H.M.S. Petard was one of the eight 'Paladin' or 'P' class of destroyers ordered for the fleet on 2nd October 1939, just weeks after the outbreak of the Second World War. Curiously, since she was not the nameship of her class, Petard was laid down first (in 1939; none of the other 'P's' were begun until 1940 or 1941) although her name was intended to be Persistent. Built by Vickers, Armstrong on the Tyne, she was launched on 27th March 1941, by which time she had assumed her new name, and was ready for sea before the year's end. Like all her sisters, she displaced 1,550 tons, measured 345 feet in length with a 35 foot beam and carried a main armament of 4-4.7in. guns.
During a relentlessly busy wartime career, her most memorable encounter with the enemy took place on 30th October 1942 when, in company with her sister Packenham, another destroyer Hero and two escort destroyers, she depth-charged and forced to the surface the German submarine U-559 north-east of Port Said. As soon as the U-boat broke surface, Petard opened fire and scored a direct hit on the conning tower thereby forcing the crew to abandon their submarine. Immediately afterwards, Lieutenant Anthony Fasson (Petard's first officer) and two crew dived into the sea, swam over to the stricken U-boat and boarded her. Before she sank, taking Fasson and one of the other men with her, they managed to retrieve numerous secret documents, one of which proved to be a priceless set of cribs with which the 'Shark' Enigma codes could be broken. Once the cribs reached Bletchley Park and were put to use, allied shipping losses in the Atlantic halved in early 1943 and there is no doubt that millions of tons of shipping were saved; as one naval historian has put it: "Few acts of courage by three individuals can ever have had so far-reaching consequences."
Surviving the War, Petard was converted into an 1,800-ton frigate in 1956 and eventually scrapped in 1967.