Ann Williamson was one of a very few female mathematicians in the country at that time. When she’d said at school that she wanted to specialise in that area her headmistress had told her she couldn’t because ‘mathematics is not a ladylike subject’. Fortunately, Ann’s parents overruled the headmistress and eventually Ann earned a place reading mathematics at Lady Margaret Hall, Oxford.
‘When I went up to Oxford in 1940, there were five women in the whole university who were reading maths that year. We were very scarce.’
After completing her degree, the Oxford University appointments board sent Ann and Hilary Brett-Smith, another of the five female maths graduates, to interviews at Bletchley Park and a few weeks later they received letters from the Foreign Office appointing them as temporary assistants at a salary of £150 a year and telling them to report to Bletchley. Hilary joined Hut 8; Ann went into the new female Machine Room.
‘We had to go through the Watch to get to the Machine Room and just by the door connecting the two was a table with pieces of paper laid out on which people in the Watch had written some of the jumbled nonsense that came through the air waves and then underneath they’d written what they thought it might be saying in German. We would pick up one of these pieces of paper and make a menu, connecting these letters we received to the letters they should have been saying. I loved that work making menus. It was very like doing crosswords, joining a chain of letters.’
The menus were sent through to the Wrens coordinating the work that the various Bombe outstations would carry out via a Lamson pressurised air communications system. The menu was put into a canister which was then inserted into a tube connecting the Machine Room with the Bombe Control Room. A partial vacuum in the tube system drew the canister in and routed it through to the Bombe Control Room. Ann and the other girls called it the ‘spit and suck’ because the pressurised air system sucked the capsule in and ‘spat it out’ at the other end.
‘The Wrens working on the Bombes would set them up and then telephone us when they got a stop, which would be the position at which the Bombe stopped where all the chains on your menu were accurate.’
The women in the Machine Room then set up an Enigma machine with the right rotors and settings thrown up by the Bombe and typed in the letters of the message to see if the letters lighting up on top of the Enigma machine produced German text. If they did, then the settings would be passed through to the Decoding Room where the women set up their modified Typex machines and typed out all the messages from that particular German network. Ann and her fellow female codebreakers had a far more interesting job than any of the women in Hut 6 had enjoyed before.
‘The most important code for us was the Red. There were ten or so of us working in the Machine Room. It sounds much more complicated than we found it at the time. It was fascinating, all these messages coming out in German. I loved it.’
The expansion of the whole process into what was effectively a factory production line, impossible without the increased numbers the women provided, was essential if the codebreakers were to keep track of German troops during the invasion of Europe, but by now Bletchley had broken a code that was even more complex. The messages they decoded would tell Allied commanders precisely what Hitler and his generals planned to do next.
All the main front-line command posts were linked to Hitler’s command posts in Berlin and Rastenberg in Poland by teleprinter links on which the messages were automatically encoded by the Lorenz SZ40 device. There was an SZ40 between the teleprinter and the transmitter and another at the other end between the receiver and the teleprinter. The operator at one end simply typed the German message in, the SZ40 encrypted it, and the transmitter sent out the encoded message. At the other end the encoded message passed through another SZ40 which decoded it, and the message then typed up automatically in plain German text on another teleprinter.
The codebreakers gave the Lorenz system the codename Tunny, after the fish more commonly known as tuna. Each of the teleprinter links between Hitler and the various generals on the front line was given the name of a different fish. The two most important ones for British commanders were between Hitler and the German commander in France, Field Marshal Gerd von Rundstedt, which Bletchley codenamed Jellyfish, and the link between Hitler and Field Marshal Albert Kesselring, the German commander in Italy, which they called Bream.
The Lorenz SZ40 had twelve wheels, ten to encipher the message (paired in two separate rows of five) and two drive wheels. The movement of the second row of wheels was highly complex, making it difficult to break. But in 1942, in an extraordinary piece of codebreaking, John Tiltman and Bill Tutte, a recently recruited chemistry and mathematics graduate, did just that and two new sections were set up to work on it.
The first section, run by Max Newman and called the Newmanry, worked out how the first row of wheels were set and how they rotated. The second section, led by Ralph Tester and called the Testery, used the stream of letters produced by the Newmanry to work out the action of the second set of wheels and decode the actual messages.
Newman, who had been Alan Turing’s tutor at Cambridge, realised that the work in his section could be done much faster by the sort of ‘computing machinery’ that his former student had already envisaged building. This didn’t yet exist. It was just a series of ideas in Turing’s mind. But Newman put his ideas to the head post office research engineer Tommy Flowers and explained precisely what the ‘computing machinery’ needed to do. By the end of 1943 Mr Flowers and his team had produced Colossus, the world’s first electronic digital computer, an astonishing, ground-breaking achievement that, because of the secrecy surrounding the work of the codebreakers, would go unrecognised for decades. Colossus did not break the messages. This still had to be done by hand. But it made the process of working out the settings of the first row of wheels far quicker.
