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 (1907), 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 t when at the surface and 998 t while submerged. She had a total length of 65.80 m, a pressure hull length of 50.07 m, a beam of 6.20 m, a height of 9.35 m, and a draught of 3.88 m. The submarine was powered by two 2400 PS engines for use while surfaced, and two 1200 PS engines for use while submerged. She had two propeller shafts. She was capable of operating at depths of up to 50 m.

The submarine had a maximum surface speed of 15.6 kn and a maximum submerged speed of 8.6 kn. When submerged, she could operate for 56 nmi at 5 kn; when surfaced, she could travel 11380 nmi at 8 kn. U-90 was fitted with four 50 cm torpedo tubes (two at the bow and two at the stern), ten to twelve torpedoes, and one 10.5 cm deck gun. She had a complement of thirty-six (thirty-two crew members and four officers).