold War. She is the third boat of the Victoria class and is named after the city of Corner Brook, Newfoundland. The submarine was launched in 1989 and entered service with the Royal Navy in 1992. The Royal Navy laid Ursula up in 1994. In 1998, Canada acquired the submarine from the United Kingdom. The vessel entered service with the Canadian Armed Forces in 2003. Renamed Corner Brook, the submarine took part in several military exercises both internationally, such as NATO exercises and domestic, such as Operation Nanook. In June 2011, the submarine ran aground in Nootka Sound, damaging the vessel's bow. The submarine was sent for refit in 2014 to complete the repairs.

HMCS <i>Annapolis</i> (DDH 265) Destroyer of the Royal Canadian Navy

HMCS Annapolis was an Annapolis-class destroyer that served in the Royal Canadian Navy and later, the Canadian Forces. She was the second Canadian naval unit to carry this name. Named for the Annapolis River that flows through Nova Scotia, the ship entered service in 1964, the last of the St. Laurent-class design. Serving through the Cold War, Annapolis was decommissioned in 1998 before going through a protracted legal battle for use as an artificial reef. She was finally scuttled as such in 2015 off the coast of British Columbia.

HMCS <i>Saskatchewan</i> (DDE 262) Mackenzie-class destroyer of the Royal Canadian Navy

HMCS Saskatchewan was a Mackenzie-class destroyer that served in the Royal Canadian Navy (RCN) and later the Canadian Forces. She was the second Canadian naval unit to bear the name HMCS Saskatchewan. The ship was named for the Saskatchewan River which runs from Saskatchewan to Manitoba in Canada.

References

Notes

  1. The Canadian Department of National Defence has a different commissioning date for the submarine, on 29 September 2001, according to the official lineage. [2]

Citations

  1. "His Majesty's Canadian Submarine Windsor (SSK 877)". Government of Canada. 13 October 2022. Retrieved 16 November 2024.
  2. "Volume 2: Volume 2, Part 1: Extant Commissioned Ships". Official Lineages. National Defence and the Canadian Forces. 7 July 2006. Archived from the original on 6 October 2014. Retrieved 1 October 2014.
  3. 1 2 3 4 5 6 7 8 Gardiner and Chumbley, p. 532
  4. 1 2 3 4 5 6 7 8 Saunders, p. 88
  5. 1 2 3 4 Perkins, p. 196
  6. 1 2 Cocker, p. 123
  7. Perkins, p. 166
  8. Pugliese, David (26 September 2014). "Canadian government to spend $41 million for torpedo upgrade kits for submarines". Ottawa Citizen. Archived from the original on 28 February 2018. Retrieved 28 February 2018.
  9. 1 2 3 4 5 6 Wertheim, pp. 77–78
  10. 1 2 Ferguson, p. 152
  11. 1 2 Macpherson and Barrie, p. 298
  12. 1 2 "Submarine HMCS Windsor shore bound after engine failure". CBC News. 5 February 2014. Archived from the original on 23 February 2014. Retrieved 6 February 2014.
  13. "Image Gallery". Royal Canadian Navy . Canadian Forces. Archived from the original on 13 June 2011.
  14. "Ex Joint Express". Royal Canadian Navy . Canadian Forces. Archived from the original on 13 June 2011.
  15. "Submarine refit wildly over budget". CBC News. 24 February 2011. Archived from the original on 11 April 2012. Retrieved 11 April 2012.
  16. Tutton, Michael (31 July 2011). "Rust will restrict Canadian submarine's diving range". Toronto Star . Torstar. Archived from the original on 26 March 2012. Retrieved 11 April 2012.
  17. Ware, Beverley (10 April 2012). "Sub in refit to get wet for first time in 5 years". The Chronicle Herald . Archived from the original on 1 February 2018. Retrieved 10 April 2012.
  18. "Troubled sub hits water after lengthy refit". CBC News . 11 April 2012. Archived from the original on 11 April 2012. Retrieved 11 April 2012.
  19. Fairclough, Ian (11 April 2012). "HMCS Windsor lands safely in Halifax Harbour". The Chronicle Herald . Archived from the original on 14 April 2012. Retrieved 20 April 2012.
  20. Pugliese, David (11 June 2014). "HMCS Windsor gets $18 million overhaul – new generator, sonar upgrade and more maintenance". Ottawa Citizen. Archived from the original on 6 October 2014. Retrieved 1 October 2014.
  21. Pugliese, David (10 October 2014). "HMCS Windsor to begin equipment tests and trials in harbour and at sea". Ottawa Citizen. Archived from the original on 16 October 2014. Retrieved 12 October 2014.
  22. "HMCS Windsor returning to Halifax port after NATO exercises". CBC News. 16 December 2015. Archived from the original on 19 December 2015. Retrieved 17 December 2015.
  23. Ward, Rachel (4 March 2016). "HMCS Windsor submarine back in Halifax after battery malfunction". CBC News. Archived from the original on 5 March 2016. Retrieved 5 March 2016.
  24. Ward, Rachel (19 February 2016). "HMCS Windsor battery malfunction delays submarine's return to Halifax". CBC News. Archived from the original on 5 March 2016. Retrieved 5 March 2016.
  25. Ruskin, Brett (5 June 2016). "HMCS Windsor returning to Halifax to repair defective supercharger". CBC News. Archived from the original on 6 June 2016. Retrieved 7 June 2016.
  26. Campion-Smith, Bruce (12 June 2016). "HMCS Windsor back at sea after engine woes". Toronto Star. Archived from the original on 13 June 2016. Retrieved 13 June 2016.
  27. "HMCS Windsor crew welcomed home at Halifax waterfront". CTV News. 9 August 2016. Archived from the original on 11 August 2016. Retrieved 11 August 2016.
  28. "NATO warships converge on Halifax for military exercises". CTV News. 10 September 2016. Archived from the original on 11 September 2016. Retrieved 11 September 2016.
  29. Thomson, Aly (20 June 2018). "Navy submarine HMCS Windsor returns to Halifax after five-month deployment". CTV News. The Canadian Press. Archived from the original on 20 June 2018. Retrieved 20 June 2018.
  30. Dicks, Bill (20 September 2023). "HMCS Windsor repairs expected to take about four weeks; injured crew returned to duty". CTV News Atlantic. Retrieved 29 September 2023.

Sources