Whitby Class Frigate - Armament

Armament

The armament was based around two Limbo Mark 10 anti-submarine mortars. This allowed a three-bomb salvo to be placed both above and below the target, creating a convergent pressure wave more likely to assure a kill. The Limbos were mounted in a well on the quarterdeck, with a 360° arc of fire. Again, wartime experience had shown that the quarterdeck, perhaps not an obvious location for an ahead throwing weapon, was indeed the best location for such weapons where they were out of the spray towards the front of the vessel. The Limbo mortars were controlled by three sonars, the Type 174 search set, Type 162 target classification set and the Type 170 'pencil beam' targeting set. The lattice foremast carried the radar Type 293Q target indication set and the Type 974 navigation set, and a Type 277Q height finder was carried on a stump mast between the bridge and the mainmast. These sets were all derived from units of second world war vintage.

Carrying the Limbos aft allowed the forecastle to be left clear for the twin 4.5in Mark 6 gun for anti-surface and limited anti-aircraft fire, controlled by a Mark 6M director with radar Type 285 mounted behind the bridge. Further anti-submarine capability was to be afforded by twelve 21 inch Mark 20E "Bidder" anti-submarine homing torpedoes, carried in fixed tubes; Four pairs were fixed firing forward on either beam, with a trainable pair behind these on each side. Ultimately the E version of the Mark 20 torpedo was a failure as it was not nearly fast enough to catch its intended target, and the tubes were removed (where they were fitted at all) and the torpedoes never deployed.

Self-defence against aircraft was provided by the elaborate STAAG weapon, a complex and ultimately failed exercise in engineering. The STAAG, or Stabilised Tachymetric Anti-Aircraft Gun, consisted of a two Bofors 40 mm L/60 guns, the radar Type 262 fire control set and a tachymetric computer (predictor). All this was carried on a common, stabilised, powered-operated gun mounting. Intended to function much as the modern CIWS does, this weapon was ahead of the limits of technology at the time and was overweight, overly complex and its sensitive valve electronics were a maintenance nightmare. Ultimately STAAG would be replaced by a simple and ubiquitous Bofors 40 mm gun on the single Mark 7 mounting.