SM U-91
| History | |
|---|---|
 German Empire | |
| Name: | U-91 |
| Ordered: | 23 June 1915 |
| Builder: | Kaiserliche Werft Danzig |
| Yard number: | 35 |
| Laid down: | 1 August 1916 |
| Launched: | 14 April 1917 |
| Commissioned: | 17 September 1917 |
| Fate: | Surrendered 26 November 1918 |
| General characteristics [1] | |
| Class and type: | German Type U 87 submarine |
| Displacement: |
|
| Length: |
|
| Beam: |
|
| Height: | 9.35 m (30 ft 8 in) |
| Draught: | 3.88 m (12 ft 9 in) |
| Installed power: | |
| Propulsion: | 2 shafts, 2 × 1.66 m (5 ft 5 in) propellers |
| Speed: |
|
| Range: |
|
| Test depth: | 50 m (164 ft 1 in) |
| Complement: | 4 officers, 32 enlisted |
| Armament: |
|
| Service record | |
| Part of: |
|
| Commanders: |
|
| Operations: | 8 patrols |
| Victories: |
|
SM U-91[Note 1] was one of the 329 submarines serving in the Imperial German Navy in World War I. U-91 was engaged in the naval warfare and took part in the First Battle of the Atlantic.[3]
Design
German Type U 87 submarines were preceded by the shorter Type U 81 submarines. U-91 had a displacement of 757 tonnes (745 long tons) when at the surface and 998 tonnes (982 long tons) while submerged.[1] It had a total length of 215 ft 11 in (65.81 m), a pressure hull length of 164 ft 3 in (50.06 m), a beam of 20 ft 4 in (6.20 m), a height of 30 ft 8 in (9.35 m), and a draught of 12 ft 9 in (3.89 m). The submarine was powered by two 2,400 metric horsepower (1,800 kW; 2,400 shp) engines for use while surfaced, and two 1,200 metric horsepower (880 kW; 1,200 shp) engines for use while submerged. It had two shafts and two 1.66 m (5.4 ft) propellers. It was capable of operating at depths of up to 50 metres (160 ft).[1]
The submarine had a maximum surface speed of 16.8 knots (31.1 km/h; 19.3 mph) and a maximum submerged speed of 9.1 knots (16.9 km/h; 10.5 mph).[1] When submerged, it could operate for 56 nautical miles (104 km; 64 mi) at 5 knots (9.3 km/h; 5.8 mph); when surfaced, it could travel 11,380 nautical miles (21,080 km; 13,100 mi) at 8 knots (15 km/h; 9.2 mph). U-91 was fitted with four 50 centimetres (20 in) torpedo tubes (two at the bow and two at the stern), ten to twelve torpedoes, one 10.5 centimetres (4.1 in) deck machine gun, and one 8.8 centimetres (3.5 in) deck machine gun. It had a complement of thirty-six (thirty-two crew members and four officers).[1]
Summary of raiding history
| Date | Name | Nationality | Tonnage[Note 2] | Fate[4] |
|---|---|---|---|---|
| 24 December 1917 | Elmleaf |  United Kingdom |
5,948 | Damaged |
| 28 December 1917 | Robert Eggleton | United Kingdom |
2,274 | Sunk |
| 2 January 1918 | Boston City | United Kingdom |
2,711 | Sunk |
| 4 January 1918 | Otto |  United Kingdom |
139 | Sunk |
| 5 January 1918 | Knightsgarth | United Kingdom |
2,889 | Sunk |
| 7 January 1918 | Premier | United Kingdom |
89 | Sunk |
| 19 February 1918 | Beacon Light | United Kingdom |
2,768 | Sunk |
| 22 February 1918 | Haileybury | United Kingdom |
2,888 | Sunk |
| 23 February 1918 | Birchleaf | United Kingdom |
5,873 | Damaged |
| 23 February 1918 | British Viscount | United Kingdom |
3,287 | Sunk |
| 24 February 1918 | Renfrew | United Kingdom |
3,830 | Sunk |
| 2 March 1918 | Bessy | United Kingdom |
60 | Sunk |
| 20 April 1918 | Florrieston | United Kingdom |
3,366 | Sunk |
| 20 April 1918 | Lowther Range | United Kingdom |
3,926 | Sunk |
| 21 April 1918 | Landonia | United Kingdom |
2,504 | Sunk |
| 21 April 1918 | Normandiet | United Kingdom |
1,843 | Sunk |
| 22 April 1918 | Baron Herries | United Kingdom |
1,610 | Sunk |
| 26 April 1918 | Ethel | United Kingdom |
100 | Sunk |
| 27 April 1918 | Gresham | United Kingdom |
3,774 | Sunk |
| 27 April 1918 | Walpas |  Russian Empire |
312 | Sunk |
| 28 April 1918 | Damao |  Portugal |
5,668 | Sunk |
| 28 April 1918 | Oronsa | United Kingdom |
8,075 | Sunk |
| 1 July 1918 | Westmoor | United Kingdom |
4,329 | Sunk |
| 6 July 1918 | Port Hardy | United Kingdom |
6,533 | Sunk |
| 9 July 1918 | Silvia | _crowned.svg.png){kind=small} Kingdom of Italy |
3,571 | Sunk |
| 13 July 1918 | Badagri | United Kingdom |
2,956 | Sunk |
| 16 July 1918 | Fisherman | United Kingdom |
136 | Sunk |
| 25 July 1918 | Tippecanoe |  United States |
6,187 | Sunk |
| 1 October 1918 | Therese et Marthe |  France |
32 | Sunk |
| 2 October 1918 | Maia | France |
185 | Sunk |
| 2 October 1918 | Marie Emmanuel | France |
32 | Sunk |
| 2 October 1918 | Ave Maris Stella | France |
22 | Sunk |
| 4 October 1918 | Mercedes |  Spain |
2,164 | Sunk |
| 5 October 1918 | Heathpark | United Kingdom |
2,205 | Sunk |
| 5 October 1918 | Erindring | United Kingdom |
1,229 | Sunk |
| 8 October 1918 | Cazengo | Portugal |
3,009 | Sunk |
| 9 October 1918 | Pierre | France |
354 | Sunk |
| 11 October 1918 | Luksefjell |  Norway |
2,007 | Sunk |
| 14 October 1918 | Bayard | France |
55 | Sunk |
References
Notes
- ↑ "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.
- ↑ Tonnages are in gross register tons
Citations
- 1 2 3 4 5 Gröner 1991, pp. 12-14.
- ↑ Helgason, Guðmundur. "WWI U-boat commanders: Alfred von Glasenapp (Royal House Order of Hohenzollern)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 21 January 2015.
- ↑ Helgason, Guðmundur. "WWI U-boats: U 91". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 25 January 2010.
- ↑ Helgason, Guðmundur. "Ships hit by U 91". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 21 January 2015.
Bibliography
- 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.