SM U - 12 ( Austria - Hungary ) SM " U - 12 or U - XII " was a " U - 5 " - class submarine or U - boat built for and operated by the Austro - Hungarian Navy ( ) before and during the First World War . Introduction . Built on speculation by Whitehead & Co . of Fiume , the submarine was launched as SS - 3 and featured improvements in the electrical and mechanical systems from the design by the American John Philip Holland , to which her older sister boats , and , had been built . " SS - 3 " was laid down in 1909 and launched in March 1911 . The double - hull ed submarine was just over long and displaced between , depending on whether surfaced or submerged . Whitehead ' s tried selling " SS - 3 " to several different navies , but she was finally bought by the Austro - Hungarian Navy after the outbreak of World War I , despite having been rejected by them twice before . She was commissioned as " U - 12 " in August 1914 . The submarine sank only one ship , a Greek cargo ship in May 1915 , but she had earlier captured six Montenegrin sailing vessels as prizes in March . " U - 12 " also damaged , but did not sink , the French battleship " Jean Bart " in December 1914 . While searching for targets in the vicinity of Venice in August 1915 , " U - 12 " struck a mine that blew her stern off , and sank with all hands , becoming the first Austro - Hungarian submarine sunk in the war . Her wreck was salvaged the next year by the Italians , who interred " U - 12 " s crewmen in a Venetian cemetery . Design and construction . " SS - 3 " was built on speculation by Whitehead & Co . of Fiume . Her design was based on the John Philip Holland design licensed by Whitehead for and , two submarines ordered by the Austro - Hungarian Navy and built 1907 – 1910 , and featured improvements in the mechanical and electrical systems . " SS - 3 " was laid down in 1909 and launched at Fiume on 14 March 1911 . " SS - 3 " s featured a single - hull with a tear - drop shaped body that bore a strong resemblance to modern nuclear submarines . She was long by abeam and had a draft of . She displaced surfaced , and submerged . Her two bow torpedo tubes featured unique , cloverleaf - shaped design hatch es that rotated on a central axis , and the boat was designed to carry up to four torpedoes . According to one source , " SS - 3 " was initially propelled by a pair of electric motors for surface running , but had them replaced with twin 6 - cylinder gasoline engines of each when they proved disappointing during trials . It is not specifically reported for " U - 12 " , but the other " U - 5 " - class boats both suffered from inadequate ventilation , which resulted in frequent intoxication of the crew from the engine exhaust . " SS - 3 " s underwater propulsion was by two electric motors that totaled . Career . After " SS - 3 " s March 1911 launch , Whitehead ' s tried to sell " SS - 3 " to the Austro - Hungarian Navy , but because the evaluation of the first two " U - 5 " - class boats was still underway , they declined to purchase . Over the next three years Whitehead ' s attempted to sell the boat to the navies of Peru , Portugal , the Netherlands , Brazil , and Bulgaria , before the Austro - Hungarian Navy rejected an offer for the second time . With the outbreak of war , however , the Austro - Hungarian Navy purchased the unsold submarine to quickly bolster its fleet . Although provisionally assigned the designation " U - 7 " , the submarine was commissioned as SM " U - 12 " on 21 August 1914 , with " Linienschiffsleutnant " Egon Lerch in command . " U - 12 " s activities over the early part of the war are not reported , but the boat ' s armament was augmented by a 3 . 7 cm / 23 ( 1 . 5 in ) quick - firing ( QF ) deck gun in November 1914 . Sister boat " U - 5 " had her first radio receiver installed at the same time her deck gun was added , but it is not reported whether " U - 12 " did as well . On 21 December 1914 , Lerch and " U - 12 " chanced upon the French dreadnought " Jean Bart " in the Straits of Otranto steaming at a leisurely and unprotected by escort ships . " U - 12 " hit French Admiral Lapeyrère ' s flagship with a single torpedo in the bow , destroying the battleship ' s wine storeroom but sparing her forward magazine . " Jean Bart " s watertight compartments saved the ship , which made her way to Malta to undergo repairs at the British dockyards there . " U - 12 " survived an attack from an unknown French on 27 February 1915 . " U - 12 " s next success was the capture of two Montenegrin schooners on 22 March 1916 , " Fiore Di Dulcigno " and " Hilussie " . Nine days later the U - boat captured another four Montenegrin boats , " Buona Forte " , " Fiore I " , " Hailie " , and " Indaverdi " . On 29 May , she sank the Greek steamer " Virginia " , which was the only ship reported sunk by " U - 12 " . In June , " U - 12 " underwent a refit that added an additional two torpedo tubes on her forward casing . In early August , Lerch and " U - 12 " set out from Pola for Venice to look for enemy ships to sink . On 6 August , the Italian destroyer " Rosolino Pilo " rammed " U - 12 " , probably by chance , at about 05 : 00 in the Lido inlet of the Venetian Lagoon . Two days later , when Italian workers were dredging to try to determine the object " Rosolino Pilo " had hit , they heard a heavy explosion . When divers went down in the area , they discovered the wreck of " U - 12 " with her stern blown off . " U - 12 " s entire complement of 17 men was lost when she went down . " U - 12 " was the first Austro - Hungarian submarine sunk during the war . In late 1916 , the Italians salvaged the hulk of " U - 12 " and transported it to Venice . The bodies of " U - 12 " s crew were interred at the San Michele cemetery in Venice , and " U - 12 " s hulk , of no salvage value , was scrapped at the Venice naval arsenal . In her military service , " U - 12 " sank one ship of , damaged one warship ( ) , and captured six ships as prizes .