# SM U-90

SM U-90 was a Type U-87 U-boat of the Imperial German Navy during World War I. Its commander Walter Remy made regular stops at remote island North Rona for provisions such as fresh mutton. On 15 May 1918, U-90 shelled the Hirta wireless station in St Kilda, Scotland. On 31 May 1918, U-90 torpedoed and sank USS President Lincoln, a former Hamburg America Line steamer that had been seized by the United States for troop transportation. From the U.S. Navy crew that abandoned the sinking vessel, U-90 captured Lieutenant Edouard Izac, eventually taking him to Germany. Izac later escaped German captivity and reported to the US Navy about German submarine movements.
U-90 was surrendered to the Allies at Harwich on 20 November 1918 in accordance with the requirements of the Armistice with Germany, and later laid up at Pembroke. She was to be loaned to Belgium, and was en route there in tow from Pembroke when she foundered off the Isle of Wight on 29 November 1919.

## Design

Type U 87 submarines were preceded by the shorter Type U 81 submarines. U-90 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-90 was fitted with four 50 centimetres (20 in) torpedo tubes (two at the bow and two at the stern), ten to twelve torpedoes, and one 10.5-centimetre (4.1 in) 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 |
| 25 September 1917 | Union Republicaine | France | 44 | Sunk |
| 27 September 1917 | Deux Jeannes | France | 50 | Sunk |
| 27 September 1917 | Liberte | France | 49 | Sunk |
| 27 September 1917 | Peuples Freres | France | 41 | Sunk |
| 30 September 1917 | Drake | United Kingdom | 2,267 | Sunk |
| 30 September 1917 | Heron | United Kingdom | 885 | Sunk |
| 1 October 1917 | Neuilly | France | 2,186 | Sunk |
| 3 October 1917 | Jeannette | France | 226 | Sunk |
| 20 November 1917 | Robert Morris | United Kingdom | 146 | Sunk |
| 21 November 1917 | Aros Castle | United Kingdom | 4,460 | Sunk |
| 22 January 1918 | Corton | United Kingdom | 3,405 | Damaged |
| 22 January 1918 | Victor De Chavarri | Spain | 2,957 | Sunk |
| 24 January 1918 | Charles | United Kingdom | 78 | Sunk |
| 25 January 1918 | Normandy | United Kingdom | 618 | Sunk |
| 26 January 1918 | Union | France | 677 | Sunk |
| 30 January 1918 | Lindeskov | Denmark | 1,254 | Sunk |
| 31 January 1918 | Martin Gust | Russian Empire | 248 | Sunk |
| 1 February 1918 | Arrino | United Kingdom | 4,484 | Sunk |
| 16 March 1918 | Oilfield | United Kingdom | 4,000 | Sunk |
| 28 March 1918 | City of Winchester | United Kingdom | 114 | Sunk |
| 8 April 1918 | Superb | Norway | 489 | Sunk |
| 29 May 1918 | Begum | United Kingdom | 4,646 | Sunk |
| 29 May 1918 | Carlton | United Kingdom | 5,265 | Sunk |
| 31 May 1918 | USS President Lincoln | United States Navy | 18,168 | Sunk |
| 15 August 1918 | USS Montanan | United States Navy | 6,659 | Sunk |
| 15 August 1918 | J. M. J. | France | 54 | Sunk |
| 16 August 1918 | USS West Bridge | United States Navy | 5,189 | Damaged |
| 17 August 1918 | Escrick | United Kingdom | 4,151 | Sunk |
| 17 August 1918 | Joseph Cudahy | United States | 3,302 | Sunk |
| 24 August 1918 | Graciosa | Portugal | 2,276 | Sunk |
| 14 October 1918 | Dundalk | United Kingdom | 794 | Sunk |
| 16 October 1918 | Pentwyn | United Kingdom | 3,587 | Sunk |