pressure hull and, as events during the war proved, the E Class were eventually designated as being capable of diving to a depth of 200 feet.
Fifty-six E Class were built between February 1911 and August 1917. Of the first twenty-six, 20 were built and completed at Barrow between January 1913 and January 1916, including two built at Beardmore's at Dalmuir and fitted out by Vickers, and six were built at Chatham. The remaining 30 were divided between twelve other shipyards who were entering the field of submarine construction for the first time, including Armstrongs at Newcastle, Cammell Lairds at Birkenhead and Scotts on the Clyde.
A further two boats of this class, AE1 and AE2, were built at
