1912 - 1919: V (early) Class
Taking the identifying letter from the name of builder, the V Class was Vickers' interpretation of a coastal-type submarine designed to meet the requirements of the 1912 Submarine Committee.
Four of the class were ordered, the first being laid down in November 1912. The principal design feature was in the hull form. Although classed as double-hulled, the V boats were actually partial double-hulled vessels, the double-hull being limited to the middle portion of the boat, with the outer hull fairing into the pressure hull at the forward and after ends.
Vickers carried out a number of tank experiments on several hull forms before opting for this design. The estimated cost of the four V Class submarines was £76,100 each, but this was later amended to £75,799. The diesel engines of the V boats developed 450 bhp at 450 rev/mm and were the first Vickers-built submarine engines to have steel cylinder jackets - previously these had been of cast iron.
The battery consisted of 132 Exide cells - small for the size of boat: the A Class of less than half the displacement carried 120 cells. But the designed submerged speed was still attained, although at the expense of endurance.
Vickers claimed that the V Class could dive to 150 feet as against 100 feet in the conventional submarines of the period. Although the pressure hull sections were far from circular, this depth was possible because the strength of the hull was increased by the external framing between the inner and outer hulls.
The armament of the class was two 18-inch bow torpedo tubes, positioned low in the vessel. Two spare torpedoes, without warheads, were stowed on the starboard side of the torpedo room one above the other, with the warheads nearby on the flat. The torpedo hatch was mechanically operated as in the E Class. Some records state that a 12-pounder gun was fitted, presumably this was after completion.
All four V Class submarines were taken out of service in July 1919.