SM U-36

U-36 was laid down on 2 January 1913 at Germaniawerft in Kiel. She was launched on 6 June 1914 and commissioned on 14 November 1914, under the command of Kapitänleutnant Ernst Graeff.[2] During February 1915, she carried out acceptance trials at Kiel,[2] and was attached to the 2d Half-Flotilla in the North Sea in March.[2]

German Type U 31 submarines were double-hulled ocean-going submarines similar to Type 23 and Type 27 subs in dimensions and differed only slightly in propulsion and speed. They were considered very good high sea boats with average manoeuvrability and good surface steering.[3]

U-36 had an overall length of 64.70 m (212 ft 3 in), her pressure hull was 52.36 m (171 ft 9 in) long. The boat's beam was 6.32 m (20 ft 9 in) (o/a), while the pressure hull measured 4.05 m (13 ft 3 in). Type 31s had a draught of 3.56 m (11 ft 8 in) with a total height of 7.68–8.04 m (25 ft 2 in–26 ft 5 in). The boats displaced a total of 971 tonnes (956 long tons); 685 t (674 long tons) when surfaced and 878 t (864 long tons) when submerged.[3]

U-36 was fitted with two Germania 6-cylinder two-stroke diesel engines with a total of 1,850 metric horsepower (1,361 kW; 1,825 bhp) for use on the surface and two Siemens-Schuckert double-acting electric motors with a total of 1,200 PS (883 kW; 1,184 shp) for underwater use. These engines powered two shafts each with a 1.60 m (5 ft 3 in) propeller, which gave the boat a top surface speed of 16.4 knots (30.4 km/h; 18.9 mph), and 9.7 knots (18.0 km/h; 11.2 mph) when submerged. Cruising range was 8,790 nautical miles (16,280 km; 10,120 mi) at 8 knots (15 km/h; 9.2 mph) on the surface, and 80 nmi (150 km; 92 mi) at 5 knots (9.3 km/h; 5.8 mph) under water. Diving depth was 50 m (164 ft 1 in).[3]

The U-boat was armed with four 50 cm (20 in) torpedo tubes, two fitted in the bow and two in the stern, and carried 6 torpedoes. Additionally U-36 was equipped in 1915 with two 8.8 cm (3.5 in) Uk L/30 deck guns. The boat's complement was 4 officers and 31 enlisted.[3]

SM U-36's movements and operations were monitored and reported by British Naval Intelligence, better known as "Room 40".[2] Her first war patrol was in Heligoland Bight from 29 to 30 March 1915; she reported no sinkings during this time.[2] On 23 April, she returned to Heligoland Bight, apparently from a North Sea patrol.[2][Note 2]

She departed on 29 April, bound again for the North Sea, where she sank the 1,966-ton Danish steamer Lilian Drost on 8 May, captured the 1,241-ton Swedish steamer Björn on 10 May as a prize, while capturing and releasing the 654-ton Dutch steamer Niobe the same day.[2]

U-36 returned to her North Sea station on 17 July. Operating off the north and northwest coast of Scotland, she sank three steamers and almost a dozen smaller vessels. On 22 July, the 3,644-ton Russian Rubonia fell victim. That same day, U-36 also attacked a group of fishing vessels west of the Orkney Islands, sinking nine small trawlers and two sailing vessels, while taking one prize. The following day, the 1,505-ton Frenchman Danae was stopped according to prize rules and sunk, and the 3,819-ton Norwegian Fimreite was sunk as well.[2]

On the day she was sunk, U-36 intercepted and captured the American windjammer Pass of Balmaha, bearing a cargo of cotton intended for Russia and en route to Kirkwall to be inspected by British authorities. An ensign from U-36 was left aboard the windjammer to ensure her successful passage to Cuxhaven. Pass was refitted as a merchant raider and re-christened Seeadler, commanded by Count Felix von Luckner,[4] soon to become famous for her naval exploits in the Atlantic and Pacific.

• Room 40

• Beesly, Patrick (1982). Room 40: British Naval Intelligence 1914–1918. London: H Hamilton. ISBN 978-0-241-10864-2.
• Fitzsimons, Bernard, ed. The Illustrated Encyclopedia of 20th Century Weapons and Warfare, "U-Boats (1905–18), Volume 23, p. 2534. London: Phoebus Publishing, 1978.
• Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.*Halpern, Paul G. (1995). A Naval History of World War I. New York: Routledge. ISBN 978-1-85728-498-0.
• Bodo Herzog: Deutsche U-Boote 1906-1966. Manfred Pawlak Verlags GmbH, Herrschingen 1990, ISBN 3-88199-687-7
• Paul Kemp: Die deutschen und österreichischen U-Boot Verluste in beiden Weltkriegen. Urbes Verlag Hans Jürgen Hansen, Gräfelfing vor München 1998, ISBN 3-924896-43-7
• Koerver, Hans Joachim (2008). Room 40: German Naval Warfare 1914–1918. Vol I., The Fleet in Action. Steinbach: LIS Reinisch. ISBN 978-3-902433-76-3.
• Koerver, Hans Joachim (2009). Room 40: German Naval Warfare 1914–1918. Vol II., The Fleet in Being. Steinbach: LIS Reinisch. ISBN 978-3-902433-77-0.
• Roessler, Eberhard (1997). Die Unterseeboote der Kaiserlichen Marine. Bonn: Bernard & Graefe. ISBN 978-3-7637-5963-7.
• Schroeder, Joachim (2002). Die U-Boote des Kaisers. Bonn: Bernard & Graefe. ISBN 978-3-7637-6235-4.
• Spindler, Arno (1966) [1932]. Der Handelskrieg mit U-Booten. 5 Vols. Berlin: Mittler & Sohn. Vols. 4+5, dealing with 1917+18, are very hard to find: Guildhall Library, London, has them all, also Vol. 1-3 in an English translation: The submarine war against commerce.

• Information on British Q-ships like Prince Charles.
• Helgason, Guðmundur. "WWI U-boat Types: Type U 31". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net.
• Helgason, Guðmundur. "WWI U-boats: U 36". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net.
• A 44 min. film from 1917 about a cruise of the German submarine U-35. A German propaganda film without dead or wounded; many details about submarine warfare in World War I.
• 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.