The US Army Signals Corps built a radio transmitting station on many acres of land at 180 Youngs Road, Hemmant in Brisbane, Queensland in 1943. The transmitter building was a tee shaped building. There were some 100 feet high rhombic aerials erected by the Americans at the Hemmant site. The aerials have long gone, but the old transmitter building and diesel (250 kVA Buckeye) building still remain to this day. 

1st Lt Henry W. Flora was the Commanding Officer of the US Army Signal Corps Transmitting site at Hemmant in Brisbane from 26 February 1944 and then reassigned to Seaborne Communications at Bulimba on 23 September 1944.

Whilst Henry W. Flora was at Hemmant, the US Army Signal Corps operated a powerful Western Electric D-156000 twin channel single sideband transmitter linked to San Francisco as part of the Army Command and Administrative Network ACAN. There were a number of other Radio transmitters to SWPA bases and other theatres located at Hemmant. The one 10Kw transmitter may have been for Delhi, India. Whilst Henry was at Hemmant, the very powerful Press Wireless 40Kw amplifier that was used earlier in the war was no longer being used in 1944 for transmissions.

Channel A of the Western Electric D-156000 transmitter carried Sigsaly encrypted telephone conversations to San Francisco while channel B was used for sending automatically encrypted teletypewriter generated messages to the USA. This meant the Sigsaly secure voice communication signals for General Douglas MacArthur located in GHQ, SWPA in the AMP building were sent via Side A of the transmitter and six reliable encrypted Teletypewriter TTY circuits were sent simultaneously on channel B as per the diagram below. The TTY circuit went from Base Section Three Headquarters in Somerville House Girl’s School at South Brisbane and the Sigsaly circuit went from the AMP building to Hemmant via Base Section Three Headquarters at the School. Henry W. Flora told me that the audio input to the transmitter consists of two 3000kc kc channels prepositioned by HQ carrier terminal equipment. Channel A, is input to a modulator with a carrier frequency of 125kc its output goes through a 125.1 to 130kc filter. Channel B is fed the same carrier frequency and goes through a 130.1 to 135 kc filter. These are then combined and the signal is one sideband with a carrier frequency of 125kc. The sideband containing the audio information is 125.1kc to 130kc.


© Diagram drawn by Peter Dunn


Photo:- Henry W. Flora

The Western Electric 1K SSB Transmitter D-156000 at Hemmant


I received the following comments from 101 year old Henry W. Flora on 10 February 2020, a few days before his 102nd birthday:-

D15600 - That is a number I will never forget. It transmitted the hottest communication circuit in the South Pacific. Woe to the OIC who failed to keep it going. The final stage had two 10 x 4 in. Ceramic tubes upon which was wound heavy silver wire. The two tubes on the final stage were tuned synchronously by turning a knob on the front. As the knob was turned small metal wheels made contact with the wire on the tube to complete the circuit. The tuning confers were fixed. That’s another story. I think that roller/tube must been made to fail in an otherwise reliable transmitter. (Joking)

When I arrived Hemmant late Feb 1944 there was no spare. On maintenance down times at 4 am in the morning we would clean the silver wire on the tube.

One time the roller failed while operating to San Fran. It seemed like seconds that two Colonels were there from HQ to harass me. My men and I were a good team without them no operations. We soon had the transmitter operating and I avoided the brig. My motto for me to be a good officer “Treat your men right and and they will do The job”


Photo:- Henry W. Flora - July 1944

Looking the opposite direction to the doors that opened at the end
 of the Tee. 10 KW Press Wireless transmitting to Delhi on the left.


Photo:- Henry W. Flora - July 1944

Looking toward the door to the living quarters. Henry W.
Flora's cubby hole with cot was just beyond the doors


Photo:- Henry W. Flora

Left to Right:- Warrant Officer Clark, 1st Lt. Henry W. Flora, and 1st Lt. Murray Hannah


Photo:- via Leo Maloney

Photo of the original buildings as they looked probably in the 1950's


Photo:- via Leo Maloney

View of the main Transmitter Station building probably in the 1950's.
Note how it was originally raised above the surrounding swampy ground


Photo:- via Leo Maloney

The generator building can be seen past the end of the main Transmitter Station
building. They are probably PMG vehicles parked near the generator building.


Photo:- via Leo Maloney

Close-up of the main Transmitter Station building


Photo:- via Leo Maloney

Fuel drums can be seen beside the generator building.
The external bulk diesel fuel tank can just be seen
below the window at right of the building in the photo.


