# SM UC-70

SM UC-70 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 7 August 1916. She was commissioned into the German Imperial Navy on 20 November 1916 as SM UC-70. In ten patrols UC-70 was credited with sinking 33 ships, either by torpedo or by mines laid. On 28 August 1918, UC-70 was spotted lying submerged on the sea bottom and attacked by a Blackburn Kangaroo patrol aircraft of No. 246 Squadron RAF and then was then sunk by depth charges from the British destroyer HMS Ouse. The wreck is a Protected Wreck managed by Historic England.

## Design

A Type UC II submarine, UC-70 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-70 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 |
| 14 February 1917 | Marthe Yvonne | France | 30 | Sunk |
| 16 March 1917 | Cordouan | France | 28 | Sunk |
| 16 March 1917 | Margaret VI | French Navy | 852 | Damaged |
| 17 March 1917 | Alcide Marie | France | 26 | Sunk |
| 17 March 1917 | Camille Emile | France | 20 | Sunk |
| 17 March 1917 | Dieu Te Garde | France | 30 | Sunk |
| 17 March 1917 | Juliette | France | 29 | Sunk |
| 17 March 1917 | Louis XIV | France | 44 | Sunk |
| 17 March 1917 | Notre Dame Du Perpetuel Secours | France | 29 | Sunk |
| 17 March 1917 | Nozal | France | 34 | Sunk |
| 17 March 1917 | Renee Islander | France | 25 | Sunk |
| 17 March 1917 | Rupella | France | 38 | Sunk |
| 17 March 1917 | Tasso | United Kingdom | 1,859 | Sunk |
| 18 March 1917 | Madone | France | 31 | Sunk |
| 18 March 1917 | Entente Cordiale | France | 22 | Sunk |
| 18 March 1917 | Felicite Albert | France | 32 | Sunk |
| 18 March 1917 | Hyacinthe Yvonne | France | 43 | Sunk |
| 19 March 1917 | Bergsli | Norway | 2,133 | Sunk |
| 19 March 1917 | Michel | France | 1,773 | Sunk |
| 24 March 1917 | Tapir | France | 200 | Sunk |
| 16 April 1917 | Eduard | United Kingdom | 476 | Sunk |
| 17 April 1917 | Nirvana | United Kingdom | 6,021 | Damaged |
| 30 April 1917 | Eden | Norway | 1,304 | Sunk |
| 7 May 1917 | Lowmount | United Kingdom | 2,070 | Sunk |
| 18 May 1917 | C.E.C.G. | United Kingdom | 47 | Sunk |
| 18 May 1917 | Dromore | United Kingdom | 268 | Sunk |
| 23 May 1917 | Begona N°3 | Spain | 2,699 | Sunk |
| 27 May 1917 | General De Boisdeffre | France | 2,195 | Sunk |
| 28 May 1917 | Ancona | United Kingdom | 1,168 | Sunk |
| 27 May 1918 | Wayside Flower | United Kingdom | 21 | Sunk |
| 28 May 1918 | Coronation | United Kingdom | 19 | Sunk |
| 4 June 1918 | Cento | United Kingdom | 3,708 | Damaged |
| 9 July 1918 | Frederika | Netherlands | 91 | Sunk |
| 17 July 1918 | Elin | Norway | 139 | Damaged |
| 21 July 1918 | Genesee | United Kingdom | 2,830 | Damaged |
| 21 July 1918 | Mongolian | United Kingdom | 4,892 | Sunk |
| 23 July 1918 | Boorara | Australia | 6,570 | Damaged |
| 24 July 1918 | Kilkis | Greece | 4,302 | Sunk |
| 26 July 1918 | Ango | France | 7,393 | Damaged |
| 28 August 1918 | Giralda | United Kingdom | 1,100 | Sunk |

## Loss

UC-70 was depth charged and sunk off Whitby, Yorkshire on 28 August 1918 with the loss of all 31 crew. The wreck was given protected status by Historic England in 2017.