Fort Kelburne was built on four levels. The guns were 120 feet apart. The front cliff-face was topped with a palisade, a spiked steel fence on top of a concrete retaining wall, to repel attackers on land. A bomb-proof passage was constructed from gun to gun underground, and open galleries gun to gun by rear of main rampart.
The central gorge area was closed by bomb-proof barracks (Officers only) which were loop-holed. The flanks were closed by loop-holed walls returning from sweep of escarp-walls of gunpits to either end of the barracks. There were no ditches. The total length of loop-holed walls was 55 yards.
All underground galleries and gun pits, whether concrete or brick, were dug out of the ground. The concrete was then poured into the boxing and the brickwork laid, after which concrete and brickwork were plastered where required, and over the top, a layer of bitumen was applied as a damp roof course. The whole construction was then covered over with earth to completely enclose these quarters underground.
The cookhouse, eating quarters and the emergency generator (main electrical power coming from the meat works) were housed in two separate buildings behind a corrugated iron fence at the bottom of the tramway which ran from Nguranga Gorge up to the fort. The tramway ran from behind a corrugated iron fence straight up the hill to the entrance to the southern open gallery. A trolley with a flat wooden top was used for transporting shells and supplies up to the fort and was hauled up on the end of a steel cable by a hand winch near the entrance into the open gallery. Up the side of the tramway, ran a path or really a flight of gradual steps. At the bottom near the cook- house there was a guard house from which a guard marched up and down the gorge road outside the corrugated iron fence.
Only the Officers and N.C.Os slept in the barracks in the fort itself. All other personnel slept in bunks in three barrack buildings on the north-east side of the parade ground at the top of the fort. The guard room section of the Officers' quarters was used periodically for recreation and sing-songs, although it wasn�t usual for the trainees to mix very much with the officers.
At the bottom of the hill near the cookhouse there was a small level sports ground used for playing football and cricket etc. The spiked steel fence. ran along the top of the concrete retaining wall overlooking the Hutt Road. It didn't run around the full length of the wall, but just along the portion actually above the Hutt Road itself.
The guns guarded the whole inner harbour and beyond Point Jerningham; two Armstrong six-inch breach loading rifled disappearing guns (Elswick Ordnance Company pattern, 5 tons) mounted on Mk II hydro-pneumatic carriage. Their arc of fire extended from the Petone foreshore to the Wellington esplanade.
As the big guns were not fired very often (only once or twice a year), the ground above the fort became overgrown and after one shot was fired, the blast from the explosion completely cleared all the scrub etc, away. The top of the gun pits were placed high enough so that when the barrels were at their highest angle of depression when aimed into the harbour the shell would clear the top of the spiked steel fence.
In addition to the two six inch guns, there was a 13 to 15 pounder Nordenfeldt on wheels which was kept near the top of the fort and used for aiming practice. This gun was fitted with a Martini-Henri rifle of half inch calibre in line with the barrel and was used to save ammunition on the big guns.
It appears that the two six inch disappearing guns mounted at the fort during the First World War were not identical with the guns originally mounted there when the fort was constructed. The carriages and barrels differed slightly in design, although the date 1886 was found during demolition marked on the barrel of No. 1 gun. The ring gear on which the guns rotated and also the bottoms of the pits differed considerably compared with typical drawings supplied by the Army Department. It is supposed that at the beginning of the First World War, the guns were modified and brought up to date with the latest model of that particular gun at that time.
Targets for shooting practice were in the form of a large trellis to represent a warship, towed across the harbour on the end of a long cable between Ward and Somes Islands by the Janie Seddon. Only about the top 2 feet of the observation point (the steel top and the narrow observation slit) projected above the ground. This was the point from which all the speaking tubes extended into the fort, and also the point from which all the information for sighting the guns came from. The orders to fire also came from here and it was known as fire control. On top of a square concrete stand was a range-finder, which was used for siting onto the target, giving the exact position of it which by speaking tube, was conveyed to the gun pit.
The last period in which the fort was fully manned was during the First World War. At this time, the guns were still in first class condition and the tramway over which shells and supplied were transported from the Ngauranga Gorge Road and through the fort to the magazines and stores, was still in excellent working order.
Soon afterwards the guns were stripped by a scrap metal merchant and all removable metal was taken. The gun pits were then filled in and were later used for foundations for two Railway Department houses. In 1926, when the Tawa Flat railway tunnel was commenced, the area was taken over by the Works Department and used for accommodation for tunnel workers at which time the Railway Department houses were built. Also the road up the hill at the back of the fort was constructed during this period. In 1957 the Makara Country Council controlled the area of land on which the fort was situated. The guard room area of the barracks in the fort itself was occupied until about the end of 1958 by a former Works Department employee and his wife, but they finally abandoned it owing to increasing dampness. Demolition of the fort started during September 1963 and by early December 1963 there was nothing left of it. During the demolition it was found that the guns had been buried in position in the pits. One ended up at Trentham Army Base, while the other is apparently at the Army Museum.