Photo:- via Leo Maloney

An aerial can be seen in the swampy surroundings


The Transmitter Site main building in recent times at 180 Youngs Road, Hemmant


Side view of main building showing the tee part at the rear of the building (on the right)


Note the old timber construction barbed wire security fence around the buildings


Generator Building at Hemmant Transmitter Site


The inside of the Generator building


Photo:- 1st Lt. Henry W. Flora

Lt. Jay Thornehill standing beside the large
250 kVA Buckeye Generator in 1944


Henry W. Flora sent me the above photo of the 250 kVA Buckeye generator that was used at Hemmant during WWII. He said to note all the poles on the stator which allowed the low speed of the Buckeye generator to generate at 60 hertz at low speed. Henry told me:- "I started it once a week to check it was ready for use. With the compressed air start it was a sweet sound. Chug ———-Chug. —— Chug. — Chug - Chug, Chug, Chug at a low speed."

Lionel Sharp who worked at the Hemmant site after the war can remember a gap in the floor of about 1 - 2 inches between the cement block that the engine was mounted on and the normal cement floor. The engine was started by a giant compressed air bottle which would have been located near where the above photo was taken.

Lionel Sharp remembers a walkway along the side of the Buckeye generator along which you could walk (about 3 feet off the ground) and squirt oil onto the rocker arms from an oil can. Lionel said that the Buckeye Diesel was pulled out of Hemmant and installed at the PMG's Bulimba workshops. This then meant there was no emergency plant at Hemmant! For many many years after the war, diesel fuel was ordered by the PMG and delivered to Hemmant and duly recorded and "booked out" as it was used. Every year there was an annual accounting of fuel delivered against fuel used. Many many years later it was discovered the the dip stick was calibrated in US gallons!!!. 1000 Aussie gallons equals 1200 US gallons. There was much confusion as to how this had gone on for years and not been detected. At this time the Australian Broadcasting Commission was closing its Alice Street Studios in Brisbane and their emergency power plant was a 30 kVA (Lionel thought) power plant which was powered by a Southern Cross Diesel was surplus, so it went to Hemmant to replace the old Buckeye Diesel.

Lionel Sharp said that when the original Buckeye 250 kVA generator was removed, you could see the names of three persons and the year "1943" etched into the concrete slab. The three men were as follows:-

Sgt. B.E. Norris
Sgt. H.V. Fowler
Sgt. R.J. Krotky


The names in the concrete slab
inside the Generator Building


The men all slept in an open area to the left as you entered the front door of the main building. A small kitchen was located near the door. 1st Lt. Henry W. Flora's place to sleep was on a cot (camp bed) in a small open door room next to operations. Everyone who went into operations passed through Henry's "bedroom". Maintenance down time as agreed with San Francisco was from 4 am to 6 am. Most of the time Henry either participated in or directed the maintenance or repair. They then went on to the frequency prearranged with San Francisco. Holding their breath, "come in San Francisco", and there was great relief when contact was made.

Henry shared the following with me on 11 Feb 2020:-

"Due to the small detachment we were on Diem to have a one meal a day paid for by the army. We took turns at going to the Wynnum pub. Other meals we did mostly prepared by ourselves in the small kitchen at Hemmant."

"Hemmant personal were assigned to the 997 Signal Service Co, 832 Signal Service Bn. Per my 201 File. I was assigned to Hemmant Feb 26, 1944 to Seaborne on 23 Sep 1944 and to the Manila land station probably Sep 1944."

"Receiving Station North of San Francisco would tell Hemmant that the SSB signal was fading and tell Hemmant to go to a specific frequency and they would look for Hemmant on that frequency. I do not remember any event longer than when we held our breath to hear SF say “Come in Brisbane”. The preset frequencies selected were between 5 and 21 meg hz. Day time higher frequencies, night lower."


Photo:- Henry W. Flora

The Cafe / corner store at Wynnum where the men from
the Hemmant Transmitting site would eat their meals.


1st Lt. Henry W. Flora's men liked Australian beef and on one occasion they stocked up and they had beef in my different ways from then on. Since their small detachment had no mess facilities they were on per diem daily allowance and ate one meal a day at a small cafe in Wynnum (see photo above).

Their truck is parked outside the Cafe in the photo above. Henry told me:- "We made ourselves famous (or not wanted) by eating the nasturtium flowers on the table. Fish and Chips was my favorite. Everyone was very friendly to us which we appreciated."

