instead had the lighter and simpler Mk V twin Bofors mount. This was normally supplemented by two power operated single pom-pom mounts and two 20 mm Oerlikon cannon. They also introduced the all-welded hull into Royal Navy destroyer construction, beginning in Contest, with the "Cr" flotilla all being of all-welded construction. Late delivery of the Mk VI directors delayed completion such that all but one of the "Ch"s, "Co"s or "Cr"s entered service after the end of the Second World War. Only Comet was commissioned before VJ Day, in June 1945, albeit too late to see action. Caprice was the last destroyer built for the Royal Navy to be fitted with the ubiquitous quadruple QF 2 pounder "pom-pom" mounting Mark VII. The "Ca" flotilla were reconstructed in the late 1950s and early 1960s to be modernised for anti-submarine warfare and to serve as fast fleet escorts. One bank of torpedo tubes and one 4.5 in gun was removed, allowing two Squid triple-barreled anti-submarine mortars to be fitted, while the ships' obsolete gun Mk I Type K director was replaced by a modern Mk 6M director as fitted to Royal Navy frigates, and the remaining 4.5 in guns fitted with RPC. Close in anti-aircraft armament was standardised as a single Mk V twin and two single 40 mm Bofors mounts. The ships were also fitted with new bridges; the post-refit bridge differed between the first four conversions (Cavendish, Carron, Cavalier and Carysfort), with open bridges and the later four (Caprice, Cassandra, Caesar and Cambrian) which were given frigate-type enclosed bridges. The remaining "Ch", "Co" and Cr" ships in the Royal Navy were given a less extensive modernisation, with one 4.5 in gun being replaced by twin Squids, modified fire control and a close in anti aircraft armament of 1 twin and four single Bofors guns. Chieftain, Chaplet and Comet were fitted as minelayers. Engineering The class were all fitted with two Admiralty 3-drum boilers with a pressure of at . All had Parsons single-reduction geared turbines, generating at 350 RPM, and driving the two shafts to produce a maximum of ( under full load condition). All were engined by their builders except Cossack and Constance, which were engined by Parsons. Their bunkers could hold 615 tons of oil fuel, giving them a radius of at and at . Ships "Ca" (or 11th Emergency) Flotilla This flotilla was authorised under the 1941