Photo:- via Sylvia Stoltz

Brook Island Group


First Brook Island Trial - 21st January 1944
by Sylvia Stoltz

The first Brook Island trial was a step into the unknown with personnel wearing impregnated clothing which had been tested previously only in a certain concentration of gas vapor.

As it happened the concentration of gas on this trial proved to be much higher than any previous testing but fortunately the clothing passed the test.

North Brook Island, 22 miles off the Queensland coast from Cardwell, was chosen because it was uninhabited and was similar  to the  islands in the SW Pacific where it was feared that the enemy might use mustard gas against the Allied Forces in action there.

There was an urgent need to learn what effect mustard gas would have on the troops and how best to protect them and retaliate.

For the first trial a base camp was set up on South Book Island and the US landing craft ferried personnel and equipment to and from North Brook Island.

In this trial six American Liberators dropped 90 bombs over the island whilst personnel from the A.CW.R. & E.S. unit from Innisfail waited offshore in the landing craft.  At a given signal personnel (including five service-women) wearing full protective clothing and respirators landed on the island and proceeded to previously rehearsed positions where they carried out allotted tasks. Sampling was continued for several days .



Second Brook Island Trial - 4th March 1944
by Sylvia Stoltz

The second Brook Island trial was planned on a much larger scale than the first.

The base camp was set up in tents along the beach at Hinchinbrook Island, then uninhabited.

The procedure established on the first trial was followed but a much larger number of personnel was  involved.

On this trial Beaufort bombers dropped a total of 159 bombs on the island and there were 43 sampling points.

The aim of the aerial attacks was to assess the efficiency and spread of the contaminant.

Full details of this trial can be seen in a film which was made by photographers Stan Adams and Hal Hoffman.

VCR video or DVD of this film titled “Brook Island Trial March 1944” can be purchased from the Australian War Memorial  Film Archives.   ID Number F05747.

There was an American ship anchored off Hinchinbrook Island on 6th March 1944 (two days after the second Brook Island bombing). On the evening of that day Capt. Skipper took the AWAS, Lt. Simondson, out to the ship (in the landing craft) and she brought back to us Sao biscuits and cheese which was a luxury that we had not enjoyed at Innisfail. I do not recall her giving any information about her visit to the ship.



Third Brook Island Trial - April/ May 1944
by Sylvia Stoltz

The Third Brook Island trial was under the command of US Captain Howard Skipper.

The planes used for dropping bombs on the island were American Vultee-Vengeance Dive-Bombers and American M47 bombs were tested. There was also testing of aerial spraying of mustard gas on a coral beach on North Brook Island.

Trials were carried out over several days with the usual chemical sampling and meteorological observations.

Further trials were carried out using high-explosive bombs in order to make comparison with the effectiveness  of mustard bombs.

Mustard gas bombs did not contain explosives but shattered on impact and spread contamination.

Several days were spent analysing the results.



Photo:- Stan Adams

US Army Captain Howard Skipper in charge of the 3rd Brook Island Trial.


Howard Skipper was a CW physiologist attached to ACWR & ES to liaise with American CWS. He was able to requisition for landing barges complete with US Marine crews for carrying out the Brook Island trials. He also arranged for six B-24 Liberators from Charters Towers to drop mustard charged bombs on North Brook Island for the first Brook Island Trial on 21 January 1944.

On 3 December 1943, a decision was made that up to 25  RAAF aircrews would be attached to the USAAF's Fifth Air Force to gain experience with B-24 Liberators as the RAAF were due to receive this type of aircraft in the near future. Five Australian crews were attached to a USAAF unit at Charters Towers. The Captains of these crews were:-

Sqn. Ldr. John Brook "Long John" Hampshire (0380)
Sqn Ldr. Jack O'Brien
Sqn. Ldr. Bill Rehfisch
Sqn. Ldr. Russell Charles Walter "Rusty" Rayson (03100)
Flt. Lt. Gordon Alfred Fosbery "Mick" Jaques (260806)


liberator.jpg (11693 bytes)

B-24 Liberator


One of the more notable flights they took part in was on 21 January 1944. After their briefing they were met at their aircraft by a US Army chemical-warfare specialist, who had earlier supervised the loading of mustard gas bombs. These bombs were over a metre long and about 15 cms in diameter, weighing about 45 kgs. Each B-24 Liberator carried 60 mustard gas bombs.


Photo:- via Sylvia Stoltz

Photo of Brook Island Group from the opposite direction


The five RAAF crews took off along with the Commanding Officer at Charters Towers, Lt. Col. Joss Crowder. Flying for 90 minutes, at less than 1,000 feet to minimise the chance of a drop in pressure causing a leak, they bombed a small island in the Great Barrier Reef (assumed to be Brook Island).

Sqn Ldr. Hampshire had apparently been advised by Lt. Col Crowder that 50 volunteers from US military prisons were used as guinea pigs for the mission. They had been promised freedom if they would occupy underground tunnels during the bombing mission.  Hampshire was apparently told by Crowder that all 50 prisoners had died in this mustard gas experiment. I have not been able to confirm this story via other references and Geoff Plunkett, well known Chemical Warfare researcher, is adamant that this story is untrue.


Photo:- via Sylvia Stoltz

North Brook Island


Photo:- via Sylvia Stoltz

Coral beach on North Brook Island used for American mustard spray trial on
30 April 1944 and for an American mustard bomb trial on 4 May 1944.


