# SM UC-71

SM UC-71 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. The U-boat was ordered on 12 January 1916 and was launched on 12 August 1916. She was commissioned into the German Imperial Navy on 28 November 1916 as SM UC-71. In 19 patrols UC-71 was credited with sinking 63 ships, either by torpedo or by mines laid. UC-71 sank on 20 February 1919 in the North Sea while on her way to be surrendered. Discovery a century later of her wreck with all hatches open suggested she had been deliberately scuttled by her own crew (all of whom survived).

## Design

A Type UC II submarine, UC-71 had a displacement of 427 tonnes (420 long tons) when at the surface and 508 tonnes (500 long tons) while submerged. She had a length overall of 50.35 m (165 ft 2 in), a beam of 5.22 m (17 ft 2 in), and a draught of 3.64 m (11 ft 11 in). The submarine was powered by two six-cylinder four-stroke diesel engines each producing 300 metric horsepower (220 kW; 300 shp) (a total of 600 metric horsepower (440 kW; 590 shp)), two electric motors producing 620 metric horsepower (460 kW; 610 shp), and two propeller shafts. She had a dive time of 48 seconds and was capable of operating at a depth of 50 metres (160 ft).
The submarine had a maximum surface speed of 12 knots (22 km/h; 14 mph) and a submerged speed of 7.4 knots (13.7 km/h; 8.5 mph). When submerged, she could operate for 52 nautical miles (96 km; 60 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 10,420 nautical miles (19,300 km; 11,990 mi) at 7 knots (13 km/h; 8.1 mph). UC-71 was fitted with six 100 centimetres (39 in) mine tubes, eighteen UC 200 mines, three 50 centimetres (20 in) torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8 cm (3.5 in) Uk L/30 deck gun. Her complement was twenty-six crew members.

