SM U - 11 ( Austria - Hungary ) SM " U - 11 or U - XI was a in the Austro - Hungarian Navy ( ) during World War I . She was originally a German Type UB I submarine commissioned into the German Imperial Navy ( ) as SM " UB - 15 . SM " UB - 15 " was constructed in Germany and shipped by rail to Pola , where she was assembled and launched . She was commissioned into the German Imperial Navy in April and sank an Italian submarine in June . The boat was handed over to Austria - Hungary and commissioned as SM " U - 11 " on 14 June . In early 1916 , " U - 11 " fired on a British submarine , but missed . After the end of the war , " U - 11 " was handed over to Italy as a war reparation and scrapped at Pola by 1920 . Design and construction . " U - 11 " was a small coastal submarine that displaced surfaced and submerged . She featured a single shaft , a single Körting diesel engine for surface running , and a single electric motor for submerged travel . " U - 11 " was capable of up to while surfaced and while submerged at a diving depth of up to . She was designed for a crew of 17 officers and men . " U - 11 " was equipped with two torpedo tubes located in the front and carried a complement of two torpedoes . German Type UB I submarines were additionally equipped with a machine gun , but it is not clear from sources if " U - 11 " a former German boatwas fitted with one , or if it was , retained it in Austro - Hungarian service . In October 1916 , " U - 11 " s armament was supplemented with a 66 mm / 18 ( 2 . 6 in ) gun . " UB - 15 " was laid down on 9 November 1914 at AG Weser in Bremen . The submarine was shipped by rail in sections to Pola , where the sections were riveted together . There is no known surviving record of how long it took for UB - 15 ' s sections to be assembled . However , a similar ship ( " UB - 3 " ) was built in two weeks . Operational history . SM " UB - 15 " was commissioned into the German Imperial Navy under the command of " Oberleutnant zur See " Heino von Heimburg on 11 April . An Austro - Hungarian Navy officer was assigned to the boat for piloting and training purposes . On 10 June , " UB - 15 " sank the Italian submarine " Medusa " for a loss of 245 tons off Porto di Piave Vecchia in the Northern Adriatic . Like all Type UB I and U - 10 class submarines , " UB - 15 " was equipped with compensating tanks designed to flood and offset the loss of one of the C / 06 torpedoes . However , they did not always function correctly ; when firing from periscope depth the boat could broach after firing or , if too much weight was taken on , plunge to the depths . When " UB - 15 " torpedoed and sank " Medusa " , the tank failed to properly compensate , forcing all of the crewmen to run to the stern to offset the trim imbalance and prevent the ship from sinking . On 14 June , " UB - 15 " was handed over to the Austro - Hungarian Navy and commissioned as " U - 11 " under the command of " Linienschiffsleutnant " Lüdwig Eberhardt . " U - 11 " retained its German crew until 18 June 1916 , when they were replaced by an all Austro - Hungarian one . In early 1916 , " U - 11 " unsuccessfully attacked the British submarine in the Gulf of Fiume . " U - 11 " sank no ships in her Austro - Hungarian service , and was handed over to Italy as a war reparation and scrapped at Pola by 1920 .