The encoded German teleprinter messages were intercepted at Knockholt, near Sevenoaks in Kent, and printed out on perforated paper teleprinter tape. The tape of the messages was run through Colossus, which read it electronically and worked out the wheel settings and the way in which the wheels moved. It needed two people to operate it, quite aside from the codebreakers who were working out how it should be operated. Given the success of using the Wrens to operate the Bombe machines, it was no surprise that they turned to them to operate Colossus.
Marigold Philips was born in Etwall, near Derby, to members of what was then known as the ‘County Set’. Her father was the managing director of a Manchester warehousing company and while the family had no aristocratic links they regarded themselves, and were regarded locally, as country gentry.
‘If you owned property you were somebody in those days. We lived in a medium-sized country house where the horses and dogs were much more interesting than the people. I was the odd one out in that I wanted to think and have ideas whereas most young female members of the country gentry just wanted a rich husband and more horses.’
Although Marigold regarded her mother and father as good parents, it was not a very close relationship. While children were not regarded as being as low down in the scale of importance as servants, they were certainly kept out of the way most of the time, minded by nursemaids when they weren’t being taught to read and write by their nanny or later given more extensive education by a governess.
‘Children were something you had that lived somewhere else in the house and were expected to grow up and conform. We weren’t the apple of anyone’s eye. Children were children. Speak when you’re spoken to. Live your own life in the nursery. I had a nanny and then a governess before I went away to school, which I was longing to do.’
Marigold went to Downe House School at Cold Ash in Berkshire as a boarder. It was a very good school and at the time emphasised the need for ‘low living and high thinking’ – a total change from what she was used to at home.
‘It’s now seen as very trendy, but it was then seen as a very intellectual school. We were serious-minded, gen
tly feminist and expected to have careers.’
During the school holidays, Marigold’s mother made sure she and her sister were tightly chaperoned. They were only allowed to go out with young men if the cook went with them, so they became quite adroit at getting round the restrictions.
‘It was terribly easy. You dropped the cook off at the nearest pub, gave her some money for a drink and picked her up on the way back. But the interesting twist is that in those days at sixteen or seventeen we didn’t really know what we were being chaperoned for, because we didn’t know what the hidden dangers with young men were.’
It wasn’t until she went up to Oxford to read English Literature at Somerville College, then an all-women college, that she learned the facts of life.
‘I was sexually ignorant and a young don’s wife put me right on certain things. She was appalled to find that I didn’t know. This was typical of young girls from our privileged but fairly un-intellectual background.’
When she finished her ‘wartime degree’, restricted to two years so the students could leave and contribute to the war effort, Marigold’s mother told her to join the Wrens. It was an entirely pragmatic social decision and, despite having been to university, Marigold was still not twenty-one and so was given no choice.
‘My mother thought it was time I came off my intellectual high horse and the Wrens were thought to be where young ladies were more likely to meet suitable husbands, i.e. naval officers, heaven help us.’
After three weeks at Mill Hill scrubbing floors to make sure she was willing to follow orders, Marigold was interviewed and asked if she liked crossword puzzles – she didn’t. How about maths? She insisted she was hopeless at it. They didn’t seem to care. She was sent first to Eastcote for a period of induction into the world of codebreaking and then, in August 1943, to Bletchley to work in the Newmanry.
‘I realised subsequently that they didn’t give a damn about what your qualifications were, if you were a nice young girl from a decent family you were not likely to rat on them.’
Dorothy du Boisson, a 23-year-old from Edmonton, north London, arrived a couple of months before Marigold and was given a talk by Max Newman on what the work involved.
‘Mr Newman was a very quiet man, reserved and not at ease with girls. He walked up and down in front of us with his eyes on the ground, talking about a machine with twelve wheels. When he had gone we were none the wiser. Later we discovered that he thought we had been told what the section did. Mr Newman decreed that everyone, except himself, be called by their first name. This was a wonderful idea. At once we were a team.’
Maggie Broughton-Thompson, an eighteen-year-old vicar’s daughter from Little Aston in Staffordshire, joined the Wrens straight from school. She’d been due to go to Mill Hill to do her basic training but a doodlebug had hit it, putting it briefly out of action, and she was sent instead to Tullichewan Castle.
‘I got the impression practically everyone in my draft was already earmarked to go to Bletchley because we certainly had no choice and we had no particular interview or anything. We were just told we were all going to the same place and they couldn’t tell us where it was or anything about it because we simply weren’t allowed to know. So that was it.’
Maggie worked as a registrar in the Newmanry’s Registry Office where the messages coming in from Knockholt printed out on perforated paper teleprinter tape and were prepared for use on Colossus. Two identical tapes would be spliced together with glue, using a heated clamp, to make a loop which would run through the computer repeatedly.
‘The messages were transferred in duplicate. You had to first of all make sure that there were no mistakes, that the two tapes were identical, and then however long or short the message was, the two ends were spliced together in a machine that sort of stamped them together so that they didn’t come apart.’
