SM U - 16 ( Austria - Hungary ) SM " U - 16 or U - XVI " was a or U - boat of the Austro - Hungarian Navy ( ) during World War I . " U - 16 " was constructed in Germany and shipped by rail to Pula where she was assembled and completed in September 1915 . She was commissioned in October 1915 . For most of her career , " U - 16 " operated in the Adriatic out of Kotor patrolling off the Albanian coast . The U - boat sank one small sailing ship in November and seized another in December . " U - 16 " carried Field Marshal Svetozar Borojević of the Austro - Hungarian Army as an observer while performing diving tests after engine repairs in January 1916 . A water leak in March flooded " U - 16 " s batteries and put the U - boat out of action for about six weeks of repairs . While operating off Vlorë in mid - October 1916 , " U - 16 " sank an Italian destroyer acting as a convoy escort . " U - 16 " was sunk in the ensuing action , but sources are not clear on the exact cause of her sinking . In all " U - 16 " sank three ships with a combined tonnage of 711 . She was the only " U - 10 " - class submarine sunk during the war . Design and construction . " U - 16 " was a small , coastal submarine that displaced surfaced and submerged . She featured a single shaft , a single Daimler diesel engine for surface running , and a single electric motor for submerged travel . " U - 16 " 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 - 16 " was equipped with two torpedo tubes located in the front and carried a complement of two torpedoes . Although most members of the class were outfitted with a 37 mm / 23 ( 1 . 5 in ) quick - firing ( QF ) gun to supplement their armament in October 1916 , it is not known whether this upgrade had yet taken place on " U - 16 " by the time of her sinking during that month . " U - 16 " was ordered by the Austro - Hungarian Navy on 1 April 1915 and laid down at AG Weser in Bremen on later in the month . When completed , the submarine was broken down into sections , loaded onto railcars , and shipped on 20 August to the Austro - Hungarian Navy ' s main base at Pula . After completing the eight - day journey , the sections were riveted together . Though there is no specific mention of how long it took for " U - 16 " s sections to be assembled , a sister boat , the German Type UB I submarine " UB - 3 " , shipped to Pula from Germany in mid - April 1915 , was assembled in about two weeks . " U - 16 " was delivered to the Austro - Hungarian Navy on 29 September . Operational history . SM " U - 16 " was commissioned into the Austro - Hungarian Navy on 6 October under the command of " Linienschiffsleutnant " Eugen Hornyák Edler von Horn . Over the next month " U - 16 " patrolled off Rimini and the Po estuary before heading to Kotor . There , " U - 16 " s second commander , " Linienschiffsleutnant " Orest Ritter von Zopa , assumed command on 18 November . The U - boat departed the next day to patrol off Albania . Near Cape Rodoni , von Zopa stopped and boarded " Fiore Albania " , an Albanian sailing ship . Finding nothing amiss , the commander sent " Fiore Albania " on her way . Three days later , von Zopa and " U - 16 " scored their first success , when they sank the Italian sailing vessel " Unione " in the Gulf of Drin . Later the same day , a torpedo attack on two cargo ships in the harbor at Shëngjin netted no results . With her supply of torpedoes expended , " U - 16 " returned to Kotor on 24 November . " U - 16 " set out on her next patrol on 3 December , but had to return to fix a broken gyrocompass , and was underway for Albania the next day . On 5 December , the sailboat " Xephanie " was stopped , searched , and allowed to proceed . Near the same location , " U - 16 " next encountered " Fione Albania " again . When stopped this time , the 62 - ton ship had Montenegrin soldiers , weapons , and ammunition aboard . The vessel was seized as a prize and taken back to Kotor . " U - 16 " attempted two more Albanian patrols at the end of December . The first , departing Kotor on 19 December , was cut short by severe weather that forced the submarine back to port . The next attempt , on 25 December , ended when " U - 16 " suffered engine problems . " U - 16 " sailed for Pula on 27 December for more extensive engine repairs at the naval base there . " U - 16 " s repairs were complete by 9 January 1916 when the submarine departed Pula for diving tests with Field Marshal Svetozar Borojević of the Austro - Hungarian Army on board as an observer . With the tests apparently successful , " U - 16 " returned to Kotor on 18 January to resume Albanian patrols . Off Durrës on 4 February , von Zopa and " U - 16 " launched a torpedo attack on the steamer " Assyria " being escorted by the Italian destroyers and . The torpedo ' s aim was true , but it failed to detonate when it hit the ship . A few days later , a British " Falmouth " - class cruiser attacked the U - boat . On 11 March , a valve on " U - 16 " leaked and water flooded into the boat , inundating the batteries , which released chlorine gas . The U - boat made it back to Kotor and underwent repairs that kept the boat out of action until the end of April . From late April to early September , " U - 16 " patrolled the Adriatic between Vlorë , Brindisi , and the Straits of Otranto . Twice during this time " U - 16 " attacked French destroyers , but missed on both attempts . In mid June , von Zopa launched torpedoes against a cargo ship without result . " U - 16 " put in at Kotor on 3 September for a general overhaul that lasted for about a month . When the repairs were complete , " U - 16 " set out for another Albanian patrol on 9 October . The submarine made a detour to Djenovic on 11 October to replace another faulty gyrocompass , but quickly resumed her journey to the Vlorë area . After discovering an Italian convoy on 17 October , von Zopa torpedoed and sank one of the convoy escorts , the . In the ensuing action , " U - 16 " was sunk , but sources disagree on the exact manner . " Conway ' s All the World ' s Fighting Ships , 1906 – 1921 " reports that the Italian steamer , one of the convoyed ships , rammed and damaged " U - 16 " , causing " U - 16 " s crew to scuttle their ship due to the severity of the damage . Uboat . net ' s " U - Boat War in World War I " reports that " Nembo " herself rammed " U - 16 " before going down , while Robert Grant and Gordon Smith give another possible fate for " U - 16 " : that " Nembo " s depth charges detonated and sank the submarine while " Nembo " was sinking . Smith reports that 11 men aboard " U - 16 " , including her commanding officer von Zopa , lost their lives in the sinking , and that two survivors were picked up . " U - 16 " was the only boat of her class to be sunk during the war . Ships sunk or damaged . < nowiki > * < / nowiki > captured as a prize