SM U-69 was a Type U 66 submarine or U-boat for the German Imperial Navy () during the First World War. She had been laid down in February 1914 as U-10 the fourth boat of the U-7 class for the Austro-Hungarian Navy ( or ) but was sold to Germany, along with the others in her class, in November 1914.
The submarine was ordered as U-10 from Germaniawerft of Kiel as the first of five boats of the U-7 class for the Austro-Hungarian Navy. After the outbreak of World War I in August 1914, the Austro-Hungarian Navy became convinced that none of the submarines of the class could be delivered to the Adriatic via Gibraltar. As a consequence, the entire class, including U-10, was sold to the German Imperial Navy in November 1914. Under German control, the class became known as the U 66 type and the boats were renumbered; U-10 became U-69, and all were redesigned and reconstructed to German specifications. U-69 was launched in June 1915 and commissioned in September. As completed, she displaced , surfaced, and , submerged. The boat was long and was armed with five torpedo tubes and a deck gun.
As a part of the 4th Flotilla, U-69 sank 31 ships with a combined gross register tonnage of 102,875 in five war patrols. U-69 left Emden on her sixth patrol on 9 July 1917 for operations off Ireland. On 11 July, U-69 reported her position off Norway but neither she nor any of her crew were ever heard from again. British records say that U-69 was sunk by destroyer on 12 July, but a German postwar study cast doubt on this. U-69s fate is officially unknown.
Design and construction After the Austro-Hungarian Navy had competitively evaluated three foreign submarine designs, it selected the Germaniawerft 506d design, also known as the Type UD, for its new U-7 class of five submarines.Gardiner, p. 340. The Navy ordered five boats on 1 February 1913.Gardiner, p. 343.
The U-7 class was seen by the Austro-Hungarian Navy as an improved version of its U-3 class, which was also a Germaniawerft design.The U-3-class submarines, however, were less than half the displacement and nearly shorter than the U-7 design. See: Gardiner, pp. 342–43. As designed for the Austro-Hungarian Navy, the boats were to displace on the surface and while submerged. The doubled-hulled boats were to be long overall with a beam of and a draft of . The Austrian specifications called for two shafts with twin diesel engines ( total) for surface running at up to , and twin electric motors ( total) for a maximum of when submerged. The boats were designed with five torpedo tubes; four located in the bow, one in the stern. The boats' armament was to also include a single deck gun.
U-10 was laid down on 7 February 1914, and her construction was slated to be complete within 29 to 33 months.
Neither U-10 nor any of her sister boats were complete when World War I began in August 1914.Guðmundur Helgason. WWI U-boats: U 66, WWI U-boats: U 67, WWI U-boats: U 68, WWI U-boats: U 69, WWI U-boats: U 70. U-Boat War in World War I. Uboat.net. Retrieved on 9 December 2008. With the boats under construction at Kiel, the Austrians became convinced that it would be impossible to take delivery of the boats, which would need to be towed into the Mediterranean past Gibraltar, a British territory.The Austro-Hungarian Navy's Germaniawerft-built U-3 class boats had been towed from Kiel to Pola via Gibraltar in 1909. See: Sieche, p. 19. As a result, U-10 and her four sisters were sold to the Imperial German Navy on 28 November 1914.In April 1915, just five months later, the German successfully entered the Mediterranean through the Straits of Gibraltar, proving that delivery would have been possible after all. See: Gardiner, p. 343.
U-10 was renumbered by the Germans as U-69 when her class was redesignated as the Type U 66. The Imperial German Navy had the submarines redesigned and reconstructed to German standards, which increased the surface displacement by and the submerged by . The torpedo load was increased by a third, from 9 to 12, and the deck gun was upgraded from the gun originally specified to an Uk L/30 one.
Service career U-69 was launched on 24 June 1915. On 4 September, SM U-69 was commissioned into the Imperial German Navy under the command of Kapitänleutnant Ernst Wilhelms. On 4 March 1916, U-69 was assigned to the IV. U-Halbflotille.Tarrant, p. 34.
U-69 successfully completed five war patrols in which she sank 31 ships with a combined a total of . U-69s most successful month for number of ships sunk was April 1916, when she sank eight ships of 21,051 GRT in a span of six days. The month with the highest tonnage sunk was June 1917 when she sank five ships of 29,808 GRT in a nine-day span; nearly half of that total came from one ship, the 13,441 GRT British armed merchant cruiser sunk on 14 June. Avenger had been patrolling off the Shetland Islands and was returning to Scapa Flow, when she was struck by a single torpedo on the port side. The ship began listing heavily and non-essential crew were evacuated while destroyers arrived and took her under tow. Despite strenuous efforts to save her, Avenger foundered ten hours after being hit when her internal bulkheads collapsed. One man was killed in the attack.Hepper, p. 93.
U-69 began her sixth and final patrol on 9 July when she departed from Emden, destined for operations off Ireland. U-69s position report at 02:30 on 11 July reported that she was south of Lindesnes, Norway, and was the last known contact with U-69. According to author Dwight Messimer, two British sources report that sank U-69 at position on 12 July. An observer in a kite balloon deployed by Patriot spotted a surfaced U-boat at 07:00. The U-boat submerged and Patriot hunted the submarine until noon, when it loosed two depth charges that brought thick brown oil to the surface. A postwar study by Germany cast doubt on whether or not the submarine attacked by Patriot was U-69. Officially, her fate remains unknown.Messimer, p. 88.
Summary of raiding history DateNameNationalityTonnage(GRT)Fate15 April 1916Fairport3,838Sunk15 April 1916Schwanden844Sunk16 April 1916Glendoon1,918Sunk16 April 1916Harrovian4,309Sunk16 April 1916Papelera1,591Sunk17 April 1916Ernest Reyer2,708Sunk18 April 1916Ravenhill1,826Sunk20 April 1916Cairngowan4,017Sunk11 July 1916HMT Era168Sunk20 October 1916Cabotia4,309Sunk24 October 1916Sola3,057Sunk26 October 1916North Wales4,072Sunk26 October 1916Rappahannock3,871Sunk2 November 1916Spero1,132Sunk3 November 1916Bertha591Sunk20 April 1917Annapolis4,567Sunk25 April 1917Hesperides3,393Sunk26 April 1917Rio Lages3,591Sunk26 April 1917Vauxhall3,629Sunk1 May 1917Rockingham4,555Sunk2 May 1917Troilus7,625Sunk29 May 1917Argo123Sunk29 May 1917Ines261Sunk29 May 1917Consul N. Nielsen1,395Sunk31 May 1917Esneh3,247Sunk3 June 1917Luisa1,648Damaged6 June 1917Parthenia5,160Sunk8 June 1917Enidwen3,594Sunk8 June 1917Saragossa3,541Sunk13 June 1917Kelvinbank4,072Sunk14 June 1917Avenger13,441Sunk24 July 1917Mikelis2,430Sunk
Notes
References
Bibliography
External links
Photos of cruises of German submarine U-54 in 1916-1918. A 44 min. German film from 1917 about a cruise of the German submarine U-35. Room 40: original documents, photos and maps about World War I German submarine warfare and British Room 40 Intelligence from The National Archives, Kew, Richmond, UK.