SM UB-28

SM UB-28 was a German Type UB II submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. The U-boat was ordered on 30 April 1915 and launched on 20 December 1915. She was commissioned into the German Imperial Navy on 27 December 1915 as SM UB-28.[Note 1]

For other ships with the same name, see German submarine U-28.

SM UB-45, a u-boat similar to UB-28
History
German Empire
Name:	UB-28
Ordered:	30 April 1915[1]
Builder:	AG Weser, Bremen[1]
Cost:	1,291,000 German Papiermark
Yard number:	242[1]
Launched:	20 December 1915[1]
Commissioned:	27 December 1915[2]
Fate:	surrendered 24 November 1918[2]
General characteristics y
Class and type:	German Type UB II submarine
Displacement:	265 t (261 long tons) surfaced 291 t (286 long tons) submerged
Length:	36.13 m (118 ft 6 in) o/a 27.13 m (89 ft) pressure hull
Beam:	4.36 m (14 ft 4 in) o/a 3.85 m (13 ft) pressure hull
Draught:	3.66 m (12 ft)
Propulsion:	1 × propeller shaft 2 × 6-cylinder diesel engine, 270 PS (200 kW; 270 bhp) 2 × electric motor, 280 PS (210 kW; 280 shp)
Speed:	8.90 knots (16.48 km/h; 10.24 mph) surfaced 5.72 knots (10.59 km/h; 6.58 mph) submerged
Range:	7,200 nmi (13,300 km; 8,300 mi) at 5 knots (9.3 km/h; 5.8 mph) surfaced 45 nmi (83 km; 52 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth:	50 m (160 ft)
Complement:	2 officers, 21 men
Armament:	2 × 50 cm (19.7 in) torpedo tubes 4 × torpedoes (later 6) 1 × 5 cm SK L/40 gun
Notes:	30-second diving time
Service record
Commanders:	Oblt.z.S. Ernst Rosenow[3] 27 December 1915 – 13 January 1916
Operations:	No patrols
Victories:	None

UB-28 was surrendered to Britain in accordance with the requirements of the Armistice with Germany on 24 November 1918. She was ultimately broken up at Bo'ness in 1919-20.[2]

Design

A German Type UB II submarine, UB-28 had a displacement of 265 tonnes (261 long tons) when at the surface and 291 tonnes (286 long tons) while submerged. She had a total length of 36.13 m (118 ft 6 in), a beam of 4.36 m (14 ft 4 in), and a draught of 3.66 m (12 ft). The submarine was powered by two Benz six-cylinder diesel engines producing a total 267 metric horsepower (263 shp; 196 kW), two Siemens-Schuckert electric motors producing 280 metric horsepower (210 kW; 280 shp), and one propeller shaft. She was capable of operating at depths of up to 50 metres (160 ft).[2]

The submarine had a maximum surface speed of 8.9 knots (16.5 km/h; 10.2 mph) and a maximum submerged speed of 5.72 knots (10.59 km/h; 6.58 mph). When submerged, she could operate for 45 nautical miles (83 km; 52 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 7,200 nautical miles (13,300 km; 8,300 mi) at 5 knots (9.3 km/h; 5.8 mph). UB-28 was fitted with two 50 centimetres (20 in) torpedo tubes, four torpedoes, and one 5 cm (2.0 in) SK L/40 deck gun. She had a complement of twenty-one crew members and two officers and a thirty-second dive time.[2]

Notes

1. "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.

References

1. Rössler 1979, p. 54.
2. Gröner 1991, pp. 23-25.
3. Helgason, Guðmundur. "WWI U-boat commanders: Ernst Rosenow". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 8 March 2015.

Bibliography

• Bendert, Harald (2000). Die UB-Boote der Kaiserlichen Marine, 1914-1918. Einsätze, Erfolge, Schicksal (in German). Hamburg: Verlag E.S. Mittler & Sohn GmbH. ISBN 3-8132-0713-7.CS1 maint: ref=harv (link)
• 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.
• Rössler, Eberhard (1979). U-Bootbau bis Ende des 1. Weltkrieges, Konstruktionen für das Ausland und die Jahre 1935 – 1945. Die deutschen U-Boote und ihre Werften (in German). I. Munich: Bernard & Graefe. ISBN 3-7637-5213-7.CS1 maint: ref=harv (link)