WWII Buildings, Oliver Hill Battery and Signal Ridge, Wadjemup/Rottnest Island

Child Places

• 09146 Battery Observation Post & Timber Signal Station
• 27033 WRANS House, Wadjemup/ Rottnest Island

Statement of Significance

In 1935 as part of an overall plan to extend and modernise the coast artillery defences for defended parts throughout Australia, preliminary work for the installation of heavy guns on Rottnest Island was commenced partly as a result of the British Governments decision to fortify Singapore. Progress was slow probably through indecision as to whether the development of air power should be given a higher priority. The original conception included standard 3 gun mounting and further delays occurred when the British Government could not release the third gun – resulting in plans being modified as a two gun battery. As such it is believed that this battery is the only one left in the Commonwealth with its guns still mounted. The natural constraints of building an installation of this magnitude involving the transport of most materials and fittings by barge and railway track from the mainland are formidable. The effectiveness of construction techniques are reflected in the soundness and freedom from damage, amongst other menaces, through water penetration of the underground installation. The complex demonstrates the end of an era of coastal defences which was primarily intended to protect the important port installations and its ships from enemy vessels, and to deter attemps to seize the port as part of an invasion plan. At the time they were installed these 9.2 inch counter bombardment coastal defence guns were the most modern in any coastal fortress. Whilst the battery was intentionally located to suit the function of the battery, present proposed future development as a museum can be seen as contribution to the enhancement of this spectacular site from many aspects. From information available it appears that this battery contains the last 9.2 inch coast defence guns mounted in situ in the British Commonwealth and as such are worthy of preservation as an historic example of a 20th century coast defence battery.

Physical Description

Description RAILWAY. 3ft 6 inch gauge tracks of light rails spiked to jarrah sleepers including 15 manually operated turnouts. (10,000 sleepers and 10 tons of spikes used). Embankments and sand hill cuttings replanted and camouflaged and have withstood the ravages of erosive action. Much of the railway equipment was second hand rolling stock and rails recovered from the abandoned Naval Base site at Coogee. Parts of the track are still visible in the reserve and the remainder is possibly concealed under filling marl. Tracks last used 1960. The Rottnest Island Board would like to restore the track but the cost of ballasting presently prevents further consideration. TUNNEL COMPLEX The concrete gun emplacements, underground magazines, engine rooms, fortress and battery plotting rooms, concrete observation posts were constructed by civilian contractors under the supervision of the Commonwealth department of the Interior. The underground facilities constructed from reinforced concrete in an excavation most likely later backfilled, include a powerhouse which contained two 180HP Ruston Hornsby Diesel Engines (one hopefully to be replaced soon) coupled to two 120 KVA electric generators, fortress and battery fire control rooms, hydraulic pump chambers, cordite and shell magazines, first aid casualty bays and air compressors, all interconnected with underground tunnels. All underground plant and equipment has unfortunately been removed, including a sophisticated communications system, most furniture, rifle racks, storage racks, shelving etc. Restoration work by the Rottnest Island Board is in progress. GUNS: It is believed that one of the 9.2 inch gun barrels was held in reserve by the Royal Navy in Hong Kong until taken over by the British Army in 1910. The other barrel is believed to have been part of the shore battery at Portland, Dorset, U.K. iin 1919. Both barrels were re-tubed and modified at the Royal Gun Factory in 1935 – 36. The letters E.O. C. 1901 stamped on the breech refer to the original barrels having been manufactured by the Elswick Ordinance Company (later Vickers) in 1901. 9.2 inch guns MK 10 on MK 7 mounting total barrel length 11.2 metres revolving weight approx.. 140 tons (142.2 tonne) Maximum range 33.5 km depending on charge etc. BATTERY COMMAND POST Three storey brick building contained range finding and fire control instruments to pass fire direction and control information to the battery or fortress plotting rooms or direct to the guns or any other battery through a complex communications system within the Fremantle fortress system.

History

Assessment 1982 Defence Installation, Installed 1936, all working equipment removed 1963 Includes: all construction on Commonwealth land; reserve on both surface and underground including railway installations, tunnel complex and gun mountings and at Signal Ridge near the main light house - 3 storey brick battery command post building

Uses

Historic Themes

Creation Date

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