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First-Hand:Bletchley Park, Station X - Memories of a Colossus Operator

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Bletchley Park, Station X - Memories of a Colossus Operator

Submitted by Eleanor Ireland

In the Spring of 1944 I was working in London and at this time one of my friends joined the WRNS as an MT Driver, which possibly influenced my decision to do the same. So in great trepidation I took myself off to Queen Anne's Gate and volunteered. I was interviewed there and then and very soon called to a medical. It was not long after that I received a letter telling me to report to a WRNS establishment at Tulliechewan Castle near Glasgow on 2 August 1944.

Strangely enough the week before I was due to set off on this adventure I met another school friend and talking to her found that she was also joining the WRNS and had been asked to report to the same place at the same time. We found out much later that instead of reporting to Mill Hill, which was usual, as there had been a spate of bombing in London they did not wish to take any chances over the new intake and sent us up to Scotland. I was very pleased to think that I had a companion to go with, and as it turned out we were to stay together until we were demobbed at the end of December 1946 and are still close friends.

We travelled to Glasgow and then out to a small station on the edge of Loch Lomond where we were picked up and taken to Tulliechewan WRNS reception camp, which was a requisitioned castle -a large estate on the side of the hill. At the bottom of the hill was the Regulating Office, a large number of nissen huts - sleeping quarters, a mess and stores hut etc - and opposite an enormous parade ground. Up at the top of the hill was the castle, used by the officers, and another parade ground with the Naval flag.

A bell sounded at 5 a.m. to get us up, after which we had to do various menial tasks, cleaning out the huts, potato peeling , blancoing the steps of the castle, etc - all dedicated to putting us off.

Some people left at this stage. Those that were left were kitted out with temporary garb and eventually with our uniform, which took some time, and were given our service numbers which one never forgets - they seem to be engraved on your soul!

We did hours of squad drill to smarten us up and were lectured on the Senior Service and its history since the time of Pepys. We were interviewed to find out what category we would like to go into. I cannot remember what I said but a friend of mine distinctly remembers saying she would like to go into signals. This we found out very much later was all a terrific blind as they had already decided where we were going. Just before we departed we were told hat we were being posted to a station 50 miles from London in the country - very depressing we thought.

Going down on the night train from Glasgow, which was absolutely packed with Service personnel, we arrived at Bletchley completely exhausted. From the station we were taken by transport to Bletchley Park only a few minutes away. The transport stopped at a very high security-fenced entrance manned by security guards and we were taken, a few at a time, into a concrete building where we were issued with a security pass and ordered to guard these with our lives. Without this pass we would be unable to enter the compound.

Before us was a large Victorian mansion with a sward of grass in front of it. A Wren officer escorted us into a low building adjacent to the mansion, where she gave us a very intimidating lecture about the extreme secrecy of both the place Bletchley Park and every aspect of the work which was done there.

We were never to divulge any information about our work; the place where we worked; never to discuss our work when outside, not even with those with whom we worked; we were not to ask anyone else on the site outside of our own unit what they did; and were not to keep diaries. Our category we were told was PV Special Duties X. We would wear no category badges and if anyone asked us what we did we were to say we were writers and did secretarial work. We would get no posting anywhere else as the work was too secret for us to be released.

Everyone had to sign a document, The Official Secrets Act, and we were told that if we divulged any information gained about our work we would be sent to prison, at least. So effective was this talk that when we left the building where we worked we just dropped a shutter and blanked it all out.

Very bemused and subdued by all this secrecy we returned to the transport with still no idea where we were going. The transport drove out of the sleepy town of Bletchley for nine miles into the country, through woodland, until we came to the village of Woburn, where we turned up by the church and drove through a very imposing set of gates, through beautiful park land, until we saw in front of us the magnificent stately home of Woburn Abbey.

The transport stopped at the main entrance where we were met by a WRNS Petty Officer and taken into an enormous hall which had been made into a Regulatory Office. There we were issued with Station Passes for the Abbey and told that every time we went out our passes must be handed in and picked up again when we came back, except when we came back at midnight from the Evening Watch, when we would find them in our own labelled post boxes - a huge rack of cubby holes on the opposite side of the hal l. After climbing up the grand staircase to the second floor we were allocated to temporary accommodation.

All the off-duty Wrens were very helpful and showed us everything that we would need. I can still remember being very impressed by a:! the doub Ie green baize doors. The rooms were very grand since they were formerly bedrooms used by the family. The loos were of Delft china and raised two steps above the floor. The walls were lined with red silk. The bathrooms were also very impressive, very large and again the bath was on a 'throne' two steps above the floor, encased in mahogany and very gloomy.

