Stony Batter

Stony Batter
Waiheke Island, Auckland, New Zealand
One of the gun emplacements
Type	Military defense
Site information
Controlled by	New Zealand Department of Conservation
Open to the public	Yes
Site history
Built	1943

Stony Batter is a historic defence installation at the northeastern end of Waiheke Island, Auckland, New Zealand. It is sited within a 50-acre (200,000 m²) scenic reserve of the same name, owned by the New Zealand Department of Conservation (DOC). The park serves double duty as a historical (Category 1 Historic Place) and nature reserve, containing unusual rock formations, three significant bush blocks and three concrete gun emplacements with an extensive tunnel system, reputed to be the largest in New Zealand.

Stony Batter was of part of a counter-bombardment battery system progressively being installed in the Hauraki Gulf from the 1930s. Composed of various gun batteries, such as at Whangaparaoa, Motutapu Island and at Stony Batter, as well as having observation posts such at Rangitoto Island (command post) and Tiritiri Matangi Island, it was supposed to engage enemy naval forces entering the inner gulf. Ranges would have been too far beyond the line of sight (over 30 km, thus the need for a complex set of observation points and communication lines), as well as at least initially beyond the range of most enemy ships' ability to retaliate.

While approved in 1939, construction was delayed for cost reasons until German raiders were sighted in New Zealand waters during 1940-1941, as well as the war entry of Japan in late 1941, suddenly turned it into a high-priority project. In 1942, the site on Waiheke was chosen, but it took until early 1943 before the Public Works Department was finally tasked with construction after other contractors declined the job. Delays were caused by the remote location, which at first had no road access, and also by the fact that the project was kept in strict secrecy, requiring with a large degree of self-sufficiency during the construction period, complete with its own living facilities and machine shops. The new battery was generally referred to only as A2, to conceal its location.

The tunnels and underground chambers were quarried by hand, with formwork for the walls and ceilings, then filled with concrete (reinforcing steel was not used due to shortages). Aggregate was obtained from the prominent rocky outcrops, giving Stony Batter its name. The tunnels and chambers where designed based on plans of the Tawa Flat railway tunnels project. The work on the installations, sans guns, was completed behind schedule in 1944, and had by then ballooned from initial estimates of £140,000 to £327,966, excluding the costs of the guns. Construction of the battery was, however, considered a major feat of engineering, carried out under particularly difficult circumstances. As the tides of war turned, only two guns were installed, one in 1944, and one in 1948. The third gun was cancelled before shipment. Never fired except for testing and training purposes, the guns were dismantled and sold for scrap in 1961.