The Glenbrook Tunnel is a heritage-listed single-track former railway tunnel that has also seen use as a mustard gas storage facility and as a mushroom farm. It is located on the former Main Western Line (since deviated) at Glenbrook, New South Wales, Australia. The Department of Railways designed the tunnel and built it from 1891 to 1892. It is also known as Lapstone Hill tunnel and Former Glenbrook Railway and World War II Mustard Gas Storage Tunnel. The property is owned by Blue Mountains City Council and Land and Property Management Authority, an agency of the Government of New South Wales. It was added to the New South Wales State Heritage Register on 5 August 2011. The railway tunnel was originally part of the Glenbrook 1892 single-track deviation, which bypassed the Lapstone Zig Zag across the Blue Mountains. It is long and is constructed in an 'S' shape with a gradient of 1:33.
The tunnel was built to the east of Glenbrook railway station and opened on 18 December 1892. Due to the steep gradient, seepage keeping the rails wet causing slippage, poor ventilation and planned duplication of the track, plans were drawn up to bypass the steep route. Trains commonly stalled in the tunnel for some time before having to back the locomotive out of the tunnel for another attempt. The tunnel was closed on 25 September 1913, and was utilised for growing mushrooms. In 1942, during World War II, the Royal Australian Air Force (RAAF) stockpiled bulk mustard gas stocks in preparation for a possible Japanese chemical weapons attack. The facility was known as No. 2 Sub Depot of No. 1 Central Reserve RAAF and was vacated by the RAAF after the war. It features in the "Alcatraz Down Under" episode of Cities of the Underworld on the History Channel.
in July 2021, the local state member Stuart Ayres announced that the NSW Government had allocated $2.5 million to progress the opening of the tunnel for public recreation
History Use as a railway tunnel
The original line of railway was opened in 1867, scaling the escarpment above Emu Plains by the Lapstone Zig Zag. At the top of the Zig Zag the railway followed the route now occupied by the Great Western Highway through Glenbrook as far as Blaxland. When increased rail traffic caused delays on the Lapstone Zig Zag, it was decided in 1891 that a tunnel should be built bypassing the Zig Zag. The tunnel and its new approaches were designed to form an elegant S-shape, starting at the Bottom Points of the Zig Zag and ending at old Glenbrook station (now demolished, on the present Great Western Highway).Blue Mts Heritage Study.
The building of the tunnel in 1891-2 was contracted to George Proudfoot, whose labourers and their families were established in two substantial camps at either end of the works, one at Glenbrook, the other at Lapstone. Sir Arthur Streeton's famous painting 'Fire's On!', saw the building of the tunnel and the fatal blasting accident which killed Thomas Lawless become a part of Australian mythology as well as railway history. Streeton was spending three months at Glenbrook at the end of 1891 where he was studying and painting the landscape. He had become interested in the construction of the railway tunnel and the engineering feat that was the Zig Zag Railway. The tunnel was also depicted in several other works, both informal and informal. Among these were Cutting the Lapstone Tunnel (1892) and Sketch - Blue Mountains (1891).
The new tunnel opened to traffic on 18 December 1892, but it was never a success, because of the steep incline and the suffocating atmosphere particularly in the west-bound trains. Traffic flow and water dripping from the roof also caused engines to slip badly on the reverse curve. The problem was finally addressed after the Lithgow Zig Zag deviation was completed in 1910 and the railway gangs were moved to Glenbrook. Bypassing Glenbrook Tunnel involved some major works, including a new viaduct over Knapsack Gully to the east and the new line then ran through virgin country south of the old alignment as far as the present Lapstone station and then turned west through a short tunnel under The Bluff and finally north to the present Glenbrook station.
Initially it was planned to continue using the 1892 Glenbrook Tunnel for up trains. When the new deviation opened on 11 May 1913 the tunnel was still used for east-bound trains. However, the deviation was quickly duplicated and a new "up line was activated in September. Glenbrook Tunnel was last used for trains on 25 September 1913 and old Glenbrook station was closed. The lines in the tunnel were raised and the tunnel left to quietly decay.
In 1913 the Glenbrook tunnel was leased from NSW Railways by Herbert Edward Rowe, an out of work master builder. Previously a Stan Breakspear had fenced off an area close to the tunnel where he kept a bull. The Rowes had the idea of growing mushrooms in the tunnel. They created living quarters from an old circus tent, a small cave and a culvert under the highway. Herbert Rowe built his own mushroom growing beds which were three metres wide with a narrow path down the left side for access and working space. About three quarters of the length of the tunnel was taken up by the beds. When the Rowes renewed their lease in 1936 the Commissioner of Railways warned them that in the event of war, they would be given three months notice to vacate the site. The Rowes are believed to have actually been given only one weeks notice to vacate the site when war broke out in September 1939.
