The Gap Battery was built in 1938, and originally consisted of four 4-inch Mk-VII's. These were four of the six guns that had been at the Saluting Battery at Point Jerningham. (The other two went to Battery Point, in Lyttelton). The guns themselves had originally come from the Battle Cruiser HMS New Zealand (see the article on the 4-inch guns for more information). They were mounted on open gun platforms. A magazine was built semi-sunken into the side of the hill. Two of the guns were removed to Fort Ballance in 1941. The guns eventually had gun shields added to them. They remained in place as late as the 1950s.
The first 12pdr to be emplaced at Fort Dorset had been quickly emplaced WW1 on small concrete pads, on the hillside about 60 yards behind the 6-inch battery. They faced north to cover the Examination Anchorage. Later in the war they were removed and placed on merchant ships. The guns were returned later, but were not re-emplaced until 1925, probably at the same site. In September 1935 the guns were moved yet again, to the more formal emplacements at the Steeple Battery. During the war the emplacements gained a new Command Post, BOP, steel shields and overhead covers. The last 12pdr Battery to be built at Fort Dorset was the Beach Battery, ironically also the only one to remain in any form. The two guns were mounted in February 1942. Behind it a 2-storeyed combined magazine/command post was added in May. The emplacement was abandoned in late 1944 when the Twin 6pdr became operational at Fort Ballance.
