 The German Imperial Navy ordered its first fifteen Type <unk> I boats on 15 October 1914 . Eight boats — numbered <unk> @-@ 1 to <unk> @-@ 8 — were ordered from Germaniawerft of Kiel , and seven boats — numbered <unk> @-@ 9 to U @-@ 15 — from AG <unk> of <unk> . After two of the class , <unk> @-@ 1 and <unk> @-@ 15 , were sold in February 1915 to ally Austria @-@ Hungary ( becoming U @-@ 10 and U @-@ 11 in the Austro @-@ Hungarian Navy ) , the German Imperial Navy ordered <unk> @-@ 16 and <unk> @-@ 17 from <unk> . A further three for Austria @-@ Hungary — U @-@ 15 , U @-@ 16 , and U @-@ 17 — had been ordered from <unk> by April , bringing the total number constructed to 20 . 