One of the first things I was told was that the corridor was haunted by a nun. This was told to me with great relish by a girl whose name was Dawn who assured me that her friend had actually seen her!

After we finished our fortnight'S initiation at Bletchley we were allocated to Watches, A, B, C or D, Fortunately I was put on the same watch as four friends I had already made -C watch . We were then moved up into a room under the eaves at the front of the house, the servants quarters, where eight of us shared a 'cabin' called 'Swordfish 50'. The cabin was spartan - four bunk beds, four chests of drawers and a built-in cupboard where we kept our cases, food etc, until we found there were resident mice!

Being up under the eaves it was very hot in summer and cold in winter. With eight of us we had to have the windows open, and when snow drifted in onto the window sill it would stay there for about three weeks. Bedfordshire is supposed to be the coldest county in England. Whilst I am on the subject of the Abbey our sitting room, or Fo'c's'le (Naval term) was the Grand double cube room - the largest and grandest room in the house. The walls were completely boarded up when we were there, and around the room at various intervals were a set of three electric metal tubes, four feet long, and around these tubes we sat grouped for warmth with our great coats on when we were off duty.

Later on they converted a pleasant square room with a marble fireplace, next door to our cabin, and joy of joys in the winter a fire was lit for us. We were provided with sofas with pretty cretonne covers and this was the nearest thing to comfort we came on throughout our career in the WRNS.

Our mess was the original kitchen down at the further end of a ground floor passage paved with stone flags worn down with age. We ate off scrubbed tables, and we all kept our own mugs in preference to the issued metal mugs. The food was just about edible.

All the buildings had been commandeered by the WRNS and the Foreign Office had the stables at the rear of the buildings - also hush hush. The Duke of Bedford was fearful that fire might destroy the building, so if we were not on duty we had to take it in turns, two at a time, to patrol the building in the dark for two hours at a time with torches. I hated doing this as it was all very eerie.

The Duke lived in a house in the grounds and he would come and have a look around every now and then to make sure everything was all right. All the family pictures and furniture were stored away in another wing of the Abbey. Some of my friends had a lovely cabin on the ground floor which I recognised when I went back many years later. It is now a dining room, hung with yellow silk and a magnificent collection of Canaletto paintings of Venice.

The park was magnificent, with seven lakes and several herds of rare deer. I loved the view from our cabin window.

There were very few officers at the Abbey, and none of them, not even the Officer in Charge, had any idea of the work that we did. I can remember that when we first went there, if we had a Sunday off watch, we were expected to join the Church Parade and march two miles to the Woburn village church and back. Later on the First Officer was warned that we were under terrific pressure at work and told not to stress us unnecessarily, and latterly I do not remember going to church and discipline became more relaxed.

The day after we arrived at the Abbey we were driven into Bletchley Park in an old army transport bus with a soldier at the wheel. The bus stopped at the main gate and we all got out and showed our passes, being then told to wait outside the mansion house. From there we were escorted past a tennis court, past some very hideous low concrete buildings on either side of a drive to Block F, another concrete building. They were all very grim and as we later on learned bomb proof.

At the entrance to Block F we were met by Max Newman, who introduced himself and welcomed us. We were taken into a long low room with a very large blackboard and long tables.

Max Newman stood in front of the blackboard and we all sat at the tables. He was a Professor from Cambridge, a mathematician. He had a very pleasant manner and put us at our ease. He told us that this was a fairly new section which had been recently set up and that we would be working with mathematicians and engineers. He had specifically asked for Wrens to man the section, run the machines and organise the Registry Office.

For a fortnight we went in every day and he lectured us on a new type of binary maths which he would write up on the blackboard. We were shown the tapes that were used on the machines that we were to become familiar with. We had to learn the alphabet punched on the tapes and become adept at reading them. The tapes were one inch wide and very strong and the alphabet the same as the GPO teleprinter alphabet. On either side of each sprocket hole there was space for two holes to be punched above and three below so that, for instance, A was two holes above the sprocket and nothing below. On the Colossus machine these sprocket holes went past an electronic eye at 5,000 per second, so that 5,000 letters registered per second.