Photo:- via Sylvia Stoltz

Smoke from H.E. bomb test on North Brook Island


Photo:- Stan Adams

Group on Brook Island beach before a trial


Photo:- Stan Adams

Sylvia Linda Stoltz (VF396141) and Maisie Gertrude Dart (V503228) with a group on Brook Island
beach before a trial. They were recovering from sea sickness after the journey from the mainland and
waiting for the arrival of the Beaufort bombers to drop the mustard bombs on North Brook Island.


Photo:- Stan Adams

Sampler at sampling point on North Brook Island


Sylvia was transferred from 5 AWAS Admin. Cadre to the "Australian Chemical Warfare Research & Experimental Section" on 5 November 1943 and was transferred from Vic L of C to QLD L of C. She wore Land Headquarters (LHQ) colour-patches.

Sylvia Stoltz (VF396141), Australian Womens Army Service, was a Meteorology Section Assistant attached to the Australian Chemical Warfare Research and Experimental Section (A.C.W.R. & E.S.). As well as carrying out secretarial duties for Frank Pasquill (UK) Sylvia was trained to carry out elementary meteorological observations at field trials. Sylvia carried out meteorological observations in 31 field trials, 17 of which used mustard gas in bombs, mortars and in ground contamination. Sylvia took part in all three of the bombing trials on North Brook Island.

Diana West, Maud Murphy and Marie Matthews also worked on all three Brook Island trials as well as Mustard Gas trials in rain forest near Innisfail from November 1943 to May 1944. They often worked until midnight in the laboratory. With only three laboratory assistants and an inadequate number of "sampling" personnel, the chemistry girls were tested to the limit and were exhausted until relief came with the addition of three AAMWS in March 1944.


Australian Chemical Warfare Research
and Experimental Section, Innisfail


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The following information is part of a response by Senator Newman - The Minister for Defence - providing an answer to a "Question on Notice" by Senator Woodley in the Australian Senate on 25 August 1997:-


beaufort.jpg (13398 bytes)
Bristol Beaufort


The `Brook Island Trial' took place on North Brook Island in February 1944. It was the culmination of various tests which had been conducted in the Innisfail area.  Aircraft weapons, comprising both gas filled bombs and various types of gas spray were tested using Beaufort bombers from Bowen. The effects were measured on Japanese-style bunkers and foxholes containing goats.

Chemical sampling equipment was installed, and troops landed at various times after the bombing in different types of anti-gas protection equipment.  The testing of mustard gas on volunteers took place on the mainland at Innisfail. This physiological research was to determine the effects of mustard vapour on the human body under tropical conditions.  Other tests conducted at Innisfail included the tolerance of man to dibutyl phthalate, which was used to suppress the vector of scrub typhus, and the effect of wearing anti-gas clothing on the ability of troops to perform normal duties and do heavy work in a tropical rain forest.  Details of the testing are summarised in the `Gillis Report', which was tabled in Federal Parliament on March 1987 by the then Minister for Defence.

There was no Army hospital at Woodstock. The 2/14 Army General Hospital was located in Townsville. During the mustard gas trials at Innisfail, a ward at Innisfail hospital was dedicated for use by the medical and scientific staff conducting the trials.  The ward was used from 1943 until the end of 1944 when the Field Experimental Station and the 1st Field Trials Company were moved to Proserpine.  Medical records or case histories were maintained on all volunteers, not all of whom were hospitalised.  Most, if not all, of these case histories are contained in `Chemical Warfare--Trials', Australian War Memorial Series 54, 179/5/7, Parts 1 to 10. These records were originally open for public access but in January 2023 they were shown as "Closed".

Personal medical records were maintained during the trials and would have formed part of the volunteer's medical record.  At the end of the war, the medical records of all ex-servicemen were sent to the then Repatriation Department in the State of enlistment of the member.

Brook Island was used for the aerial delivery of mustard vapour.  Hinchinbrook Island was not used for testing purposes, but was used occasionally as a staging area for personnel waiting to go to Brook Island to check the equipment after bombing had taken place. There is no evidence that Dunk Island was used for any military activities.



Cpl Patterson Charles Mills (75066) was a member of 6 Transportation and Movements Office RAAF during WW2. Whilst in Townsville, probably late 1942, Cpl Mills and a few RAAF and USAAF members were awoken early one morning and assembled on a deserted beach to the north of the city. They were given the mission of crewing a barge and delivering 44 gallon drums of unknown material to a small island. These drums weighed very little, appearing empty. To see them off there were some high ranking officers of both forces. The cargo was delivered to the island after about a 12 hour journey, and shortly after the return journey commenced, they ran out of fuel. Cpl Mills wondered whether this had been deliberate. They drifted for a number of days in the Coral Sea without a search for them being mounted. They were eventually picked up by the corvette HMAS Bowen. Upon their return, there was no one to meet them and they were split up. To this day Cpl Mills does not know what the mission was about, what the cargo was, or why the silence upon their return. He has often wondered if the drums contained gas. He also intrigued by the obvious importance of the mission's departure compared to the lack of concern for their non return after delivering their mysterious cargo.


Was this a delivery of drums to Brook Island perhaps, or somewhere else?


Can anyone help me with more information?


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This page first produced 5 December 1998

This page last updated 31 January 2023