In 1930 Australia ratified the 1925 Geneva Protocol which banned the use of asphyxiating, poisonous or other gases in times of war for offensive purposes, following the experiences of chemical warfare during World War I.
Weapons storage facility
Although tear gas was used as early as 1914, it was not until 1915 that poisonous gases were introduced into the battles of World War One. The first was chlorine gas which was introduced by the Germans at the Second battle of Ypres in April 1915. This was followed by the use of phosphene Gas, also introduced by the Germans. These attacked victims' respiratory organs causing coughing and choking.
The Germans used Mustard Gas, a more advanced gas, for the first time at Riga (or Yperite) in September 1917. It caused both internal and external blistering in its victims. The blistering was often delayed and remained in the ground for weeks afterwards making capture of infected trenches dangerous. Protection against mustard gas was far more difficult than previous gases. Casualties decreased during the war with increased preparedness and death from gas became less common. However, often those who were exposed were often unable to seek employment once they were discharged from the army due to the gases effects. Following the Armistice the use of gas was viewed with horror, bringing about the Geneva Protocol. While the Protocol prevented signatories using gas for offensive purposes, it did not prevent a nation from manufacturing or importing chemical weapons for retaliatory purposes.
The Geneva Protocol was drawn up and signed at the conference for the supervision of the international trade in arms and ammunition, which was held in Geneva under the auspices of the League of Nations from 4 May to 17 June 1925. France suggested that a protocol be drawn up on non-use of poisonous gases. At Poland's suggestion the prohibition was extended to bacteriological weapons. In the years prior to World War II most major powers ratified the protocol, except the U.S. and Japan. The British reserved the right to waive the protocol if in time of war their enemies disregarded the terms of the agreement. Countries around the world have continued to ratify the Protocol until at least 1991.
Australia's ratification of the protocol was influenced by the experiences of Australian World War One soldiers who had suffered from the deadly and debilitating effects of gas exposure, particularly on the Western Front. Many were killed or maimed as the result of chemical attacks. The physical effects on survivors were clearly visible to those at home upon their return.
Use during World War II
By 1937, two years before World War II commenced, Australia was already giving preliminary consideration to the need for procurement of gas for war time defence purposes. Early in 1942 the Japanese southward advance, particularly the fall of Singapore, caused Australia to prepare for possible invasion. Of particular concern was whether Japan would use chemical weapons as it had in China. Australia requested chemical warfare stocks from Britain in March. The response from Britain to supply Australia was swift and the first supplies docked in Australia in May 1942. Later stocks would also come from the United States. Australia would eventually hold close to 1 million individual chemical munitions weapons, including at least 16 different types of mustard gas. Thirty-five types of chemical weapons were eventually located at fifteen major storage depots across Australia.
The first stocks of chemical weapons destined for the RAAF were stored in the Blue Mountains while those for the army went to Albury. Naval stocks were stored at the Newington Armory in Sydney. The RAAF stocks were stored in disused tunnels, chosen because of the lower fluctuation in temperature, protection from high temperatures and constant humidity. In places such as Malaya, caves were used for the same purposes and the tunnels were anticipated to simulate the same conditions as the caves. Industrial scale production or bulk manufacturing of chemical warfare agents did not and has not taken place within Australia, although some chemical agents have been produced here as by-products of other industrial processes or in bulk for other purposes. There has also been small scale manufacture of chemical agents for experimental and testing purposes.
The Glenbrook tunnel was one of fifteen bulk chemical storage facilities established in Australia - seven in New South Wales, six in Queensland, one in the Northern Territory and one in Victoria. Six were supervised by the United States, including Kingswood in NSW, and the remainder by Australia. Only four of these included tunnels for storage purposes. These were Marrangaroo, Glenbrook and Clarence in the Blue Mountains and Picton south of Sydney. They were all Australian supervised sites. Marrangaroo and Glenbrook were the first of the tunnels established followed by Picton and then Clarence. The Picton tunnel was constructed as part of the original main southern railway line. The remaining three were a part of the Zig Zag railway line. The four tunnels formed the base for the Royal Australian Air Force's No. 1 Central Reserve. The headquarters for No 1CR were based at the combined RAAF-Army depot at Marangaroo, several kilometres from the Marangaroo tunnel. No. 1 CR acted as a central depot for chemical and non chemical stocks and as a replenishment centre for NSW. The location of the tunnels also placed them out of the range of aircraft carriers and out of aerial view, thus protecting them from air attack.