Henry told me about an incident which occurred outside the Cafe one day as follows:- "If the press of today would have been there what follows would be an international incident in that relations between the U.S. and AUSTRALIA were strained by a standoff incident. Once as we came out of the Pub, lo and behold there was a woman behind the wheel of our truck! I went to the truck and asked her what she was doing and to please get out. I noted with alarm that the keys were in the truck and with further alarm noted that she was drunk! I continued to talk to her while I cozied closer to the truck. Suddenly I reached in and grabbed the keys. The international incident wound to an end by some friends of hers persuading her that if she remained there she would become a hostage of these Yanks."


Photo:- Henry W. Flora

Left to right:- Mark, Corporal Blake, Private Ryan,
Technical Sergeant Sich, and 1st Lt. Henry W. Flora sitting
on a bench across the road from the beach at Wynnum


During their regular visits to Wynnum for meals, 1st Lt. Henry W. Flora remembers at low tide watching "hundreds of small crabs come up and skitter all around".

Henry W. Flora told me a story about their food disposal arrangements at the Hemmant site as follows:- "Not far from the front door underground was a large concrete square tank that had a trap door at ground level. It was were all kitchen waste was stored. At one time it became full. Even before I planned to have a lottery on who would clean it out, one of my technicians, Sergeant Sanders volunteered to clean it. I wasted no time accepting his offer."

1st Lt. Henry W. Flora was transferred to Seaborne Communications on 24 September 1944, and was in charge of two specially installed transmitting ships which they fitted out at Bulimba on the Brisbane River. His transfer papers show that he was relieved from the 997th Signal Service Battalion to the 3rd 40-KW Radio Station Section (Fixed), 3169th Signal Service Battalion.

Henry's first glimpse of his Seaborne assignment was of two Ocean Lighters OLs of which he was Office in Charge. Seven Ocean Lighters had been acquired during April/May 1944. At that time they were no longer marine ships as all marine gear had been removed. They were essentially for housing of Radio Transmitters. There was just open space below deck. Their job was to install new 40K and D156000 SSB Transmitters plus other smaller Transmitters. Hemmant continued to operate. They were in effect to be a floating version of Hemmant. In addition there were two other O.L.s that were to have Receiving equipment installed under the supervision of 1st Lt. Murray Hannah. Henry said that it was indeed a challenging job to make such an installation in an iron cage. All cables were covered with lead. All equipment had to be anchored to the deck. Work went on night and day under lights. Dipole antennas were installed regardless of proper impedance matching. When Radio operating the masts were extended to twice there heights. On 1 November 1944, with a complete and operable installation, they moved on to Hollandia to align with the moving of General Douglas MacArthur's Headquarters there.

In addition to the O.L. Numbers assigned they simply referred to the ships as T1, T2 and R1, R2. T1 contained the 40K and SSB. T2 contained the Motor Generators. The T boats were towed in tandem by a Navy Tug to Hollandia, likewise the R boats. There was only one Army person on each boat. Henry called for volunteers. The ships had no amenities. The rest of the men went by troop ship to Hollandia. 1st Lt. Murray Hannah and Henry were the only Army people to stay with the Weeroona, their accommodation ship and its Australian crew. The Weeroona stopped briefly at Milne Bay on the way to Hollandia.

On 27 February 1945, PCE 849 entered Manila Bay carrying 25 tons of signal equipment including 2 1/2 ton transmitters for radiotelephone channels intended to reach Brisbane and San Francisco. On 18 March 1945, the Grand Fleet of Ocean Lighters arrived in Manila Harbour with its complete ACAN installation. There was a Signal Centre complete with tape relay equipment and Antrac or radio relay. The radio relay equipment was used for communications between the various barges. There were two 50 kilowatt generators per barge with each adapted for salt water cooling. Within 48 hours of arriving in Manila Harbour, Henry W. Flora and his men had the large SSB transmitters operational, thus allowing communications from General Douglas MacArthur's GHQ SWPA at Manila to San Francisco using a land based rhombic antenna. The SSBs also provided a radiotelephone service (Sigsaly) to both the USA and Brisbane.

On 14 February 2018, 99 year old former 1st Lt Henry W. Flora, dusted off his Crowley TRF Receiver that he bought in the 1920's and last used in 1930. With assistance from his son Bob Flora, they connected power and an antenna to the Crosley on 16 February 2018, Henry's 100th birthday, and when Henry put on the ear phones, he immediately heard a voice without touching any of the tuning controls.


