Type 81 was a class of U-boats built during World War I by the Kaiserliche Marine.

Class overview
BuildersGermaniawerft, Kiel
Operators Imperial German Navy
Preceded byType UE I
Succeeded byType U 87
Completed6
Lost4
General characteristics [1]
Displacement
  • 808 t (795 long tons) surfaced
  • 946 t (931 long tons) submerged
Length
Beam
  • 6.30 m (20 ft 8 in) (oa)
  • 4.15 m (13 ft 7 in) (pressure hull)
Height8.00 m (26 ft 3 in)
Draught4.02 m (13 ft 2 in)
Installed power
  • 2 × 2,400 PS (1,765 kW; 2,367 shp) surfaced
  • 2 × 1,200 PS (883 kW; 1,184 shp) submerged
Propulsion2 shafts, 2 × 1.70 m (5 ft 7 in) propellers
Speed
  • 16.8 knots (31.1 km/h; 19.3 mph) surfaced
  • 9.1 knots (16.9 km/h; 10.5 mph) submerged
Range
  • 11,220 nmi (20,780 km; 12,910 mi) at 8 knots (15 km/h; 9.2 mph) surfaced
  • 56 nmi (104 km; 64 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged
Test depth50 m (164 ft 1 in)
Complement4 officers, 31 enlisted
Armament

Design

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Type 81 U-boats carried 12 torpedoes and had various arrangements of deck guns. U 81 to U 83 had one 10.5-centimetre (4.1 in) deck gun with 140-240 rounds. U 84 - U 86 were constructed with two 8.8-centimetre (3.5 in) deck guns. In 1917, U 84 - U 86 were converted to a carry one 10.5 cm and one 8.8 cm deck gun[2] and carried 240 rounds.

They carried a crew of four officers and 31 men and had excellent seagoing abilities with a cruising range of around 11,220 nautical miles (20,780 km; 12,910 mi).[2] Many arrangements from the Type 81 and the next two types were also seen on the World War II Type IX U-boats when their design work took place 20 years later.[citation needed]

Compared to the previous type 63, the 81s were 1.7 metres (5 ft 7 in) longer, while the pressure hull remained the same.[3] They were .3 knots (0.56 km/h; 0.35 mph) faster on the surface, and .1 knots (0.19 km/h; 0.12 mph) faster submerged and increased range by 1,030 nautical miles (1,910 km; 1,190 mi) to 11,200  nmi at 8 knots. They carried 12 torpedoes instead of 6, and by 1917 all type 87s had the larger 10.5 cm deck gun versus the twin 8.8 cm on the 63s. Crew size was decreased by 1 to 35.[citation needed]

Compared to the following type 87, the 81s were 4.26 metres (14.0 ft) longer, yet 5 tons lighter.[3] Their range was 180 miles shorter, but speed was 1.2 knots (2.2 km/h; 1.4 mph) faster on the surface and .5 knots (0.93 km/h; 0.58 mph) faster submerged. The most significant difference was the addition of 4 more torpedoes and 2 additional bow tubes on the type 87. Type 87 also got the additional crew member back and numbered 36 again.[citation needed]

Service history

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Type 81 boats were responsible for sinking 3.537% of all Allied shipping sunk during the war, accounting for a total of 427,247 combined tons. They also damaged 89,522 combined tons, and captured 3,462 combined tons.[citation needed]

Boat Sunk Damaged Captured Total
U-81 88,483 3,481 0 91,964
U-82 108,310 32,914 0 141,224
U-83 6,450 3,207 0 9,657
U-84 86,196 42,149 3,462 131,807
U-85 20,225 7,608 0 27,883
U-86 117,583 163 0 117,746
Totals 427,247 89,522 3,462 520,281

References

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  1. ^ Gröner 1991, pp. 12–14.
  2. ^ a b Gröner 1991, p. 12.
  3. ^ a b Helgason, Guðmundur. "WWI U-boat Types: Type U 63". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.

Bibliography

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  • Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.

Further reading

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  • Rössler, Eberhard (2001). The U-boat: The evolution and technical history of German submarines. London: Cassell & Co. ISBN 0-304-36120-8.
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  • Helgason, Guðmundur. "WWI U-boat Types: Type U 81". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.