Type U 27 submarine

Class overview
Builders	Kaiserliche Werft Danzig
Operators	Imperial German Navy
Preceded by	Type U 23
Succeeded by	Type U 31
Completed	4
Lost	3
General characteristics [1]
Displacement	675  t (664 long tons) surfaced 876 t (862 long tons) submerged
Length	64.70 m (212 ft 3 in) (o/a)
Beam	6.32 m (20 ft 9 in)
Draught	3.48 m (11 ft 5 in)
Speed	16.7 knots (30.9 km/h; 19.2 mph) surfaced 9.8 knots (18.1 km/h; 11.3 mph) submerged
Range	8,420  nmi (15,590 km; 9,690 mi) at 8 knots (15 km/h; 9.2 mph) surfaced 85 nmi (157 km; 98 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged
Test depth	50 m (164 ft)
Complement	4 officers, 31 enlisted
Armament	4 × 50 cm (19.7 in) torpedo tubes 1 × 8.8 cm (3.5 in) SK L/30 deck gun

Type U 27 was a class of U-boats built during World War I by the Kaiserliche Marine. The four Type U 27 U-boats were ordered on 12 February 1912. They were very similar to the preceding Type U 19 and Type U 23. ^[2]

Design

Type U 27s had an overall length of 64.70 m (212 ft 3 in) The boats' beam was 6.32 m (20 ft 9 in), the draught was 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 685 tonnes (674 long tons) when surfaced and 867 t (853 long tons) when submerged. ^{[3] [4]}

Type U 27s were fitted with two MAN 6-cylinder four-stroke diesel engines with a total of 2,000 metric horsepower (1,471  kW ; 1,973  bhp ) for use on the surface and two AEG double-acting electric motors with a total of 880 kW (1,196 PS; 1,180 shp) for underwater use. These engines powered two shafts, which gave the boats a top surface speed of 16.7 knots (30.9 km/h; 19.2 mph), and 9.8 knots (18.1 km/h; 11.3 mph) when submerged. Cruising range was 8,420 nautical miles (15,590 km; 9,690 mi) at 8 knots (15 km/h; 9.2 mph) on the surface and 85 nautical miles (157 km; 98 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged. ^[3] Constructional diving depth ^[a] was 50 m (164 ft 1 in). ^{[5] [4]}

The U-boats were armed with four 50 cm (20 in) torpedo tubes, two fitted in the bow and two in the stern, and carried six torpedoes. All boats received initially one or two 8.8 cm (3.5 in) SK L/30 deck guns. U-30 had its sole deck gun replaced in 1916 with a 10.5 cm (4.1 in) SK L/45 gun. The boats' complement was 4 officers and 31 enlisted. ^{[3] [4]}

Ships

Name	Launched [6]	Commissioned [6]	Merchant ships sunk (nbr / GRT ) [6]	Warships sunk ( nbr / tons ) [6]	Fate [3]
U-27	14 July 1913	8 May 1914	9 / 29,402	2 / 6,290	Sunk on 15 August 1915 in the English Channel.
U-28	30 August 1913	26 July 1914	39 / 93,782	none	Sunk on 2 September 1917 in the Arctic Ocean.
U-29	11 Oktober 1913	1 Augustus 1914	4 / 12,934	none	Sunk on 18 March in the North Sea.
U-30	15 November 1913	26 August 1914	26 / 47,383	none	Sunk on 22 June 1915 in an accident on the Ems river. Raised in 1918, surrendered and scrapped in 1919–1920 at Blyth.

Footnotes

Notes

1. Constructional diving depth had a safety factor of 2.5, which meant that crushing depth was 2.5 times construction diving depth. ^[5]

Citations

1. Gröner 1991, pp. 6–7.
2. Rössler 1981, p. 28.
3. Möller & Brack 2004, p. 25.
4. Gröner 1991, p. 6.
5. Rössler 1981, p. 26.
6. Herzog 1993, p. 67.

Bibliography

• Gröner, Erich; Jung, Dieter; Maass, Martin (1991). German Warships 1815–1945, U-boats and Mine Warfare Vessels. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN   0-85177-593-4.
• Herzog, Bodo (1993). Deutsche U-Boote : 1906 - 1966[German U-boats : 1906 - 1966] (in German). Erlangen: Müller. ISBN   9783860700365.
• Möller, Eberhard; Brack, Werner (2004). The Encyclopedia of U-Boats. London: Chatham. ISBN   1-85367-623-3.
• Rössler, Eberhard (1981). The U-boat: The evolution and technical history of German submarines. London: Cassell & Co. ISBN   0-304-36120-8.