Virtual
War Memorial
Australia

The anti-aircraft defence of Horn Island was augmented by the 34th Australian Heavy Anti-Aircraft (HAA) Battery, which arrived at Thursday Island on 14 October 1942. The 34th HAA was accompanied by the 157th Australian Light Anti-Aircraft (LAA) Battery, equipped with 40mm Bofors guns to provide low level protection. The men of 34th HAA Battery commenced unloading guns, equipment and camp stores at Horn Island jetty on 15 October 1942.

On Horn Island the 34th HAA Battery was split into 'A' and 'B' Sections each forming a 'Class A' Heavy Anti-Aircraft Gun Station (GS) of four Quick Firing (QF) 3.7-inch guns and one QF 40mm Bofors gun for close air defence. The first camp was formed on Double Hill, west of the airfield, which was initially known as Section 'A' and subsequently became GS 442. On 16 October the men began excavation of gun emplacements and the construction of kitchens, stores, ablutions and latrines. A supply of drinking water was another early problem faced by the unit. By November 1942, with the wet season approaching, priority was given to the completion of the reinforced concrete structures for the gun stations.

Each gun station would consist of four 3.7-inch anti-aircraft guns on static mounts within in-ground gun emplacements of octagonal shape. The interior walls of each gun emplacement contained recesses where ready ammunition for each gun was stored. The guns were arranged around a reinforced concrete semi-underground Command Post (CP). The standard CP design included a roofed plotting room plus open concrete pits outside for a height finder and predictor (a mechanical computing machine that predicted the future position of a target). Nearby were four magazines of reinforced concrete.

By 10 December GS 442, along with Section 'B' GS 443 at King Point north-east of the airfield, were operational and ready for action except that no ammunition had arrived. The 3.7-inch ammunition finally arrived at Horn Island on the last day of December 1942. The guns at GS 443 were successfully proof fired on 2 January 1943 and at GS 442 on the next day. All ammunition was stored on site under cover, until construction of permanent concrete magazines (which occurred by the end of May 1943). On 30 January 1943 the battery took delivery of an AA No.1 Mk II short range anti-aircraft radar transmitter and receiver (also known as GL 2 or AA Mk2 Radar) for GS 443. By the end of June 1943 camouflaging of GS 442 was well underway. Gun emplacements for GS 443 were completed during July and camouflaging commenced.

In late 1943 the 34th HAA Battery was reformed as 131 Australian HAA Battery, 51 Australian Anti-Aircraft Regiment (Composite), Royal Australian Artillery. The redesignation combined the 34th Australian HAA Battery, 157th LAA Battery and 74th Searchlight Battery together into one composite unit.

"Extract from Horn Island Airfield"
http://www.ww2places.qld.gov.au/places/?id=770