26-671: (Redirected from U-class ) U class or Class U may refer to: British U-class submarine , submarines built just before and during World War II U-class destroyer , destroyers of the Royal Navy launched in 1942–1943 SR U class , 2-6-0 steam locomotives built for the Southern Railway GNRI Class U , 4-4-0 steam locomotives built for the Great Northern Railway, Ireland NER Class U , 0-6-2 steam locomotives built for
52-732: A class of 49 small submarines built just before and during the Second World War . The class is sometimes known as the Undine class, after the first submarine built. A further development was the British V-class submarine of 1942. At the start of the Second World War the U class was, with the British S Class and T class submarines, the Dutch O 21 class and German Type VII class one of
78-473: A constant problem for the class. The boats had a fuel capacity of 38 long tons (39 t) giving a range of 3,800 nmi (7,000 km; 4,400 mi) at 10 kn (19 km/h; 12 mph) on the surface and 120 nmi (220 km; 140 mi) at 2 kn (3.7 km/h; 2.3 mph) submerged; battery recharging required the submarine to surface; in 1944 dummy snorkels were fitted to some boats for anti-submarine warfare training During construction
104-608: A cruiser and another destroyer also sunk before being lost in April 1942. Wanklyn was awarded the Victoria Cross for attacking a well-defended convoy and sinking the Italian liner Conte Rosso on 25 May 1941. Losses in this group were high, only three out of the twelve survived the war. The third group formed the largest group of U-class submarines, comprising 34 vessels ordered in three batches. Losses continued to be high. In June 1940
130-418: A shallow periscope depth could allow the boat to be seen from the air. Hydrophones were fitted, one on each side near the bows facing outwards and one on the conning tower facing aft. Asdic Type 129 was installed forward of the keel from 1937 and two wireless aerials were carried, a jumping aerial on the conning tower for very low frequency signals at periscope depth and a WT mast which could be raised above
156-581: A surface speed of 11.25 kn (20.84 km/h; 12.95 mph) and a submerged speed of 10 kn (19 km/h; 12 mph). The diesels were linked to the propellers by two generators which kept charged the battery of 112 cells under the control room and crew accommodation. Submarine propellers had been designed to perform best on the surface until the Unity-class which was the first submarine design with propellers giving their best performance submerged to reduce propeller noise but "singing propellers" were
182-534: The North Eastern Railway NZR U class , 4-6-0 steam locomotives built for New Zealand Railways Russian locomotive class U , 4-6-0 steam locomotives South African Class U 2-6-2+2-6-2 , steam locomotives Class U special wagon , railway goods wagons U-class Melbourne tram See also [ edit ] UCLASS SR U1 class Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
208-619: The Tyne. Undine was launched on 5 October 1937 and sunk by German minesweepers on 7 January 1940 off Heligoland . The experience gained with the U -class boats was incorporated into the Group two boats of the War Supplementary Emergency Programme, consisting of twelve submarines, of a similar design to the original three. The external torpedo tubes were omitted and the boats had a redesigned stern to reduce cavitation and on some of
234-635: The V-class boats were lost and some did not see service. The boats were named HMS Upshot , HMS Urtica , HMS Vagabond , HMS Variance , HMS Venturer , HMS Vigorous , HMS Viking , HMS Vampire , HMS Varne II , HMS Veldt , HMS Vineyard , HMS Virtue , HMS Visigoth , HMS Vivid , HMS Voracious , HMS Votary , HMS Vox II , HMS Virulent , HMS Volatile , HMS Vortex and HMS Vulpine . HMS Undine (N48) HMS Undine
260-454: The boats a new bow shape was introduced to reduce the bow wave; the hydroplanes were enlarged for better submerged handling. The First World War-vintage 12-pounder was retained but replaced on Unbeaten and Unique by a 3-inch gun. The boats ordered in 1940 and 1941 carried the 3-inch gun and more fuel. Most of the boats were built by Vickers at Barrow-in-Furness. MI5 investigated the loss of Vandal and Untamed during training operations but
286-423: The decision was taken, in view of the anticipated high number of submarines to be ordered, to drop the practice of naming submarines and the vessels were called P31 to P39 , P41 to P49 . At the end of 1942 Winston Churchill ordered that all submarines were to receive names but eight of the U -class boats were lost before they could receive them, whilst on operations with the Royal Navy. The V-class boats were
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#1732858294880312-571: The end of their useful service. The Rear-Admiral Submarines, Noel Laurence , wanted a class of small, inexpensive boats for training, armed with torpedoes for short-range patrols. In March 1934 he approved a specification for a "Small, Simple, Submarine, for Anti-Submarine Training etc". The three Unity -class boats, HMS Undine , Unity and Ursula were ordered on 5 November 1936 from Vickers-Armstrongs , to be built at their Naval Construction Yard in Barrow-in-Furness . According to
338-443: The external tubes, the others without, because the bulge at the bow generated a large bow wave . Depth keeping was more difficult at periscope depth , a rather shallow 12 ft (3.7 m) which was more of a disadvantage than the six-torpedo salvo justified. The sudden loss of weight in the bows when the torpedoes were loosed in salvo made the boat porpoise and break the surface. The three Unity-class boats entered service in
