My research for this story began amid the startling news of the chemical attack on the Russian double agent Sergei Skripal and his daughter in Salisbury, and of chemical weapons  being used in Syria.

I knew about mustard gas in WWI, because my great-uncle had been affected by it while fighting in France. Its use had been banned  by the Geneva Protocol of 1925.


Mustard Gas victim WWI

The terrible effects of Mustard Gas in WWI. (Wikepedia)


As the threat of Japanese invasion increased during  WWII, it was decided  that the  RAAF should compile a stock of mustard gas, obtained from Great Britain. This was  a complete shock to me, I had never heard a word about it. The Japanese  had already used chemical weapons  against the Chinese post  WWI and fear they may do so against Australia was very real. The chemical was only to be employed  in retaliation, if the Japanese should act first.

The barrels of gas were stored in disused railway tunnels, including one at Glenbrook in the Blue Mountains of NSW. Naturally it  was a top secret project. The Glenbrook tunnel had previously been used for growing mushrooms. Later  the locals would feel they had been treated rather  like the  mushrooms; kept in the dark and fed bullshit.  It was many years before the horrifying truth about the mustard gas storage and its legacy was revealed.

In 1981 The Canberra Times ran an alarming  piece after an interview with Mr John Humphrys,  who had worked at Glenbrook.

The article mentioned that Dr John England, now a cardiologist in Katoomba, had prepared a submission to a Federal Government inquiry into  WWII hazardous chemicals.  It included statistics  of cancer cases in the Blue Mountains.  Dr England  commented that the situation regarding Glenbrook warranted further investigation. How true that turned out to be!

Problems in handling the mustard gas began while the containers were being unloaded from a freighter  at Sydney’s Glebe Island in August 1942. They had shifted and bumped  against each other at sea, resulting in  abrasion and leakage. Some 36kg  had spilled on board. The men who unloaded the drums had no idea of the dangers involved. Some were badly injured. They were taken to the Royal Prince Alfred Hospital and treated for burns, blisters, breathing problems and loss of vision  A code of silence surrounded the whole affair, from the medical staff  involved to the men  themselves.

One person interviewed for the Canberra Times piece was Mr Alick Stocker, a former instructor in the use and maintenance of the mustard gas.  He told of how the  leaking drums were loaded onto trains bound for Glenbrook and the RAAF base further west at Marrangaroo, near Lithgow.  Stocker said; ‘We often had to decontaminate the rail tracks in the dark and it was not long before we ran out of decontamination equipment.’  He considered that much of the rail line had remained contaminated.


Mustard gas storage at Glenbrook Rail tunnel.

A potentially lethal seat for the maintenance workers at Glenbrook.

Ten years ago RAAF veterans Geoff Burns and Arthur Lewis revisited the tunnel they had worked in. The men were bitter about their experience, feeling they had not been properly informed about the risks involved.

Geoff Burns and Arthur Lewis outside the tunnel entrance in 2008  (Sydney Morning Herald)


Fearing Japanese espionage flights, the military depot at Marrangaroo was designed so that, from the air, it would appear  as a small country hamlet. The administration centre and mess was disguised as Ryan’s Hotel, complete with hitching rail.  That roof top lettering is visible on the building to this day.

WWII fake hotel at Marrangaroo during WWII

Nothing to see here, just a country pub.

Cattle strolled down the main street to help create a bucolic scene, as did dogs.  The cows were harmless enough, but the dogs had been trained to attack intruders.

There was even a ‘butcher’s shop’ (see below). I love the way the horse is looking at the little dog. He might be saying;  ‘Don’t waste your time young fellow, not a single sausage in there. You heard it from the horse’s mouth.’ 



Fake butcher's shop at Marrangaroo

No meat here, mate.



When the war was over the problem arose of how to safely dispose of the  Glenbrook mustard gas.  It was decided that burning it would be the safest option. During February and March 1946, 2,000 tonnes were secretly incinerated in Newnes State Forest. Unfortunately the  exercise  was not wholly successful.  More burning and bleaching was carried out over the next couple of years.

In 1980, more intensive decontamination took place.   2,500 tonnes of soil were removed, taken to an ammunition depot,  burned in a pit and bleached.

There was yet another clean up as recently as 2004.

Eventually the old  Glenbrook tunnel reverted to its former use as a mushroom farm. The most recent  operation  ceased in 2016.  Sadly, the tunnel and its surrounds were left in a terrible condition. It is hoped that the whole site will be cleaned up, and the tunnel opened as a significant historical site.

If you would like to read a broader and more detailed  account of chemical weapons in this country (including the operations at Glenbrook and Marrangaroo) a book written by Geoff Plunkett  may be of interest.  It’s called Chemical Warfare In Australia; Australia’s Involvement In Chemical Warfare 1914-1945.

UPDATE – after this piece was published I was contacted by Geoff Williams. Geoff’s uncle served at Glenbrook and in 1997 he provided evidence to the Federal Government inquiry into Australia’s wartime use of chemicals. You can read his disturbing statutory declaration HERE.

And here is a  story from the ABC about a serviceman who carved his name on a rock at the tunnel.. R. A. Bryan.




  1. What a horrifying story, Pauline! I’m left wondering about all the people who handled this stuff and what the later effects were – not least about the wharfies/dockers who unloaded it, and crew of the cargo ship which transported this deadly cargo.
    We hear about the use of chemical weapons, but only recently with the Salisbury case here in UK, has the reality of it hit home. Mustard gas not so sophisticated, but even so…
    For you, with Glenbrook so close to home, no wonder you’ve found it disturbing.

    • Pauline

      Yes, all so creepy, Ann. Some of the men who served there refused to go to ANZAC Day services because they felt they had not been properly informed of the risks. Their service records were destroyed. Oddly enough the doctor who completed the submission to government back in the 1980s was my initial cardiologist when I became sick with Churg Strauss Syndrome. Naturally this little piece has made a big impact on the Blue Mountains FB groups.

    • Alick Stocker was my grandad. The mustard gas got in his ears and he had awful pain and hearing loss. He was luckier than some

  2. Pauline,

    Glenbrook wasn’t the only railway tunnel in NSW used as a storage base for chemical weapons – Clarence and Picton were also used.

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