 <unk> @-@ 1 and <unk> @-@ 2 were laid down on 1 November 1914 at the Germaniawerft yard at Kiel . <unk> @-@ 1 was launched on 22 January 1915 , just 75 working days later . <unk> @-@ 2 's launch followed on 13 February . Among the <unk> boats , <unk> @-@ 9 was laid down first , on 6 November 1914 , and launched on 6 February 1915 , a week ahead of <unk> @-@ 2 . These first three boats launched underwent trials in home waters , but most of the other members of the class were shipped via rail and underwent trials at their assembly point . 
