The V and W class was an amalgam of six similar classes of destroyer built for the Royal Navy under the 9th, 10th, 13th and 14th of fourteen War Emergency Programmes during the First World War and generally treated as one class. For their time they were among the most powerful and advanced ships of their type in the world, and set the trend for future British designs. They arrived in time to see service in the First World War. During the interwar period these ships formed the backbone of the Royal Navy's destroyer flotillas until gradually replaced by new construction; by the mid-1930s most had been displaced to the reserve fleet. Most ships survived to make an extensive contribution to the Second World War effort, in the vital role of convoy escort, freeing up more modern ships for fleet action. History The V and W class were the ultimate evolution of British destroyer design in the First World War, embodying the improvements of their predecessors as well as new technological advances. Their lineage can be traced to the River or E class of 1902 that had introduced the classic raised forecastle into the Royal Navy. The of 1905 introduced oil-firing and the resultant economies in size, consumption and crew. The of 1915 had introduced a raised shelter deck forwards, allowing two guns to be carried in the classic superfiring (i.e. one gun fires over the top of the one below and in front of it) "A" and "B" positions. The , also of 1915, introduced a three-boiler, two-funnel layout allowing for a more compact hull and giving increased deckspace and the introduced geared turbines giving on two shafts. Design The new design, originally known as the Admiralty V-class leader, incorporated all these improvements, and also a more sensible layout of the main armament, the amidships gun between the funnels being removed to the aft shelter deck, superfiring over the gun on the quarterdeck. This introduced the ubiquitous "A", "B", "X", "Y" layout for the main armament. New developments, such as director firing for the main armament, triple torpedo tubes and a heavier armament were introduced either from the outset, or as they became available. Ships with triple tubes became the Admiralty W class and those with their armament upgraded to the BL 4.7 in gun became Admiralty Modified W-class ships. Admiralty V-class leaders The Admiralty V-class leaders were the