In the American design no periscope was fitted and the only way to see was to look through a scuttle in the low conning tower. A periscope designed by Capt R H S Bacon (Superintendent of Submarines at Barrow) and built by Howard Grub - head of a Dublin opticians - was fitted to the Hollands. This was a hinged periscope, raised and lowered on a ball and socket joint on the hull. The viewed image was only upright when ahead; when abeam it was on its side; and when astern it was upside down.
During the Holland construction programme, association with the Electric Boat Company was severed and Vickers seriously began the task of designing submarines themselves. (It is interesting to note that Vickers' association with the Electric Boat Company was renewed in the 1960s, with the construction of Britain's first nuclear-powered submarine HMS Dreadnought.)
