Harrietsham Zero Station


Few people realise that Harrietsham played its part in the UK secret underground invasion plans of the Second World War. The story began in 1940 when Sir Winston Churchill gave orders for the construction of a ‘stay behind’ operational force and communications network to be used after the anticipated German invasion to hinder and disrupt the Nazi troops.

Very simple underground bunkers were constructed to accommodate specially trained resistance fighters. These were located at hundreds of secret sites around the coast of the UK. In addition, a network of underground communication centres were built, these larger more complex sites were equipped with VHF communications equipment operated by specially trained female ATS (Auxiliary Territorial Service) officers. One such site is located near the Ringlestone road between Hollingbourne and Harrietsham and was generally known at the time as the Harrietsham In Station or Zero Station.


The purpose of the station was to periodically receive information from 11 ‘out’ stations located around the coast of Kent. The information related to observations by a specially selected group of individuals who had agreed to spy on the Germans after the invasion. However, the aborted German invasion plans allowed the ‘spies’ to limit their observations to UK, American and Canadian troop movement and this was relayed back to the central control station at Reigate via Zero stations such as Harrietsham.

This map showing the final network plan was produced by Major R M A Jones on 28 June 1944




The Harrietsham ‘In’ station was provided with two or three specially built VHF communications transceivers. These battery powered units running from a 6 Volt car battery were known as TRD’s.

This sketch by Sally Walterhouse Brown shows Freddie working on one of the sets in the Harrietsham bunker.




Various ATS officers were posted to or involved with the Harrietsham station between 1942 and 1944 these included the following:
Elizabeth Rush, Airlie Abinda Campbell, Peggy ?, Hazel ?, Phyliss Marion Britten, Ely ?, Wendy Kaines, Marjorie Tarrant Edwina Burton, Sally Waterhouse-Brown, Margaret Hamilton Rigby, Florence Margaret Cole (Waddy), Senior Commander Beatrice Temple, Lieutenant Roy Russell
Sally Waterhouse-Brown was clearly a talented artist. While serving in the Harrietsham station she produced several coloured pencil drawings of her fellow officers. Fortunately these were donated to the Imperial War Museum as document 3150 by the estate of Margaret Hamilton Rigby and this is an excellent example which shows her explaining the electrical wiring to Phyllis Britten.


Although the subterranean bunker was equipped with beds and other equipment this was reserved for use after the anticipated invasion. Normally, the station operated from a small hut located very close to the dugout and the subalterns were billeted locally for meals and bedding. Usually the girls would stay with a local family. Perhaps even today there are stories in some families of well-spoken army girls who came to stay but who never talked of the work they were doing.
This sketch by PWB shows one of the beds inside the bunker where Airlie Abinda Compbell is noisily snoring.

The ATS subalterns were responsible for day-to-day station operation but equipment maintenance which included periodic battery replacement was carried out by ATS personnel attached to Royal Signals Units. Lieutenant Roy Russell of Auxiliary Unit Signals was the officer responsible for Harrietsham and also the sister station at Brasted.


This is a verbatim account written by Lieutenant Roy Russell, officer in charge of the Harrietsham station:

A Royal Engineer officer came – I think he was a captain – and took us to see our two underground units, ready for our occupation. The Royal Engineers had built the stations, and devised the secret entries. The unseen hatchway design was brilliant. You had to know exactly where to look, usually on the fringe of a copse with tall trees, where the camouflaged aerials were strung high. We put the radio equipment in and we started testing.

I did not see the In stations being built, but when they were operating I went in a lot, so I remember what they were like. The sets were the ones we had been developing, and our main task was to put up the aerials and their hidden feeder cables. The aerials were working on a very high frequency, not known to the Germans or the Italians. It meant that to get good communication the aerials had to be very high, over 100 feet. The aerials were made of two pieces of copper wire, and what we called a dipole – you sometimes see an aerial with two rods sticking out and a junction box which somebody told me Jack had made. From there it was joined to something I had never seen before -a co-axial cable; it was never used domestically then. The cable had to go up the main trunk of the tree. (The aerials at the Out stations were simple-no one would query a domestic type aerial) The cables were placed under the tree bark, which had to be peeled hack and then replaced.

