 The submarine was ordered as U @-@ 11 from Germaniawerft of Kiel as the last of five boats of the U @-@ 7 class for the Austro @-@ Hungarian Navy . After the outbreak of World War I in August 1914 , the Austro @-@ Hungarian Navy became convinced that none of the submarines of the class could be delivered to the Adriatic via Gibraltar . As a consequence , the entire class , including U @-@ 11 , was sold to the German Imperial Navy in November 1914 . Under German control , the class became known as the U 66 type and the boats were renumbered ; U @-@ 11 became U @-@ 70 , and all were redesigned and reconstructed to German specifications . U @-@ 70 was launched in July 1915 and commissioned in September . As completed , she displaced 791 tonnes ( 779 long tons ) , surfaced , and 933 tonnes ( 918 long tons ) , submerged . The boat was 69 @.@ 50 metres ( 228 ft ) long and was armed with five torpedo tubes and a deck gun . 