There were two Wren registrars working in the Registry Office, keeping a record of every tape that came in, the time that it was run through Colossus, how long the run took and where exactly every tape was located after being run.
Jean Thompson was just nineteen when she was posted to Bletchley in 1944 to work on Colossus; she spent most of her time working on the computer itself. Two Wrens would operate the machine under the direction of a duty officer, one of the codebreakers, all of whom were male.
‘If the pattern of the wheels was already known you put that up at the back of the machine on a pinboard. The pins were bronze, brass or copper with two feet and there were double holes the whole way down the board for cross or dot impulses to put up the wheel pattern. Then you put the paper tape on round the wheels with a join in it so it formed a complete circle.’
The number of wheels used depended on how long the tape was. The tape was placed behind the computer’s photo-electric cell and held secure by a clip, then the movable pulley wheels were adjusted to make sure the tape was taut.
‘At the front there were switches and plugs. After you’d set the thing you could do a letter count with the switches. You would make the runs for the different wheels to get the scores out, which would print out on the electro-matic typewriter. We were looking for a score above the random, and one that was sufficiently good you’d hope was the correct setting. When it got tricky, the duty officer would suggest different runs to do.’
Marigold worked in both the Registry Office and on Colossus, which generated a lot of heat and smelled of hot oil. It was a mindless task that didn’t require either mathematics or an intellect. They had to log every tape and how long it had taken to run the job.
‘It was very hot and we wore our blouses with the sleeves rolled up. But we were young and it was the war. We didn’t give a stuff about that sort of thing.’
They also knew that they were doing something very valuable to the war effort. Mr Newman held regular briefings for the Wrens to make sure they knew the importance of doing the work as quickly as possible and that they were actually having an effect on the war.
‘He had the imagination to realise that young people would work better if they were kept informed – which we were, amazingly – of some of the effects of what our spying had led to – because it was a form of spying. Once a fortnight, he would give us a résumé of what was happening.’
Perhaps most surprising of all, given the tight security at Bletchley, with no one allowed to know what other sections at the Park were doing, Mr Newman didn’t restrict himself to the successes produced by the breaking of the Newmanry and the Testery, even talking about the successes resulting from Hut 8’s breaking of the naval Enigma.
‘He told us at Christmas 1943 about the sinking of the Scharnhorst being directly related to Bletchley. I’ll always remember being told about this, also from time to time about the sinking of German U-boats. We were given quite specific information but I don’t think there was any thought that we would disclose it. He would talk to us and trust us. He was a rather remarkable person and he treated us with great respect even though we were just doing this rather mindless task as we saw it.’
They were billeted in Woburn Abbey. Marigold’s ‘cabin’ was in one of a number of wooden huts in the parkland around the house.
‘They were called cabins because we had to speak navy talk all the time. We went in through the front door where there was a very fierce woman called the regulating officer, a terrifying blonde lady.’
Maggie slept in the old maids’ quarters in the attic along with a number of other girls from the Newmanry. They were squeezed into double bunks which had wire-mesh bases that you could feel through the very thin mattress.
‘It was bitterly cold in winter and diabolically hot in summer. They could just about fit in four double-decker bunks so there were eight of us squashed in, with very little space. We all worked on the same watch, which was essential. If you had night watches, you were asleep during the day – you couldn’t have people rushing in and out. We all got on very well together. The cabin became our little social group.’
There were four watches, A, B, C and D, working round the clock. When Marigold first arrived in the late summer of 1943, before the arrival of Colossus, there were just seventeen Wrens in the Newmanry. By mid-1944, with one Colossus computer up and running and several more on the way, there were eighty-six Wrens there with around twenty on each watch. A week of nights was followed by a week of evening shifts, then a week of days and then a week when the members of the watch filled in on other shifts and had the weekend off, during which they would go home or take trips to London.
Marigold used to go to London to meet up with friends from Oxford, all of whom seemed to have had more of their wits about them. They hadn’t been pushed by their mothers into the Wrens and were now doing ‘interesting things’ at the Foreign Office.
‘We would go in twos and threes to the theatre or to have dinner with some sad brother or boyfriend, which was the height of glamour. Of course, we fancied men like mad but there was a definite cut-off point. We were told very early on, in my mother’s words, “no man will marry a girl who is shop-soiled”, a horrible image, but it worked. Most of us were virgins when we married.’
The trips involved quick-change operations from Marigold’s naval uniform at the next station on from Bletchley on the slow train to London.
‘I clearly remember getting out in my Wren uniform with a little bag, going into the cowshed, changing my clothes and putting my uniform in the manger, then catching the next train up to London in my glad-rags. When we got back we would change back into our uniform, roll up the evening dress and stuff it in something and arrive back at work as a Wren.’
They weren’t allowed to stay away overnight; if they had, they would have been deemed to be ‘adrift’, another uniquely naval expression, in this case for being absent without leave, and they would have been hauled before the regulating officer.
The Debs of Bletchley Park and Other Stories Page 17