Cracking the Enigma code

The “Bombe” code breaking machine was built in Letchworth, but those working on it had no idea what they were building, or what the eventual significance would be. The Bombe, designed by Alan Turing and built by the then British Tabulating Machine Co (later ICL) was used to crack the Enigma Cipher.

I worked at the British Tabulating Company in Icknield Way during the war years. I worked there from 1941 to 1945, in the section known as the Engineers Department. They were taking on people, and the area expanded from the ground floor. A long room was built above this and ran parallel with Cromwell Road on the end of the building. Upwards of 100 girls worked there on benches doing wiring work.

Some made cables on frames. My own work was putting connecting wires on to drums, which on the opposite side had rows of wire brushes, and girls had to make sure these were lying flat and level to make a good connection, as they spun round on the “Bombe”.

I recall we were rushed down to the air-raid shelter when the siren went on one occasion, apparently Lord Haw-Haw had threatened the Letchworth area from some attention by the Luftwaffe! But that was the only time I remember that happened.

Mr Simisfer was the manager of the whole section, including the men on the shop floor. Mr Archer was one charge hand; we had a forewoman called Rene, but I don’t recall her surname.

We used to have long singsong sessions to cure the boredom, when we each chose our favourite song, that took a while to go through. This used to annoy the men downstairs so much that they used to send Jack Darge, their foreman, a Scot, to complain. He used to live at Stotfold.

I lived at Clifton, Beds during the war and the works buses ran early morning, and after work finished, if you missed them, you had to get home by way of Hitchin.

Until the book, ‘The Ultra Secret’ was published in the seventies we really had no idea what it was we made. We very often had groups of service personnel come and had a look round; the Navy, Army and Americans later on.

People from Bletchley (the boffins) also visited downstairs where the complete Bombe was built. But of course we had no idea who they were or where they were from. There was always some tension about when they were expected.

As soon as the Germans signed for peace we ceased production, all the wiring charts and information was collected up to be destroyed.

The Labour Exchange (that was in those days) were given rooms to interview workers in, and they decided where to direct the person onto their next jobs. I was sent to the Cosmos factory at Bondor at Baldock. They were making valves and radar equipment.

In June 1942 while working as a Capstan Lathe operator at the BTM factory in Icknield Way, I and three colleagues were instructed to report to Vauxhall Motors Luton immediately, to be trained as automatic lathe setters. At the time I had recently registered and was expecting to be called up for military service very soon. The training course was scheduled to last three months but in fact we were recalled to Letchworth after only a couple of weeks to start production at No. 5 Factory. This was a basement under the Government Training Centre in Pixmore Avenue Letchworth. When we arrived there were only two machines installed and we started work on these while squads of soldiers and sailors rolled in and bedded down more machines daily. This was before the days of forklift trucks and machine tools had to be manhandled and rolled in on round steel bars. The basement was very basic, and most of the plumbing and electrical work was carried out around us while we were working. No conduit was available so electricity cables were just clamped to the walls and ceiling. EMTAC (Emergency Machine Tool Assistance Corps.) came in to continue our very sketchy training and for the first few days our tea break caterers were squaddies, who told us that the machine tools they were bringing in had been commandeered at the docks, as and when they arrived from America. Eventually our full complement of 23 autos were installed as were all the lathes, milling, drilling, grinding, Capstan machines, etc. A canteen was provided
We worked alternate day and night, 12 hour shifts, six and seven shifts each week. We were issued with security passes which had our photographs on them, most unusual in those days, and we were supposed to hand them in when the factory closed down in 1945, but I have seen two recently which were kept as souvenirs.
Foremen and setters were all men, mostly locals and had been transferred from the main factory; some like myself were upgraded from other jobs. A couple were former printers who had been retrained at the Government Training Centre. Operators were all female who had been directed into essential war work They came from two main areas, either Lowestoft or Hastings, and were billeted either with Letchworth families or in the huts at Woodlands Lodge in Baldock. The total workforce was about 120 on each shift.

In 1945 about three years after opening, the factory was shut down, the girls went home and I along with others of a similar age group received our call up papers for the forces.

Strange as it may seem neither I, nor anyone else, on the shop floor, were aware of what the piece parts we were making were really for. We were under the impression that the final product was something important for the Admiralty but we did not know what. It was not until the 1970s when honours were awarded to senior members of the firm that we realised we had been involved in such important work; that we had in fact been making parts for ‘Bombes’ – the British answer to the German ‘Enigma’ machine. The machines we made were used at Bletchley Park, Station X as it became known.

Winston Churchill said that this was the best-kept secret of the war and had been responsible for saving the lives of many Allied Servicemen and had shortened the war by many years.

extract from “Letchworth Reflections” – memories of Letchworth 1960 to 2003