The high-angle directors and rangefinder and their platform were replaced by a new circular platform for the High Angle Control System (HACS) Mk I director by March 1930. By July 1932, the single two-pounder guns and the starboard torpedo director were removed and replaced by a single octuple two-pounder "pom-pom" mount on the starboard side of the funnel and a rangefinder was added at the rear of the bridge roof. The port side mount was installed several years later in the position occupied by the port torpedo director and anti-aircraft directors for both mounts were added to the bridge structure. In 1934–1935, "Rodney" was fitted with a pair of quadruple mounts for Vickers AA machineguns that were positioned on the forward superstructure. The ship was fitted with an aircraft catapult on the roof of 'X' turret and a collapsible crane abreast the bridge was also added in 1937 to hoist the aircraft in and out of the water. A floatplane version of the Fairey Swordfish torpedo bomber was first used aboard, but it was soon replaced by a Supermarine Walrus amphibian. In October 1938 another octuple "pom-pom" mount was added on the quarterdeck and a prototype Type 79Y early-warning radar system was installed on "Rodney"s masthead. She was the first battleship to be so equipped.