The J class was designed by the Royal Navy in response to reported German submarines with surface speeds over 18 knots (33 km/h; 21 mph).[1] The submarines had a displacement of 1,210 tons surfaced, but J7 had a lighter submerged displacement than her sister boats, at 1,760 tons.[1] Each submarine was 275 feet (84 m) in length overall, with a beam of 22 feet (6.7 m), and a draught of 14 feet (4.3 m).[1] The propulsion system was built around three propeller shafts; the J-class were the only triple-screwed submarines ever built by the British.[1] Propulsion came from three 12-cylinder diesel motors when on the surface, and electric motors when submerged.[1] Top speed was 19 knots (35 km/h; 22 mph) on the surface (the fastest submarines in the world at the time of construction), and 9.5 knots (17.6 km/h; 10.9 mph) underwater.[1] Range was 4,000 nautical miles (7,400 km; 4,600 mi) at 12 knots (22 km/h; 14 mph).[1]
Armament consisted of six 18 inch (450 mm) torpedo tubes (four forward, one on each beam), plus a 4-inch deck gun.[1] Originally, the gun was mounted on a breastwork fitted forward of the conning tower, but the breastwork was later extended to the bow and merged into the hull for streamlining, and the gun was relocated to a platform fitted to the front of the conning tower.[1] The conning tower on J7 was sited 60 feet (18 m) further back than her sister boats, as the control room was located behind the machinery spaces.[1][2] 44 personnel were aboard.[1]
After the war, the British Admiralty decided that the best way to protect the Pacific region was with a force of submarines and cruisers.[1] To this end, they offered the six surviving submarines of the J-class to the Royal Australian Navy as gifts.[1]J1 and her sisters were commissioned into the RAN in April 1919, and sailed for Australia on 9 April, in the company of the cruisers Sydney and Brisbane, and the tender Platypus.[1] The flotilla reached Thursday Island on 29 June, and Sydney on 10 July.[1] Because of the submarines' condition after the long voyage, they were immediately taken out of service for refits.[1]
Wreck of HMAS J7 at the Sandringham Yacht Club marina
By the time J7 was returned to service in June 1922, the cost of maintaining the boats and deteriorating economic conditions saw the six submarines decommissioned and marked for disposal.[1]
Fateedit
J7 was paid off on 12 July 1922,[citation needed] and was sold on 26 February 1924[citation needed]. The hulk was scuttled in 1930, for use as a breakwater at the Sandringham Yacht Club in Port Phillip.[4] Some years later a stone marina was constructed around the wreck, which was left in situ and visible, being too expensive to remove, where it continues to deteriorate.[4]
^Tall, J.J; Paul Kemp (1996). HM Submarines in Camera An Illustrated History of British Submarines. Sutton Publishing. p. 54. ISBN0-7509-0875-0.
^"HMAS J7". Royal Australian Navy. Retrieved 13 March 2011.
^ abCallanan, Tim (25 September 2021). "As the spotlight falls on Australia's new submarines, this one is ageing quietly at a Melbourne marina". ABC News. Retrieved 26 September 2021.
Referencesedit
Bastock, John (1975). Australia's Ships of War. Cremorne, NSW: Angus and Robertson. ISBN0207129274. OCLC 2525523.
