# SM U-87

SM U-87 was one of the 329 submarines serving in the Imperial German Navy (Kaiserliche Marine) in World War I. U-87 was engaged in the naval warfare and took part in the First Battle of the Atlantic. She sank some 22 merchant vessels before 25 December 1917, when HMS Buttercup rammed U-87 in the Irish Sea and depth-charged her. Then the P-class sloop P.56 sank her. U-87's entire crew of 44 were lost.

## Design

Type U 87 submarines were preceded by the shorter Type U 81 submarines. The first of its type, U-87 had a displacement of 757 tonnes (745 long tons) when at the surface and 998 tonnes (982 long tons) while submerged. She had a total length of 65.80 m (215 ft 11 in), a pressure hull length of 50.07 m (164 ft 3 in), a beam of 6.20 m (20 ft 4 in), a height of 9.35 m (30 ft 8 in), and a draught of 3.88 m (12 ft 9 in). 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. She had two propeller shafts. She was capable of operating at depths of up to 50 metres (160 ft).
The submarine had a maximum surface speed of 15.6 knots (28.9 km/h; 18.0 mph) and a maximum submerged speed of 8.6 knots (15.9 km/h; 9.9 mph). When submerged, she could operate for 56 nautical miles (104 km; 64 mi) at 5 knots (9.3 km/h; 5.8 mph); when surfaced, she could travel 11,380 nautical miles (21,080 km; 13,100 mi) at 8 knots (15 km/h; 9.2 mph). U-87 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 cm (4.1 in) SK L/45 deck gun, and one 8.8 cm (3.5 in) SK L/30 deck gun. She had a complement of thirty-six (thirty-two crew members and four officers).

## Summary of raiding history

| Date | Name | Nationality | Tonnage | Fate |
| 23 May 1917 | Bernisse | Netherlands | 951 | Damaged |
| 23 May 1917 | Elve | Netherlands | 962 | Sunk |
| 26 May 1917 | Lucipara | Russia | 1,943 | Sunk |
| 26 May 1917 | Saint Mirren | United Kingdom | 1,956 | Sunk |
| 30 May 1917 | Bathurst | United Kingdom | 2,821 | Sunk |
| 30 May 1917 | Hanley | United Kingdom | 3,331 | Sunk |
| 2 June 1917 | Eliofilo | Italy | 3,583 | Sunk |
| 2 June 1917 | Mississippi | France | 6,687 | Damaged |
| 4 July 1917 | Loch Katrine | United Kingdom | 151 | Sunk |
| 8 July 1917 | Valetta | United Kingdom | 5,871 | Sunk |
| 10 July 1917 | Seang Choon | United Kingdom | 5,807 | Sunk |
| 11 July 1917 | Kioto | United Kingdom | 6,182 | Sunk |
| 12 July 1917 | Castleton | United Kingdom | 2,395 | Sunk |
| 16 July 1917 | Tamele | United Kingdom | 3,932 | Sunk |
| 19 July 1917 | Artensis | Norway | 1,788 | Sunk |
| 21 July 1917 | Coniston Water | United Kingdom | 3,738 | Sunk |
| 19 August 1917 | Eika II | Norway | 1,268 | Sunk |
| 21 August 1917 | Oslo | United Kingdom | 2,296 | Sunk |
| 22 August 1917 | Alexander Shukoff | Denmark | 1,652 | Sunk |
| 27 August 1917 | Anna | Denmark | 1,211 | Sunk |
| 27 August 1917 | Aurora | Denmark | 768 | Sunk |
| 13 December 1917 | Little Gem | United Kingdom | 114 | Sunk |
| 24 December 1917 | Daybreak | United Kingdom | 3,238 | Sunk |
| 25 December 1917 | Agberi | United Kingdom | 4,821 | Sunk |

## Fate and discovery

In August 2017, researchers from Bangor University in Wales announced they had discovered the sunken wreck of U-87 while conducting multibeam surveys 10 miles northwest of Bardsey Island as part of the marine renewable energy SEACAMS 2 project. Detailed sonar images reveal the wreck to be lying in one piece with what appears to be a large area of damage near the conning tower, presumably caused by in the ramming collision by escort P.56.