SM U - 3 ( Austria - Hungary ) SM " U - 3 or U - III " was the lead boat of the " U - 3 " class of submarine s or U - boat s built for and operated by the Austro - Hungarian Navy ( ) before and during the First World War . The submarine was built as part of a plan to evaluate foreign submarine designs , and was built by Germaniawerft of Kiel , Germany . " U - 3 " was authorized in 1906 , begun in March 1907 , launched in August 1908 , and towed from Kiel to Pola in January 1909 . The double - hull ed submarine was just under long and displaced between , depending on whether surfaced or submerged . The design of the submarine had poor diving qualities and several modifications to " U - 3 " s diving plane s and fins occurred in her first years in the Austro - Hungarian Navy . Her armament , as built , consisted of two bow torpedo tubes with a supply of three torpedoes , but was supplemented with a deck gun in 1915 . The boat was commissioned into the Austro - Hungarian Navy in September 1909 , and served as a training boat — sometimes making as many as ten cruises a month — through the beginning of the First World War in 1914 . At the start of that conflict , she was one of only four operational submarines in the Austro - Hungarian Navy U - boat fleet . Over the first year of the war , " U - 3 " conducted reconnaissance cruises out of Cattaro . On 12 August 1915 , " U - 3 " was damaged after an unsuccessful torpedo attack on an Italian armed merchant cruiser and , after she surfaced the next day , was sunk by a French destroyer . " U - 3 " s commanding officer and 6 men died in the attack ; the 14 survivors were captured . Design and construction . " U - 3 " 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 authorized the construction of " U - 3 " ( and sister ship , " U - 4 " ) in 1906 by Germaniawerft of Kiel , Germany . " U - 3 " was laid down on 12 March 1907 and launched on 20 August 1908 . After completion , she was towed via Gibraltar to Pola , where she arrived on 24 January 1909 . " U - 3 " s design was an improved version of Germaniawerft ' s design for the Imperial German Navy ' s first U - boat , , and featured a double hull with internal saddle tank s . The Germaniawerft engineers refined the design ' s hull shape through extensive model trials . " U - 3 " was long by abeam and had a draft of . She displaced surfaced and submerged . She was armed with two bow torpedo tubes , and was designed to carry up to three torpedoes . Service career . After " U - 3 " s arrival at Pola in January 1909 , she was commissioned into the Austro - Hungarian Navy on 12 September 1909 as SM " U - 3 " . During the evaluation of the " U - 3 " class conducted by the Navy , the class ' poor diving and handling characteristics were noted . To alleviate the diving problems , " U - 3 " s fins were changed in size and shape several times , and eventually , the front diving plane s were removed and a stationary stern flap was affixed to the hull . " U - 3 " served as a training boat between 1910 and 1914 and made as many as ten cruises per month in that capacity . At the beginning of World War I , she was one of only four operational submarines in the Austro - Hungarian Navy . On 22 August 1914 , " U - 3 " began operating reconnaissance cruises out of the naval base at Brioni , but moved a month later to Cattaro . In April 1915 , a quick firing ( QF ) deck gun was added . On 10 August , " U - 3 " departed from Cattaro for what would be her final time for a patrol north of Brindisi . Two days later , while returning to Cattaro from the Straits of Otranto , " U - 3 " launched a torpedo attack on the Italian armed merchant cruiser . The torpedoes missed their mark and , in the ensuing action , " U - 3 " was rammed by " Citta di Catania " , which destroyed the U - boat ' s periscope . When she attempted to surface , she was shelled by the escorting destroyers . She submerged to escape the artillery but was further damaged by a depth charge attack from the French destroyer " Bisson " while resting on the seabed . When " U - 3 " surfaced the following day , she was shelled and sunk by " Bisson " . Fourteen of her crew were saved and captured , but seven died in the attack , including her commander , " Linienschiffsleutnant " Karl Strnad . " U - 3 " had no successes during the war .