To get into the underground station you had a crank (I had one and so did Jack) you knew more or less where the entrance was and you had to find a particular small flat stone. I don’t know where they got them from but there was one in each place. You moved that, and underneath you could see the rod which the crank fitted onto. You could turn it and up came a circular piece of grass which was really like a manhole cover which you see in the street, except that it was a large saucer-like piece of turf which had been cut to fit entirely into it so that when it was tightened you could not see any join. When it came up it revealed a shaft and at a certain height you swung it away so that you could climb underneath it. You then put the crank handle on the rod at the bottom of the turf and turned it the other way to reseal it and no one knew you were there except your colleagues. The structure was like a Nissen hut with corrugated iron arched across to form a roof.

The shaft was four sided, about the size of a trap-door. It was wood-lined; there was no ladder, but wooden steps, fastened at one side, and you just climbed down, about 8 feet, on to a concrete floor. At the bottom there was a room, about 6 feet by 9, with shelving all round, and on one shelf there was an empty shell magazine, which gave the impression, if anyone found it, that the place was an empty ammunition dump. If you looked carefully, on one of the shelves lay a length of rigid wire. If you knew what to look for, there was a small hole in the woodwork into which you could push the wire. Something was activated on the other side and the whole of that side cantilevered. If you bent down you could now walk in and close it behind you. You were now in a room where you would see in front of you two tables with our radio sets on and three ATS officers operating them. They were talking to the Out stations and when they were free they would talk to us, telling us of any military incidents, or it could be just a set problem or aerial trouble or a power problem, or it could be to do with air-conditioning or sanitation or battery charging .Usually we could sort it out; if not we would radio back to our base in Sevenoaks. I had a staff of twelve – they were of different trades – Jack was the only sergeant; there were one or two NCOs who had got their stripes by passing radio tests, so if anything went wrong I had the staff to deal with it. Then I would ask the ATS whether they had any other problems and if not we would have a cup of tea, and we would go back up the shaft the way we came. The main faults were usually with the aerials.

Communication at the high frequency we used required accurate direction for reliable reception. High winds or even branch growth could alter the delineation and lose radio contact. It would then be necessary for one of our several volunteers to go up the tree. He would be hauled up, standing in a noose of rope thrown over a high branch. The other end was attached to my Humber car, and by slowly backing, he would be drawn up the tree. Sometimes he had to climb the last few feet, carrying a bag of tools on his back. This was a job we shared in view of the risks involved. Even when we started winning the war, towards the end, we were still operating, as this was part of an anti-invasion operation, which Churchill personally set up because he said, and I remember his words, “The French were run over and had to start thinking about setting up a resistance.” I met Churchill just once. I was at a meeting where he spoke to me and others. He was very positive that we were not waiting till we had been invaded before we set up a resistance movement.

Those who passed information to the Out stations were never seen by me or my staff. Also in reserved occupations, they were trained in the recognition of German military vehicles and their uniforms. Their received information would be passed on to the other radio people without them knowing each other, so that if either was captured neither could be made to give the other away. This was because the metal numbers on some telegraph poles had been taken out and a space bored deep enough to take written messages. The trick was that the pole number would be replaced upside down to indicate that it was “live”. I believe that the info-gatherers were also trained in hand-weaponry, infighting and garrotting but I have no proof of this.

This was why the Out stations were set up. We knew at once if anything was wrong at the coastal stations because the first thing the In stations did (there were eight Out stations to one In station and nine to the other) was to call each station. The Out stations had very much less complicated sets than the In stations; theirs just said “Send” and “Receive”. They were designed by Jack Millie. (The aerials for the Out stations were also very simple-no one would query a domestic type aerial.) All those who worked at Out stations were volunteers.

Beyond the Set room there was a room with cooking facilities and Elsans, and there was a room for battery charging. There was no electricity laid on; everything was powered by batteries which had to be recharged by a little engine a ” Chorehorst” – (petrol-driven) in a tubular cage; the exhaust from that was led away by a duct and came out in a ditch some way away, where you could only just hear it faintly. The last room led to an emergency exit tunnel which was a heavy duty concrete culvert pipe, 30 inches in diameter, 15 – 20 feet long, through which the occupants could try to escape should their station be discovered by the enemy.

On paper we were known as a group called “Auxiliary Units” which would convey nothing of what our military role was. It was part of the Y service, another anonymous service.

