Two gun positions were built to mount the ex-naval guns in their turrets. These were later protected with a "plastic" anti-aircraft roof. One position was built over the ruins of the old west battery and the other partly obscures the north west battery. The barrack blocks were converted and the windows partly blocked to reduce the effects of blast. Several other associated structures, including searchlight batteries for illuminating seaborne targets, a command post and the barracks for the garrison were built outside the original Palmeston fort.