SM U - 22 ( Austria - Hungary ) SM " U - 22 or U - XXII " was a or U - boat built for and operated by the Austro - Hungarian Navy ( ) during the First World War . The design for " U - 22 " 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 - 22 " was just over long and was armed with two bow torpedo tubes , a deck gun , and a machine gun . The submarine was laid down in mid 1915 and launched in January 1917 . The still unfinished U - boat sank in the harbor at Fiume in June but was raised , repaired , and relaunched in October . After her commissioning in November , " U - 22 " patrolled off the Po River estuary and , later , in the northern Adriatic out of Trieste . After undergoing months of repairs for her failed electric motor in mid 1918 , " U - 22 " returned to duty and patrolled off the Montenegrin coast out of Cattaro in August . At Cattaro at the end of World War I , " U - 22 " was ceded to France as a war reparation and scrapped in 1920 . " U - 22 " 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 - 22 " and her three sister boats on 27 March 1915 . " U - 22 " was one of two boats of the class to be built at the Hungarian yard in Fiume . Due to demands by the Hungarian government , subcontracts for the class were divided between Hungarian and Austrian firms , and this politically expedient solution worsened technical problems with the design , resulting in numerous modifications and delays for the class in general . " U - 22 " was an ocean - going submarine that displaced surfaced and submerged and was designed for a complement of 18 . She was long with a beam of and a draft of . For propulsion , she featured a single shaft , a single diesel engine for surface running , and a single electric motor for submerged travel . She was capable of while surfaced and while submerged . Although there is no specific notation of a range for " U - 22 " , the " Havmanden " class , upon which the " U - 20 " class was based , had a range of at , surfaced , and at submerged . " U - 22 " was armed with two torpedo tubes located in the front and carried a complement of two torpedoes . She was also equipped with a 66 mm / 26 ( 2 . 6 in ) deck gun and an machine gun . " U - 22 " was laid down at Fiume in mid 1915 and launched on 27 January 1917 , the last of the four " U - 20 " - class boats to be launched . On 10 June , while not yet complete , the U - boat sank in the harbor at Fiume . Raised from her resting point at a depth of the following day , " U - 22 " underwent four months of repairs . She was launched again on 6 October . Service career . On 18 November 1917 the U - boat sailed for Pola , where she was commissioned as SM " U - 22 " on 23 November under the command of " Linienschiffsleutnant " Josef Holub . The 31 - year - old Galician had been assigned to " U - 22 " in February and had been in charge of sister boat from June 1916 until his assignment to " U - 22 " . Holub led " U - 22 " out on her first patrol when they departed Pola on 5 December for duty off the Po estuary . After returning to Pola on 10 December , Holub led " U - 22 " on another Po estuary tour from 15 to 17 December . On 29 December , Holub was transferred to . His replacement was " Linienschiffsleutnant " Friedrich Sterz . It was the first U - boat command of the 25 - year - old native of Pergine , Tyrolia ( in present - day Italy ) . On 3 January 1918 , Sterz returned " U - 22 " to the Po estuary for a third patrol there . While in the area , an enemy submarine was spotted but no attack could be made because of bad weather ; the same bad weather forced " U - 22 " to put in at Rovigno the following day . Setting out from Rovigno on 5 January , " U - 22 " unsuccessfully attacked an Italian torpedo boat and two steamships . After a return to Rovigno on 6 January , Sterz steered his boat to the submarine base at Brioni . Ten days later , " U - 22 " headed to Trieste , where she conducted patrols in the northern Adriatic . On 5 February , " U - 22 " avoided being hit by seven bombs dropped by an enemy airplane . Departing the northern Adriatic in late April , " U - 22 " was headed for Cattaro when her electric motor failed . After a quick stop at Cattaro , " U - 22 " returned to Pola for three months of repairs . After returning to service in August , " U - 22 " operated out of Catttaro , patrolling off the Montenegrin coast over the next two months . On 17 October , the boat returned to Cattaro , where she remained until the war ' s end . She was ceded to France as a war reparation and scrapped in 1920 . Like all of her sister boats , " U - 22 " had no wartime successes .