SM U - 2 ( Austria - Hungary ) SM " U - 2 or U - II " was a " U - 1 " - class submarine or U - boat built for and operated by the Austro - Hungarian Navy ( ) . " U - 2 " was designed by American Simon Lake ' s Lake Torpedo Boat Company and built at the navy yard in Pola . She was one of two Lake - designed submarines purchased as part of a competitive evaluation of three foreign submarine designs . " U - 2 " was launched in April 1909 and was long and displaced almost surfaced and just under when submerged . The Austro - Hungarian Navy conducted trials for " U - 2 " through 1910 . The U - boat was originally powered by two gasoline engines for surface running , and two electric motors when submerged , but during her evaluation period , the gasoline engines were found to be incapable of reaching the contracted speed . " U - 2 " was commissioned in June 1911 and served as a training boat for the Austro - Hungarian Navy through 1914 . At the beginning of World War I , " U - 2 " was not operational because she was in drydock awaiting replacement diesel engines . With her new engines and a new conning tower installed by June 1915 , " U - 2 " conducted reconnaissance cruises out of Trieste but was declared obsolete in early 1918 . " U - 2 " remained in service as a training boat at the submarine base on Brioni , but was at Pola at the end of the war . She was ceded to Italy as a war reparation in 1920 and scrapped at Pola . " U - 2 " did not sink any ships during the war . Design and construction . " U - 2 " was built as part of a plan by the Austro - Hungarian Navy to competitively evaluate foreign submarine designs from Simon Lake , Germaniawerft , and John Philip Holland . The Austro - Hungarian Navy ordered plans for " U - 2 " ( and sister ship " U - 1 " ) in 1906 from the Lake Torpedo Boat Company of Bridgeport , Connecticut . " U - 2 " was built at the Pola Navy Yard and was launched on 3 April 1909 . " U - 2 " had several features typical of Lake ' s designs , including a diving chamber under the bow and two variable pitch propellers . Lake ' s design also called for two retractable wheels that allowed travel over the seabed . The design also placed the diving tank s above the waterline of the single , cylindrical hull , which necessitated a heavy ballast keel for vertical stability . This arrangement required mechanical pumping , a procedure that took 8 minutes . " U - 2 " s propulsion system consisted of two gasoline engines for surface running and two electric motors for running while submerged . The boat was long by abeam and had a draft of . As designed , her displacement was surfaced and submerged . She was outfitted with three torpedo tubes — two in the bow , one in the stern — and could carry up to five torpedoes , but typically carried three . " U - 2 " was also armed with a deck gun . Service career . Upon " U - 2 " s completion , the Austro - Hungarian Navy conducted trials of the submarine throughout most of 1910 . " U - 2 " s gasoline engines were never able to meet the speed called for in the contract during the Navy evaluations , and were considered not suitable for wartime use . As a result , the Navy only paid for " U - 2 " s hull and armament , and arranged a lease of the gasoline engines while replacement diesel engines were ordered from the Austrian firm " Maschinenfabrik " Leobersdorf . Despite the engine problems , " U - 2 " and her sister ship had the best performance in diving and steering amongst the U - boats under evaluation by the Navy . " U - 2 " was commissioned into the Austro - Hungarian Navy on 22 June 1911 under the command of " Linienschiffsleutnant " Klemens Ritter von Bézard . " U - 2 " served as a training boat through 1915 , conducting up to ten training cruises per month . At the outbreak of World War I , she was in drydock awaiting the installation of her new diesel engines . To accommodate the new engines , she was lengthened by about . The modifications and new engines lowered her surface displacement to but increased her submerged displacement to . From January to June 1915 , " U - 2 " underwent a refit and received a new conning tower . She was stationed at Trieste in mid July and conducted reconnaissance cruises from that port . On 11 January 1918 , she was declared obsolete , but was retained as a training boat at the submarine base on Brioni . " U - 2 " was at Pola at the war ' s end , and was scrapped after her cession to Italy as a war reparation in 1920 . " U - 2 " did not sink any ships during the war .