War Emergency Programme Destroyers - Design Changes

Design Changes

• The P, and 3 ships of the O, flotilla were fitted with 4-inch guns with a new design of tall gunshield. As a result they carried only the Rangefinder-Director Mark II(W) for fire control.
• From the Q and R class onwards a transom stern was incorporated.
• From the S and T class onwards the bow was revised to a design based on that of the Tribal class destroyer, to improve sea-keeping.
• From the Q and R class the main gun calibre returned to 4.7 inches.
• From the R flotilla onwards the officer's accommodation was forwards, instead of aft as was traditional Royal Navy practice
• The S flotilla altered the position of the searchlight between the torpedo tubes with the medium anti-aircraft position abaft the funnel. This more logical arrangement gave the anti-aircraft gun improved arcs of fire in the forward field.
• The S class introduced the new mounting CP Mark XXII for the 4.7-inch guns. This could readily be distinguished from the older mounting CP Mark XVIII of the O, Q and R by its sharply raked face, allowing increased elevation.
• S-class Savage incorporated the new 4.5-inch gun Mark III, in a prototype twin dual-purpose turret BD Mark IV forward and 4.5-inch gun Mark IV in single mountings CP Mark V aft. The former would be introduced in the Battle class destroyer.
• The T flotilla introduced the lattice foremast, to support the ever-increasing weight of masthead electronics.
• The W flotilla introduced the dual-purpose Director Mark III(W), replacing the low-angle Destroyer DCT and High-Angle Rangefinder-Director Mark II(W) in use since the Q and R class.
• The Z flotilla introduced the new dual-purpose Director Mark I Type K and the 4.5-inch gun in single mountings CP Mark V as trialled in Savage. These mountings were based on the CP Mark XXII used in the later 4.7-inch gunned ships; there was no obvious difference.
• The Ch- flotilla introduced the dual-purpose Director Mark VI with full remote-power control (RPC) for gunlaying. As a result one set of torpedo tubes was removed to counter the increased topweight.
• All ships used the Fuze Keeping Clock High Angle Fire Control Computer.