The ATS officers — Captains – had not had any military training or drill and had not come up through the ranks. Recruitment happened when one of the girls went on leave and in chatting to a friend would drop hints about the secret work and tell her how she could apply. She would be told to go to Harrods in Knightsbridge, wearing a red rose. The store was boarded up, but the doorman would tell her to go to the fifth floor. Other girls wearing a red rose were there, and each would be interviewed by Senior Commander Beatrice Temple- a niece of the then Archbishop of Canterbury, William Temple. They were tested solely on their suitability for secret work. Only when they were accepted would she tell them what they were going to do! They were then kitted out and came straight to us. I said “Why are they officers? We could have done this with ATS sergeants” I was told “Well, we first thought all they needed to be was privates, and then we thought with all you chaps going down there it could have been very difficult “I don’t think so” I said “They never interested me”

That is why they were ATS officers. We all acted correctly. They were nicknamed “Secret Sweeties” (not by us!) which apparently they hated, but they knew they had to keep their mouths shut. And of course, they never wore trousers always skirts! They were very nice girls, cut-glass spoken! They were taken from the FANYS sometimes and other sources which could be trusted. Both In stations in Kent at Brasted and Harrietsham worked with Out stations which were virtually on the Kent and Channel coasts. When we started we were the only group operating; it was only when they found that the system worked that other stations were developed. Eventually there were fourteen areas around UK, each having its own In stations and Out stations.

I regularly visited my Out stations. One was in a farmer’s chicken coop; they had their own ways of deciding where to hide their sets. I said to the farmer “Where is your set?” We went out to the barn and inside one of the coops he lifted a board on a hinge. He had cut a space in the chalk ground underneath to fit in his set. In another coastal place the lady operator was a music teacher and her set was in the Music room. “Where?” I said “Can’t you see it?” she said. I was looking all round and I told her she had hidden it very well. She took the front off the upright piano; she had removed the top eighteen or twenty key hammers and it was there. These sets were designed by Jack Millie; they were in aluminium cases, about a foot long; they were robust and all they had was an on/off switch according to whether you were sending or receiving. If you wished to send, you might have to wait for the In station to come back to you; it was so simple a child could use it; Jack had kept it so simple. Another set I remember was operated by a vicar; I asked him where his set was and he took me into the church and showed me where it was in the pulpit. “Nobody but me goes up there!” I remember another Out station because the man did not want me to know about it; he said “You don’t need to know, do you?” but I said “Yes, I have to!” The set never went wrong so I never went back there again! It seems now that after our In stations were successful, others were built further inland as a second line of defence, and have now been discovered.

The girls at the In stations arranged the times of contact with Out stations according to the operators’ occupations. There were always three on duty at the In stations; they worked eight hours on and sixteen off all through the conflict. They never complained though the work was full time underground.

The time came that there was much speculation that we must soon be mounting a joint invasion of Northern France with the American forces, now building in Southern England. There was a much larger concentration in places like Salisbury Plain and the South Coast. Our tiny contribution, although I only guessed at the time, was to step up our on-air traffic. We made up hundreds of meaningless five-letter coded group messages and transmitted them to our Out stations for their “dummy traffic” responses; round the clock. It was the first intimation I had that the enemy could pick up our very-high-frequency; although maybe they couldn’t, we’ll never know. If they could it would tell them that our invasion could start from the Dover coastline. In support, a concentration of tanks, landing craft and military vehicles in our area could have been seen by their recce aircraft. It caused them to leave troops in the Pas de Calais that were not facing ours when D-day came. But they were life-size blow-up dummies, even realistic when I saw them at ground level; as bogus as our surge in radio traffic.

Current Situation
The bunker is located on private land and after 79 years has deteriorated considerably and must be considered at risk of collapse. The corrugated structure has rusted away therefore should not be walked over or entered.
At least one of the trees in which the VHF aerials were concealed is still standing and the cables that were once buried beneath the tree bark can be seen today.
Brian Drury 2020

Harrietsham Zero Station
Harrietsham Zero Station
Network Map
Network Map
Freddie At Work
Freddie At Work
Sally Waterhouse-Brown
Sally Waterhouse-Brown
Airlie Abinda Compbell
Airlie Abinda Compbell