We were taken round the Section and shown what everyone was doing. We were shown the room where the messages came in on teleprinter tape on two separate machines. Most of the messages came from Knockholt and Kedleston in Derbyshire as I learnt later. We were shown two Colossus computing machines they had at that time - Mark I. I thought they were quite incredible quite fantastic. I was completely overawed by them, a mass of switches, valves and whirring tape. We were shown into a very long room where tapes were cut and joined, and tapes that had split on the machines were repaired. Then we went to Ops or Registry itself where all tapes were registered and tabulated and put into a series of cubby holes.

There was a room called the Tunny room where the Tunny machines received the tapes from Colossus and decrypted the text. This could be done on Colossus, but Colossus was considered too valuable as an analytical machine to spend time doing this.

At the end of the fortnight we were tested on our knowledge and depending how well we performed were sent to various tasks - in administration, dealing with the tapes as they came in, etc. I was delighted to be put on Colossus, whic h I considered was the plum job! I was taught by a Wren called Jean Bradridge how to operate the machine, what all the switches were for, and how to peg a wheel pattern on the grid at the bac k of the machine with pins that looked like very large, very strong hairpins, copper nickel plated.

The tape was shut into position in front of the photo electric cell, which had its own small gate for the tape to slide through to keep it in place. According to the length of the tape one used as many wheel as were necessary to make the tape completely taut. This was a triCky operation, getting the tape at the right tension. It took a little time and had to be done with great care - this was rather hair-raising. We were terrified of the tape breaking if the tension was wrong and valuable time might then be lost.

I can remember when I was given a new Wren to instruct I was worried about leaving her for very long, so when it came to our meal break I would hurry back to make sure nothing awful had happened. All the 'break ins' we put on were timed and they generally took about one hour to run. Every single tape was logged on and off in a book - the time we received the tape and the time it was taken off the machine. It was instilled into us that time was of the very essence. We knew we were working against the clock and that the lives of people depended on it.

Another big block was put up with two more Colossus. These were the improved and much larger Mark II version. I was sent to work on Colossus 3 and my friend Jean Beech was on Colossus 4. These were housed in an enormous room. They had 2,500 valves instead of the 1,500 on Colossus Mark I and in fact were twice as big and five times as fast - 25,000 characters per second were read. Later Block H was built to house ten more machines.

Jean and I worked by ourselves with a mathematician codebreaker, or 'cryptographer' as they were generally called. He would sit at a long table facing Colossus under thick meshed windows - all very spartan. These mathematicians came mainly from Oxford or Cambridge. Some came straight from University and some were a little older. The only name I can remember of those with whom I worked is Sandy Green. Others would come in such as Jack Good, Donald Michie, Shaun Wylie, to discuss what was going on and make suggestions.

On the tables in front of them were sheets of codes and they used slide rulers to make their calculations. Whoever we were working with would tell us what they wanted from the machine.

We would pin up on the grid at the back of the machine whatever they were working on and put on the tape they wished to run against it. At the front of the Colossus were switches and plugs.

We could set switches to make letter counts - how many E's, A's, S's etc were on a tape. The machine had its own electronic typewriter and would record all this. Sometimes we were given a norm and as each figure came up on the typewriter one calculated and wrote down against it how much above or below the norm the figure just typed out was, I became very good at mental arithmetic.

What was pegged up at the back of the machine were Lorenz wheel patterns and the tape on the wheels was an intercepted message tape. The purpose of Colossus was to find out what the positions of the code wheels were at the beginning of a message, and it did that by trying all the possible combinations , of which there were billions.

What I did not know then, and only learnt fifty years later, was that Colossus was designed to break the messages sent out by a machine called the Lorenz machine, which had been especially ordered by the German High Command to enable them to communicate in complete secrecy. The Lorenz machine was used by Hitler, Goering and Goebbels, also the Field Marshals and Generals. The machine that can be seen at Bletchley Park Museum actually belonged to Field Marshal Kesselring. The teleprinter signals using Lorenz were first heard in 1940 by a group of policemen on the south coast who were listening out for possible spy transmissions from inside the U. K. The Germans thought that the code sent out on the Lorenz machines was completely unbreakable.

By the beginning of 1942 Bill Tutte and other members of the Research Section worked out the complete logical structure of the Lorenz machine - a marvelious achievement.

In 1942, as I have learnt since from his son, Max Newman was approached when he was at St John's College to leave Cambridge and work at Bletchley. He carried forward the process of automation that had already been started and was introduced to the genius Tommy Flowers, a Post Office engineer, who designed Colossus.

