Both "North Carolina" and "Washington", designed prior to radar, were originally fitted with many fire-control and navigational optical range-finders. The former lasted until 1944, when it was replaced by a Mark 27 microwave radar—though it was supplemented by a Mark 3 main armament fire control radar. The range-finders were removed in favor of additional 20 mm guns sometime between the end of 1941 and mid-1942. In addition, the ships were commissioned with two Mark 38 directors and were originally fitted with a CXAM air search, two Mark 3s and three Mark 4 secondary armament.