SM UB - 49 SM " UB - 49 " was a German Type UB III submarine or U - boat in the German Imperial Navy ( ) during World War I . She was commissioned into the German Imperial Navy on 28 June 1917 as SM " UB - 49 " . " UB - 49 " served mainly in the Mediterranean . In the Austro - Hungarian Navy she was listed as SM " U - 80 " . In eight wartime patrols she sank 40 ships totaling and one escort . After the Armistice with Germany " UB - 49 " returned to Kiel via Norway . Handed over to the United Kingdom on 16 January 1919 , she was broken up in Swansea in 1922 . Construction . " UB - 49 " was ordered by the German Imperial Navy on 20 May 1916 . She was built by Blohm & Voss , Hamburg and following just under a year of construction , launched at Hamburg on 6 January 1917 . " UB - 49 " was commissioned later that same year under the command of Kapitänleutnant ( Kptlt . ) Hans - Joachim von Mellenthin . Like all Type UB III submarines , " UB - 49 " carried 10 torpedoes and was armed with an deck gun . " UB - 49 " could carry a crew of up to 34 men and had a cruising range of . " UB - 49 " had a displacement of while surfaced and when submerged . Her engines enabled her to travel at when surfaced and when submerged . Service history . First War Patrol . On 22 August 1917 , " UB - 49 " left Kiel for Cattaro to join the Pola Flotilla passing the Orkney - Shetland barrier four days later . Before breaking through the Strait of Gibraltar , " UB - 49 " sank six ships , damaging one further . On 9 September 1917 loss of fuel forced " UB - 49 " to change course and make for Cadiz in neutral Spain . Second War Patrol . While Spanish authorities planned to intern " UB - 49 " for the duration of the war , her crew managed to repair the damage to the fuel tanks and bunker enough oil to reach Cattaro . On 6 October 1917 , " UB - 49 " slipped out of the harbour and reached Cattaro nine days later with no fuel left . After refuelling " UB - 49 " sailed for Pola where the boat was repaired . Third War Patrol . On 11 December 1917 , " UB - 49 " left Pola for a cruise in the Gulf of Genoa . Already on the first day , " UB - 49 " was attacked by an enemy submarine . The next day , two Italian sailing ships were sunk , while exchanging fire with a coastal battery at the same time . On 15 December 1917 , " UB - 49 " managed to sink three steamers out of a convoy leaving Genoa , followed by two more the next day . On 22 December 1917 , another two steamers were hit by torpedoes of " UB - 49 " . The last torpedo on this cruise " UB - 49 " used on a British steamer off Naples . Fourth War Patrol . Between 23 January and 13 February 1918 " UB - 49 " operated in the Gulf of Genoa again , sinking several Italian sailing ships , a British steamer and an Italian escort vessel , " G 32 " . On the way back to Cattaro , " UB - 49 " experienced problems with her ballast tanks east of Malta and dived uncontrolled to a depth of . Using compressed air to blow out all ballast tanks simultaneously , " UB - 49 " was able to surface again and continue her journey to Cattaro . Fifth War Patrol . On 5 March 1918 , " UB - 49 " left Cattaro again to operate in the Tyrrhenian Sea . From 13 March 1918 " UB - 49 " pursued a convoy leaving Genoa for Naples and in two days managed to sink three out of four steamers . East of Sardinia , an Italian steamer and a French tug boat fell victim to " UB - 49 " . Between 19 and 21 March 1918 , " UB - 49 " operated in the Gulf of Naples , sinking several Italian sailing ships and shelling the fortifications of Civitavecchia . A fire in one of the dynamo s forced " UB - 49 " to return to base on 25 March 1918 . Sixth War Patrol . " UB - 49 " sailed on 11 May 1918 for her sixth war patrol , which lead her into the Gulf of Lion and the Western Mediterranean . In the last week of May , " UB - 49 " successfully attacked Allied shipping south of the Balearic Islands , sinking three steamers . On 2 June , " UB - 49 " - running low on fuel - turned back to Pola for a major overhaul . When she arrived there on 12 June 1918 , Kptlt . von Mellenthin handed over command of " UB - 49 " to Oberleutnant zur See ( Oblt . z . S . ) Alfred Ehrensberger . Seventh War Patrol . After three months in port , " UB - 49 " went to sea again on 11 September 1918 . Headed for the Western Mediterranean , Ehrensberger was less successful than von Mellenthin . A strong Allied presence of escorts pressed " UB - 49 " under the surface more and more often . Nevertheless , " UB - 49 " sank two ships off the Spanish coast . " UB - 49 " made port again on 12 October 1918 . Eighth War Patrol . When it became apparent that Austria - Hungary ' s situation was untenable , " UB - 49 " was ordered to return to Kiel . Leaving Pola on 29 October 1918 she reached the Norwegian port of Lervik in the last week of November 1918 . Together with most of the other u - boats from the Mediterranean , " UB - 49 " arrived in Kiel on 29 November 1918 . Aftermath . The Armistice with Germany required that all u - boats had to be surrendered to the Allies . " UB - 49 " was handed over to the United Kingdom on 16 January 1919 . In 1922 the u - boat was broken up in Swansea .