External linksedit
Map of Sandringham yacht club marina 20 July 2008 at the Wayback Machine
later, hmas, class, submarine, operated, royal, navy, royal, australian, navy, hmas, j7history, united, kingdom, name, builderhm, dockyard, devonport, launched12, february, 1917, fatetransferred, australia, march, 1919, australia, namehmas, acquired25, march, . HMS J7 later HMAS J7 was a J class submarine operated by the Royal Navy and the Royal Australian Navy HMAS J7History United Kingdom NameHMS J7 BuilderHM Dockyard Devonport Launched12 February 1917 FateTransferred to Australia 25 March 1919 Australia NameHMAS J7 Acquired25 March 1919 Decommissioned12 July 1922 FateSunk 4 June 1926 NotesStill extant as breakwater as of 2021 General characteristics Class and typeBritish J class submarine Displacement1 210 long tons 1 230 t surfaced 1 760 long tons 1 790 t submerged Length275 ft 84 m Beam22 ft 6 7 m Draught14 ft 4 3 m PropulsionThree shafts Surfaced three 12 cylinder diesel engines Submerged battery driven electric motors Speed19 kn 35 km h 22 mph surfaced 9 5 kn 17 6 km h 10 9 mph submerged Range4 000 nmi 7 400 km 4 600 mi at 12 kn 22 km h 14 mph Test depth300 ft 91 m max citation needed Complement44 personnel Armamentsix 18 inch 450 mm torpedo tubes four bow two beam one 4 in 102 mm gun Contents 1 Design and construction 2 Operational history 3 Fate 4 Citations 5 References 6 External linksDesign and construction editMain article J class submarine The J class was designed by the Royal Navy in response to reported German submarines with surface speeds over 18 knots 33 km h 21 mph 1 The submarines had a displacement of 1 210 tons surfaced but J7 had a lighter submerged displacement than her sister boats at 1 760 tons 1 Each submarine was 275 feet 84 m in length overall with a beam of 22 feet 6 7 m and a draught of 14 feet 4 3 m 1 The propulsion system was built around three propeller shafts the J class were the only triple screwed submarines ever built by the British 1 Propulsion came from three 12 cylinder diesel motors when on the surface and electric motors when submerged 1 Top speed was 19 knots 35 km h 22 mph on the surface the fastest submarines in the world at the time of construction and 9 5 knots 17 6 km h 10 9 mph underwater 1 Range was 4 000 nautical miles 7 400 km 4 600 mi at 12 knots 22 km h 14 mph 1 Armament consisted of six 18 inch 450 mm torpedo tubes four forward one on each beam plus a 4 inch deck gun 1 Originally the gun was mounted on a breastwork fitted forward of the conning tower but the breastwork was later extended to the bow and merged into the hull for streamlining and the gun was relocated to a platform fitted to the front of the conning tower 1 The conning tower on J7 was sited 60 feet 18 m further back than her sister boats as the control room was located behind the machinery spaces 1 2 44 personnel were aboard 1 J7 was built by HM Dockyard Devonport in Plymouth and launched on 12 February 1917 3 Operational history editAfter the war the British Admiralty decided that the best way to protect the Pacific region was with a force of submarines and cruisers 1 To this end they offered the six surviving submarines of the J class to the Royal Australian Navy as gifts 1 J1 and her sisters were commissioned into the RAN in April 1919 and sailed for Australia on 9 April in the company of the cruisers Sydney and Brisbane and the tender Platypus 1 The flotilla reached Thursday Island on 29 June and Sydney on 10 July 1 Because of the submarines condition after the long voyage they were immediately taken out of service for refits 1 nbsp Wreck of HMAS J7 at the Sandringham Yacht Club marina By the time J7 was returned to service in June 1922 the cost of maintaining the boats and deteriorating economic conditions saw the six submarines decommissioned and marked for disposal 1 Fate editJ7 was paid off on 12 July 1922 citation needed and was sold on 26 February 1924 citation needed The hulk was scuttled in 1930 for use as a breakwater at the Sandringham Yacht Club in Port Phillip 4 Some years later a stone marina was constructed around the wreck which was left in situ and visible being too expensive to remove where it continues to deteriorate 4 Citations edit a b c d e f g h i j k l m n o p q Bastock Australia s Ships of War p 86 Tall J J Paul Kemp 1996 HM Submarines in Camera An Illustrated History of British Submarines Sutton Publishing p 54 ISBN 0 7509 0875 0 HMAS J7 Royal Australian Navy Retrieved 13 March 2011 a b Callanan Tim 25 September 2021 As the spotlight falls on Australia s new submarines this one is ageing quietly at a Melbourne marina ABC News Retrieved 26 September 2021 References editBastock John 1975 Australia s Ships of War Cremorne NSW Angus and Robertson ISBN 0207129274 OCLC 2525523 External links editMap of Sandringham yacht club marina Archived 20 July 2008 at the Wayback Machine 37 56 36 S 144 59 41 E 37 943381 S 144 99471 E 37 943381 144 99471 Retrieved from https en wikipedia org w index php title HMS J7 amp oldid 1196035582, wikipedia, wiki, book, books, library,
