The four single 4.7-inch guns were increased to three twin mountings (originally four twins), and two five tube banks of torpedo tubes. The anti-aircraft weaponry was not significantly improved, however, and this was a serious flaw. In 1940 and 1941, the anti-aircraft establishment was increased in all ships. Their after torpedo tubes were landed and replaced with a single 4-inch gun on a high angle mounting. The ineffective 0.5 inch machine guns were replaced with single 20 mm Oerlikon guns, and another pair were added on the searchlight platform, amidships. Further modifications took place in 1942, upgrading the single Oerlikons and reinstating the aft torpedo tubes. The radar installations were frequently enhanced during the ships' service.