German submarine U-23

U-23 may refer to one of the following German submarines:

German submarine U-23

U-23 may refer to one of the following German submarines:

SM U-23 (Austria-Hungary)

SM U-23 or U-XXIII was a U-20-class submarine or U-boat built for and operated by the Austro-Hungarian Navy (German: Kaiserliche und Königliche Kriegsmarine or K.u.K. Kriegsmarine) during the First World War. The design for U-23 was based on submarines of the Royal Danish Navy's Havmanden class (three of which had been built in Austria-Hungary), and was largely obsolete by the beginning of the war.

U-23 was just over 127 feet (39 m) long and was armed with two bow torpedo tubes, a deck gun, and a machine gun. In February 1918, U-23 was sunk with all hands by the Italian torpedo boat Airone while attempting an attack on the Italian transport Memfi. U-23 had no wartime successes.

Design and construction

When it became apparent to the Austro-Hungarian Navy that the First World War would not be a short one, they moved to bolster their U-boat fleet by seizing the plans for the Danish Havmanden class submarines, three of which had been built at Whitehead & Co. in Fiume. Although the Austro-Hungarian Navy was not happy with the design, which was largely obsolete, it was the only design for which plans were available and which could be begun immediately in domestic shipyards. The Austro-Hungarian Navy unenthusiastically placed orders for U-23 and her three sister boats on 27 March 1915.