364-541: The final refinement of the U-class submarines, 34 were ordered and 21 were built by Vickers for the War Emergency Programmes of 1941 and 1942, the rest being cancelled. The hull was further lengthened to try to eliminate the singing propellers and the bows were more streamlined. Welding of the hull frames was introduced to use thicker steel for the pressure hull, giving a diving depth of 300 ft (91 m). None of
390-501: The four internal bow torpedo tubes were supplemented by two external tubes in a bulged housing, four reloads being carried for the internal tubes. Ursula carried a 3 in (76 mm) gun but had no hatch for the gun crew, who had to use the conning tower; to compensate for the weight of the gun only eight torpedoes were carried. Just before the war, a second group of twelve vessels were ordered, HMS Unique , HMS Upholder , HMS Upright and HMS Utmost with
416-558: The latter half of 1938. Designed as training vessels, they were effective enough to persuade the Admiralty to build more and to improve their offensive capacity. Ursula was launched on 16 February 1938, was loaned to the Soviet Navy from 1944 to 1949 as V 4 and sold in May 1950 and broken up. Unity was launched on 16 February 1938 and sunk on 29 April 1940 in a collision with SS Atle Jarl off
442-607: The most advanced submarine classes in service. The Royal Navy was limited to no more than 52,700 long tons (53,500 t) of submarines by the London Naval Treaty of 1930. The tonnage limit led to proposals for smaller submarines which was also prompted by trials with larger submarines demonstrating that they were easier to find and lacked manoeuvrability. By coincidence the First World War -vintage H-class submarines used for training in anti-submarine warfare were reaching
468-653: The practise in the First World War but that because of Churchill's views, the Admiralty had decided that it was better to be right than consistent and that naming was to be resumed. After a delay Churchill was told that it was difficult to find sufficient names beginning with U and that the surplus were being named with words beginning with V and a list was sent to Churchill on 27 December 1942. Submarines lost before they could receive names kept their pennant number. The group included submarines that became well-known; Urchin
494-540: The recommendation of the Hopwood Committee of 1926 the boats had names beginning with the same letter in the alphabet. The new boats were the smallest built since the First World War. The U-class boats had a hull of riveted steel, half-an-inch thick for dives to 200 ft (61 m), with the fuel tanks and ballast tanks on the inside. The superstructure and conning tower were built with free-flooding holes and storage for cables, anchors and sundry items. The hull
520-498: The report was kept confidential. In June 1940 the Admiralty had stopped naming submarines and known them by their pennant numbers but on 4 November 1942 the Prime Minister, Winston Churchill, questioned the policy. The First Lord of the Admiralty replied that naming had been dropped to avoid confusion with the big increase in the number of destroyers, which usually had names with the same initial letter. Numbering submarines had been
546-565: The title U class . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=U_class&oldid=1223403341 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages British U-class submarine The British U-class submarines (officially " War Emergency 1940 and 1941 programmes, short hull ") were
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#1732858294880572-487: The water spread the second aerial for conventional wireless signalling. The boats had six ordinary ballast tanks and a quick-diving, Q tank , the ballast tanks, hydroplanes and the rudder being hydraulically operated; the forward hydroplanes were mounted high on the hull and folded upwards for docking. The submarines had two 400 hp (300 kW) Paxman diesel-electric engines generating 615 bhp (459 kW) and electric motors of 825 shp (615 kW) giving
598-526: Was commissioned on 21 August 1938 with the pennant number N48. At the onset of the Second World War, Undine was a member of the 6th Submarine Flotilla. From 26–29 August 1939, the flotilla deployed to its war bases at Dundee and Blyth. Undine was on her fourth war patrol in January 1940 when her sonar failed due to a leak. At 0940 on 7 January, she was attacked by German auxiliary minesweepers M-1201 , M-1204 and M-1207 . She unsuccessfully attacked
624-427: Was a U-class submarine and lead vessel of her class, which is sometimes called the Undine class as a result. The submarine entered service in 1938. Undine performed war patrols during the Second World War and was scuttled after being damaged by German minesweepers off Heligoland on 7 January 1940. Undine was built by Vickers Armstrong , Barrow-in-Furness . She was laid down on 19 February 1937 and
650-411: Was divided by five bulkheads with access from the conning tower; hatches in the torpedo-stowage compartment and in the engine room had drop-down canvas trunks for emergencies. The boats had an 8 in (200 mm) bifocal periscope with high/low magnification for searching and a 6 in (150 mm) low magnification periscope for attack. The periscopes could rise 12 ft (3.7 m) but such
676-526: Was transferred to the Polish Navy as ORP Sokół and sank 55,000 long tons (56,000 t) of Axis shipping. In the 16-month operational career of HMS Upholder ( Lieutenant-Commander Malcolm Wanklyn ) in the Mediterranean, Upholder carried out 24 patrols and sank around 119,000 long tons (121,000 t) of Axis ships, consisting of three U-boats, a destroyer, 15 merchant ships with possibly
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