## Summary of raiding history

| Date | Name | Nationality | Tonnage | Fate |
| 30 March 1917 | Edernian | United Kingdom | 3,588 | Damaged |
| 30 March 1917 | Saint Louis III | French Navy | 97 | Sunk |
| 30 March 1917 | Sarcelle | France | 49 | Sunk |
| 31 March 1917 | Primrose | United Kingdom | 113 | Sunk |
| 3 April 1917 | Ellen James | United Kingdom | 165 | Sunk |
| 4 April 1917 | Pensiero | Kingdom of Italy | 2,632 | Sunk |
| 5 April 1917 | Gower Coast | United Kingdom | 804 | Sunk |
| 5 April 1917 | San Fulgencio | Spain | 1,558 | Sunk |
| 7 April 1917 | Caminha | Portugal | 2,763 | Sunk |
| 9 April 1917 | Themistoclis | Greece | 1,895 | Sunk |
| 9 April 1917 | Valhall | Norway | 750 | Sunk |
| 10 April 1917 | Ranvik | Norway | 5,848 | Sunk |
| 12 April 1917 | Edelweiss | France | 192 | Sunk |
| 18 April 1917 | Heim | Norway | 1,669 | Sunk |
| 23 April 1917 | Cenobic | Belgium | 16 | Sunk |
| 2 May 1917 | Westland | Netherlands | 108 | Sunk |
| 5 May 1917 | Simon | Netherlands | 150 | Sunk |
| 15 May 1917 | Boreas | Netherlands | 192 | Sunk |
| 16 May 1917 | Hendrika Johana | Netherlands | 134 | Sunk |
| 17 May 1917 | Jakoba | Netherlands | 107 | Sunk |
| 17 May 1917 | Mercurius | Netherlands | 80 | Sunk |
| 18 May 1917 | Annetta | Netherlands | 177 | Sunk |
| 14 June 1917 | Wega | United Kingdom | 839 | Sunk |
| 15 June 1917 | Wapello | United Kingdom | 5,576 | Sunk |
| 26 June 1917 | Normandy | French Navy | 543 | Damaged |
| 28 June 1917 | Marne | France | 4,019 | Sunk |
| 29 June 1917 | Driskos | Greece | 2,833 | Sunk |
| 3 July 1917 | Orleans | United States | 2,853 | Sunk |
| 4 July 1917 | Snetoppen | Norway | 2,349 | Sunk |
| 6 July 1917 | Løvstakken | Norway | 3,105 | Sunk |
| 6 July 1917 | Victoria 2 | Norway | 2,798 | Sunk |
| 8 July 1917 | Vendee | United Kingdom | 1,295 | Sunk |
| 3 August 1917 | Aube | United Kingdom | 1,837 | Sunk |
| 4 August 1917 | Afrique | France | 2,457 | Damaged |
| 4 August 1917 | Cairnstrath | United Kingdom | 2,128 | Sunk |
| 7 August 1917 | Port Curtis | United Kingdom | 4,710 | Sunk |
| 8 August 1917 | HMS Dunraven | Royal Navy | 3,117 | Sunk |
| 6 September 1917 | Elisabethville | Belgium | 7,017 | Sunk |
| 7 September 1917 | Mont de Piete | France | 38 | Sunk |
| 7 September 1917 | Kleber | France | 277 | Damaged |
| 8 September 1917 | Setubal | Norway | 1,201 | Sunk |
| 9 September 1917 | HMS Myosotis | Royal Navy | 1,250 | Damaged |
| 10 September 1917 | Vikholmen | Norway | 494 | Sunk |
| 22 September 1917 | Matti | Norway | 2,139 | Damaged |
| 22 September 1917 | Trongate | United Kingdom | 2,553 | Sunk |
| 23 September 1917 | Hornsund | United Kingdom | 3,646 | Sunk |
| 24 September 1917 | Leka | Norway | 1,845 | Sunk |
| 31 October 1917 | Estrellano | United Kingdom | 1,161 | Sunk |
| 5 November 1917 | USS Alcedo | United States Navy | 983 | Sunk |
| 16 November 1917 | Naalso | French Navy | 135 | Sunk |
| 6 December 1917 | HMT Apley | Royal Navy | 222 | Sunk |
| 6 December 1917 | Wyndhurst | United Kingdom | 570 | Sunk |
| 6 December 1917 | Braeside | United Kingdom | 569 | Sunk |
| 24 December 1917 | Luciston | United Kingdom | 2,877 | Sunk |
| 25 December 1917 | Espagne | Belgium | 1,463 | Sunk |
| 25 December 1917 | Hyacinthus | United Kingdom | 5,756 | Damaged |
| 27 December 1917 | P. L. M. 4 | France | 2,640 | Sunk |
| 28 December 1917 | Fallodon | United Kingdom | 3,012 | Sunk |
| 28 December 1917 | HMD Piscatorial II | Royal Navy | 93 | Sunk |
| 29 December 1917 | HMT Sapper | Royal Navy | 276 | Sunk |
| 18 January 1918 | HMT Gambri | Royal Navy | 274 | Sunk |
| 20 January 1918 | Harmonides | United Kingdom | 3,521 | Damaged |
| 23 January 1918 | Aalesund | Norway | 414 | Sunk |
| 14 February 1918 | Atlas | United Kingdom | 3,090 | Sunk |
| 19 February 1918 | Athenic | United Kingdom | 4,078 | Damaged |
| 19 February 1918 | Commonwealth | United Kingdom | 3,353 | Sunk |
| 8 March 1918 | Saba | United Kingdom | 4,257 | Damaged |
| 12 March 1918 | Clarissa Radcliffe | United Kingdom | 5,754 | Damaged |
| 12 March 1918 | Savan | United Kingdom | 4,264 | Damaged |
| 13 March 1918 | Londonier | Belgium | 1,870 | Sunk |
| 14 March 1918 | HMT Agate | Royal Navy | 248 | Sunk |
| 14 March 1918 | Comrie Castle | United Kingdom | 5,173 | Damaged |
| 7 April 1918 | Highland Brigade | United Kingdom | 5,669 | Sunk |
| 12 April 1918 | Luis | United Kingdom | 4,284 | Sunk |
| 10 May 1918 | Amplegarth | United Kingdom | 3,707 | Sunk |
| 15 May 1918 | Pennyworth | United Kingdom | 5,388 | Damaged |
| 20 May 1918 | Manchester Importer | United Kingdom | 4,028 | Damaged |
| 26 June 1918 | Raranga | United Kingdom | 10,040 | Damaged |
| 31 July 1918 | HMD City of Liverpool | Royal Navy | 88 | Sunk |
| 4 August 1918 | Waipara | United Kingdom | 6,994 | Damaged |
| 5 August 1918 | Polescar | United Kingdom | 5,832 | Damaged |