K Class submarines were the most bizarre and ill-fated submarines of the First World War period. Their conception, in. the spring of 1915, arose from the demand for a submarine that could accompany the Grand Fleet at speeds of up to 24 knots. A 1913 Admiralty design using steam propulsion was adopted and, given the outline particulars, form and general arrangements, Vickers were requested to proceed with the detailed drawings.
The first-of-class, K3, was laid down by His Majesty the King in May 1915 and was completed at Vickers within 15 months of being ordered. As a result of her trials, additional fans were fitted in the turbine room to combat the very high temperature