SM U-125



SM U-125 was one of the 329 submarines serving in the Imperial German Navy in World War I. U-125 was engaged in the naval warfare and took part in the First Battle of the Atlantic.

Design
Type UE II submarines were preceded by the shorter Type UE I submarines. U-125 had a displacement of 1163 t when at the surface and 1468 t while submerged. She had a total length of 82 m, a beam of 7.42 m, a height of 10.16 m, and a draught of 4.22 m. The submarine was powered by two 2400 PS engines for use while surfaced, and two 1235 PS engines for use while submerged. She had two shafts and two 1.61 m propellers. She was capable of operating at depths of up to 75 m.

The submarine had a maximum surface speed of 14.7 kn and a maximum submerged speed of 7.2 kn. When submerged, she could operate for 35 nmi at 4.5 kn; when surfaced, she could travel 11470 nmi at 8 kn. U-125 was fitted with four 50 cm torpedo tubes (fitted at its bow), twelve torpedoes, two 100 cm mine chutes (fitted at its stern), forty-two mines, one 15 cm SK L/45 deck gun, and 494 rounds. She had a complement of forty (thirty-six crew members and four officers).

Post-war
U-125 was surrendered to Japan on 26 November 1918 and was renamed O-1 in 1920 or 1921. She was dismantled at the Yokosuka Naval Arsenal between January and March 1921. Between March 1924 and January 1925, she was used as a floating jetty at the Kure KSubmarine School. In 1925, she was rebuilt at Yokosuka as testbed for submarine salvage operations carried out by the submarine tender JAPANESE BATTLESHIP Asahi. On 19 August 1931, the formerO-1 was recommissioned as Auxiliary Vessel No. 2900 and used as such until 1935.