SM U - 29 ( Austria - Hungary ) SM " U - 29 or U - XXIX " was a " U - 27 " class U - boat or submarine for the Austro - Hungarian Navy . " U - 29 " , built by the Hungarian firm of Ganz Danubius at Fiume , was launched in October 1916 and commissioned in January 1917 . " U - 29 " had a single hull and was just over in length . She displaced nearly when surfaced and over when submerged . Her two diesel engines moved her at up to on the surface , while her twin electric motors propelled her at up to while underwater . She was armed with two bow torpedo tube s and could carry a load of up to four torpedoes . She was also equipped with a deck gun and a machine gun . During her service career , " U - 29 " sank three ships and damaged two others , sending a combined tonnage of to the bottom . " U - 29 " was at Fiume at war ' s end and was surrendered at Venice in March 1919 . She was granted to France as war reparation in 1920 , but foundered while under tow to Bizerta for scrapping . Design and construction . Austria - Hungary ' s U - boat fleet was largely obsolete at the outbreak of World War I . The Austro - Hungarian Navy satisfied its most urgent needs by purchasing five Type UB I submarines that comprised the from Germany , by raising and recommissioning the sunken French submarine " Curie " as , and by building four submarines of the that were based on the 1911 Danish " Havmanden " class . After these steps alleviated their most urgent needs , the Austro - Hungarian Navy selected the German Type UB II design for its newest submarines in mid 1915 . The Germans were reluctant to allocate any of their wartime resources to Austro - Hungarian construction , but were willing to sell plans for up to six of the UB II boats to be constructed under license in Austria - Hungary . The Navy agreed to the proposal and purchased the plans from AG Weser of Bremen . " U - 29 " displaced surfaced and submerged . She had a single hull with saddle tank s , and was long with a beam of and a draft of . For propulsion , she had two shafts , twin diesel engines of for surface running , and twin electric motors of for submerged travel . She was capable of while surfaced and while submerged . Although there is no specific notation of a range for " U - 29 " in " Conway ' s All the World ' s Fighting Ships , 1906 – 1921 " , the German UB II boats , upon which the " U - 27 " class was based , had a range of over at surfaced , and at submerged . " U - 27 " - class boats were designed for a crew of 23 – 24 . " U - 29 " was armed with two bow torpedo tube s and could carry a complement of four torpedoes . She was also equipped with a 75 mm / 26 ( 3 . 0 in ) deck gun and an machine gun . After intricate political negotiations to allocate production of the class between Austrian and Hungarian firms , " U - 27 " was ordered from Ganz Danubius on 12 October 1915 . She was laid down on 3 March 1916 at Fiume and launched on 21 October . Service career . " U - 29 " underwent diving trials at Fiume and then made her way to Pola on 29 November 1916 . There , on 21 January 1917 , SM " U - 29 " was commissioned into the Austro - Hungarian Navy under the command of " Linenschiffleutnant " Leo Prásil . Prásil , a 29 - year - old native of Pola , had previously served as commander of . " U - 29 " departed on her first patrol on 23 January , destined for duty in the Mediterranean . The next day , however , the U - boat encountered a severe storm near Lussin that damaged her . Prásil steered the boat into the harbor at Brgulje to wait out the storm . Departing Brgulje on the 25th to resume her journey to the Mediterranean , the submarine developed a leak when performing a test dive . " U - 29 " headed back to Pula for repairs , which lasted until 30 January . On 5 February the U - boat set out for Cattaro , which she reached after three days journey . Prásil took " U - 29 " out of Cattaro on 17 February to begin the delayed patrol in the Mediterranean , but on the 20th encountered another severe storm . Suffering no damage in the tempest , the boat continued on . On 24 February , she had an at - sea rendezvous with . On 1 March the U - boat ' s gyrocompass broke down , necessitating a return to port . Two days later , as she neared Cattaro , " U - 29 " encountered yet another storm , this one again damaging the ship . The beleaguered U - boat headed back to the base at Pula for more repairs , and remained there until early April . On 4 April , " U - 29 " set out from Pula , touched at Cattaro , and continued on into the Mediterranean for her second patrol there . While from Cape Matapan , Prásil torpedoed and sank the steamer " Dalton " , traveling in ballast . " U - 29 " took the master of the 3 , 486 - ton British ship captive ; three other men lost their lives in the attack . Five days later and some away , " U - 29 " torpedoed , a British India Line passenger steamer of . The ship , en route from Calcutta to London with a general cargo , was finished off by " U - 29 " s deck gun . As with " Dalton " , " Mashobra " s master was taken prisoner . Eight persons died in the attack . " U - 29 " s gyrocompass broke down again on 17 April , once again forcing the boat to return for repairs . " U - 29 " s second Mediterranean tour ended when Prásil docked the boat at Cattaro on 19 April . " U - 29 " s third Mediterranean deployment began on 8 May when she departed Cattaro . After eleven days at sea , Prásil torpedoed the British cargo ship " Mordenwood " from Cape Matapan . " U - 29 " took the 3 , 125 - ton ship ' s master captive . Two sources disagree on the number of casualties when " Mordenwood " went down , but place the number at either 21 or 31 . Escorting destroyers launched a depth charge attack on " U - 29 " but did not succeed in damaging the U - boat . Two days later , " U - 29 " launched a torpedo attack on the British steamer " Marie Suzanne " but did not sink the ship . " U - 29 " arrived at Cattaro on 25 May . After a brief time in port , " U - 29 " set out for the Mediterranean again on 17 June . One day out , the U - boat came under attack from an airplane out of Valona , compelling " U - 29 " to crash dive ; none of the three bombs dropped by the aircraft hit their mark . " U - 29 " s patrol ended without success when she docked at Cattaro on 6 July . After a return to Pola on 12 July , the U - boat underwent extensive repairs that kept her out of action for the next nine months . On 16 March 1918 , the newly refitted boat sailed from Pola to Cattaro , departing that port for another Mediterranean tour on 25 March . Near Valona the next day , an Italian destroyer attempted to ram " U - 29 " , scraping one of her propellers against " U - 29 " s conning tower . The damage done was slight and " U - 29 " continued on into the Mediterranean , weathering a storm in the Ionian Sea on the 27th . On 4 April , " U - 29 " launched a torpedo attack on what was thought to be a cargo ship . In fact , it was the British protected cruiser which had been hit . " Edgar " was damaged but did not sink ; she suffered no casualties in the attack . The following day Prásil attempted to torpedo a ship in a convoy but missed and was exposed to a depth charge attack by the convoy ' s escorts . The U - boat ended the patrol with no further successes . In June , the Austro - Hungarian Navy planned an assault on the Otranto Barrage , similar to a May 1917 action that evolved into the Battle of Otranto Straits . " U - 29 " was deployed from Cattaro on 9 June in advance of the attack . One of the seven separate groups participating in the attack , the two dreadnoughts and , came under attack from Italian MAS torpedo boats in the early morning hours of 10 June . " Szent István " was hit and sank just after 06 : 00 , and the entire operation was called off . " U - 29 " returned to Cattaro on 12 June . Over the next two months , " U - 29 " operated in the Adriatic out of Cattaro , patrolling off Durazzo and the Albanian coast . While at Cattaro , command of " U - 29 " passed to " Linenschiffleutnant " Friedrich Sterz on 4 September . The 27 - year - old native of Pergine , Tyrolia ( in present - day Italy ) , had previously commanded and , like Prásil , had also served a stint as commander of " U - 10 " . After assuming command of " U - 29 " , Sterz set sail for Durazzo the same day . The U - boat had encounters with MAS torpedo boats on 9 and 12 September . On the latter date , " U - 29 " had to crash dive to avoid a bombing attack from Allied airplanes . None of the seven bombs hit their mark and " U - 29 " returned to Cattaro on 16 September . " Linenschiffleutnant " Robert Dürrial replaced Sterz as commander on 29 September . The Galician Dürrial , like both Stertz and Prásil , had served as the commander of " U - 10 " , but had most recently commanded . A day after assuming command , Dürrial headed for the Albanian coast in " U - 29 " and patrolled off Durazzo . After the Armistice with Bulgaria on 29 September ended Bulgaria ' s participation in the war , Durazzo gained importance to the remaining Central Powers as the main port for supplying their forces fighting in the Balkans . Anticipating this , the Allies put together a force to bombard Durazzo . While the second echelon of the attacking force got into position to bombard the town , " U - 29 " and sister boat maneuvered to attack . While " U - 31 " was able to hit and damage the British cruiser , " U - 29 " was blocked by screening ships and herself attacked . The Allied escorts subjected " U - 29 " to a heavy depth charge attack . " U - 29 " was able to make her way back to Cattaro on 8 October . Over the next three weeks , " U - 29 " patrolled between Cattaro and Antivari , Montenegro . After her arrival back at Cattaro on 1 November , " U - 29 " was moored between the coastal battleship and . There she remained until she was awarded to France as a war reparation in 1920 . " U - 29 " was towed , along with sister boats " U - 31 " and , from Cattaro for Bizerta for scrapping , but foundered on the way . In total , " U - 29 " sank three ships with a combined tonnage of 14 , 784 , and damaged one warship . Ships sunk or damaged . < nowiki > * < / nowiki > damaged but not sunk Notes . 3 . Josef Guenther Lettenmaier , who served on U 29 as " Maschinenquartiermeister " , roughly equivalent to Machinist Mate 2nd Class , documented his experiences in the Austro - Hungarian Navy and aboard U 29 as historical fiction in " Rot - Weiss - Rot zur See " , published by Tyrolia Verlag , Innsbruck , 1934 . Lettenmaier ' s book is the only published record of the K . u . k . U - Waffe written by " other ranks " .