For anti-aircraft (AA) defence, they carried a single quadruple mount for the  QF two-pounder Mk II "pom-pom" gun and two quadruple mounts for the 0.5-inch (12.7 mm) Mark III machine gun. Low-angle fire for the main guns was controlled by the director-control tower (DCT) on the bridge roof that fed data acquired by it and the  rangefinder on the Mk II Rangefinder/Director directly aft of the DCT to an analogue mechanical computer, the Mk I Admiralty Fire Control Clock.
For anti-aircraft defense, they had a single quadruple mount for the QF two-pounder Mk II "pom-pom" gun and two quadruple mounts for the 0.5-inch (12.7 mm) Mark III machine gun. Low-angle fire for the main guns was managed by the director-control tower (DCT) on the bridge roof, which transmitted data from it and a rangefinder directly aft of the DCT to an analogue mechanical computer, the Mk I Admiralty Fire Control Clock.