Photo:- Henry W. Flora 16 Feb 2018

1st Lt. Henry W. Flora on his 100th birthday, 16 Feb 2018
operating his Crosley TRF Receiver for the first time since 1930.


Photo:- Henry W. Flora 16 Feb 2018

Henry W. Flora's sons, Bob, & Steve, found this
tube in the back pocket of an old pair of army
chinos pants. They mounted it and presented it to
1st Lt. Henry W. Flora on his 100th birthday.


Old Commonwealth of Australia sign on the end of the main building.


The US Army Signals Corps site at Hemmant worked in conjunction with a Receiving Site about 5 - 6 miles away at Capalaba which was established in 1943 at Cotton's Farm, Capalaba. Lionel Sharp mentioned that a George S. Barr used to work for the Americans at the Hemmant transmitting site. Roy McIlwain told me that an American, John Pollitt also worked at the Transmitter site and used to live at Wynnum West.

Christopher McIlwain mentioned that at one stage they dug up a very large multi-core cable in the paddock.


Concrete slab at the Transmitter site (possibly not a WW2 slab)


There was a Press brand Wireless Shifter Unit at the Hemmant site, which converted teletype signals into radio signals. This then drove 1,000 watt Federal brand transmitter type BC339K. This transmitter then drove a 10,000 watt Colonial brand amplifier. 

It is understood that the purpose of the US Army Signal Corps WW2 radio system was to maintain direct contact with Washington via San Francisco.

Messages were apparently relayed directly by teletype link to General Douglas MacArthur's GHQ, SWPA in the AMP building in Queens Street, Brisbane.

Ken Osterberg of Detachment 3 of the 832nd Signal Service Company, advised that part of Detachment 3 was the men who operated the overseas radio station in Brisbane. It's possible they are the men who ran this site and the one at Capalaba.


There is a line of smaller slabs running up diagonally away to the right from the above larger slab.
These smaller ones are possibly WW2 slabs for the rhombic aerials


One of the smaller slabs


Another old slab with a more modern steel base anchored to it


via George E. Boileau, Jr.

Pass for Corporal G.E. Boileau (14063483) to access the Hemmant Transmitting Station


via George E. Boileau, Jr.

Corporal G.E. Boileau was living at Camp Yeronga


via George E. Boileau, Jr.



hemmantts15.jpg (114251 bytes)
via George E. Boileau, Jr.

Calendar for part of 1943 and all of 1944


Photo : via George E. Boileau, Jr.


The Hemmant Transmitting site was used after WWII by the Commonwealth of Australia as a Radio Station. The Hemmant site was sold a number of years ago to a former Lord Mayor of Brisbane, Clem Jones. It has since been resold and converted into a private residence which is owned by Ian and Roslyn McIlwain. The Generator Building is now used as a storage building.

Michael O'Leary was the sole PMG radio technician at the Hemmant Radio Station in the early 1970s. Michael has written a short history of his involvement at the Hemmant Radio Station. Michael told me that there was an old cot (camp bed) still at the Hemmant site when he was there, which was probably the one used by 1st Lt. Henry W. Flora.



On 23 December 2017, I received an e-mail from 99 year old Henry W. Flora, the former Commanding Officer of the Hemmant Transmitting Station. Henry has generously shared some of his photos and his memories of his time at Hemmant and with Seaborne communications. Henry went on to tell me that he has continued to keep in regular contact with his buddy, 100 year old Murray Hannah, the former Commanding Officer of the Seaborne Receiving Station built on an Ocean Lighter at Bulimba on the Brisbane River. Henry went on to become the Commanding Officer of its companion Seaborne Transmitting Station.

I'd like to thank Lionel Sharp for his assistance with this home page. Lionel worked at both the Hemmant and Capalaba sites back in the 1950's and has provided much of the above technical information. They were both "one man" stations when Lionel worked there.

I'd like to thank Christopher McIlwain (Ian's son) and Roy McIlwain (Ian's brother) for their assistance with this home page.

I'd like to thank George E. Boileau, Jr. of Gilbert, Arizona USA, for his assistance with this web page. His father George Edward Boileau, Sr. worked at the Hemmant Transmitting Station during WW2. George died in 1987 and is buried in New Orleans, Louisiana USA in the family tomb.

I'd like to thank Laurie Murray, Gary Ryan, Michael O'Leary and Leo Maloney for their assistance with this web site.


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This page first produced 9 May 2003

This page last updated 11 February 2020