When we were working on Colossus if anything went wrong with the machine we would contact the maintenance team. The Officer in Charge of the team was an extraordinarily clever man, quite brilliant, called Harry Fensom. He has given me his account of what happened when he joined the team at the G.P.O. Engineering Research Station at Dollis Hill which shows how the whole process of automation evolved. This is what Harry Fensom says:

"I started at Dollis Hill GP.O. Engineering Branch Station in August 1942 to work on constructing an electronic 4th wheel deciphering device for ENIGMA. I then went on to help construct a machine called TUNNY for simulating or modelling the LORENZ (Fish or Schlusselzusatz). All of these machines were invented or designed by Tommy Flowers and the circuit designs were by his right-hand men, Sydney Broadhurst and Bill Chandler. I was a member of a team of about ten who worked under these two and did some of the construction, but mostly the testing and helping to make them actually work.

Soon however about five of us were diverted onto the construction of a cipher breaking machine for the Lorenz in the Newmanry, called Heath Robinson, in collaboration with TRE (Telecomme Research Establishment) of Malvern. I went with Syd Broadhurst to Bletchley Park to install this machine and stayed for a while to help their personnel (including Donald Michie and Jack Good) to run it. Heath Robinson was the forerunner of the Colossus Mark I. I was recalled to Dollis Hill and there helped to get this Colossus to work. When it was running properly we dismantled it and shipped it to Bletchley, Syd Broadhurst putting me in charge of its installation there. Again I stayed there with a few others to keep it running and to clear any faults as they developed.

Meanwhile Tommy Flowers had designed an upgrade called Colossus Mark II which was about twice as big and five times as fast (25,000 characters per second reading the message). It also incorporated new facilities for various programmes which were different from the original specification.

So I went back and forth between Bletchley Park and Dollis Hill until it was finished and finally just before D -Day we had it running at Bletchley Park. Henceforth I stayed there as Officer in Charge of the maintenance and upgrade team until the end of the war. After the war I stayed at Dollis Hill and went on to design 'Ernie'."

Another brilliant engineer working with us was Ken Myers, who after the war worked on the coordination of all the London traffic lights. These engineers, as far as I know, have had little or no recognition of the magnificent work they did, which I think is most unjust.

I must mention Dr Thomas Flowers, the genius behind Colossus, who I am pleased to say did get some recognition for his work and was awarded the M.B.E. before he died a few years ago, Tommy Flowers' main contribution was to propose that the wheel patterns be generated electronically in ring circuits, thus doing away with one paper tape instead of the two that were run together before. He knew that valves were reliable as long as they were never switched off.

No body believed him but it was so.

According to Dr Flowers they started Colossus I in March 1943. They worked day and night, six and a half days a week for twelve hours at a time to have the Colossus installed in Block F in Newmanry Section by Christmas 1943. It was operational by January 1944 and successful on its first test against a real encrypted Lorenz message tape. It was vital to have it running before D-Day.

To return to the more mundane aspects of life, we worked on watches - A, B, C and 0 watches.

A and C interchanged and so did Band D. I was on C watch. We worked 9 a.m. to 4 p.m., 4 p.m. to 12 p.m., and 12 p.m. toS a.m. A week of days, a week of evenings, a week of nights and a week of changeovers. The fourth week we filled in any gaps in A watch. The changeover week could be very tiring - off at 9 a.m. and on again at 4 p.m. for instance. We had a weekend off every month and an occasional additional weekend.

We went to and from Bletchley Park in small buses. These would all be lined up on the drive opposite the mansion - besides going to Woburn Abbey some went to Gayhurst Manor, Wavendon and other destinations.

There were Foreign Office, Naval, Army and Air Force personnel at the Park but we never knew what was done in other sections. When we first arrived we ate in the mansion with the Foreign Office personnel and the food was good, but when there became too many of us they built some huts near our block and we ate there. The food was fairly grim. We found it difficult to eat on Night Watch - we never became used to eating then so would often walk out of the gate down a side alley to Bletchley Station. At the end of one of the platforms was a NAAFI hut and we would eat buns and drink a decent cup of tea before walking back - better than cold liver and prunes - I did not eat another prune for over thirty years!

At the end of the German War Churchill sent out an edict that all the machines must be dismantled and so we helped to break up Colossus. We thought this was very sad. Two machines went to Eastcote in North London and were eventually sent to Government Communications Headquarters at Cheltenham and dismantled in 1960. All the drawings of Colossus were burnt and its very existence kept secret.

We all had to sign the Official Secrets Act again and we all remained completely silent. When we meet, as we do in recent years every September, we all agree that those were our finest hours.

Further Reading

Eleanor Ireland Oral History