Saving Bletchley Park

by Sue Black

  The panel were a great group of people who were obviously very passionate about the pioneers and about making sure that we chose the right people. After preliminary welcomes and introductions we got stuck straight in. We were told that the aim was to find a set of five pioneers that we were all happy with, and that the shortlist we had been given was not prescriptive but suggestive. A discussion commenced. When it came to the appropriate point in the discussion I said that I thought we should choose Ada Lovelace over Charles Babbage. It was quite a difficult argument to make, especially as at that point in time not that many people knew about Ada Lovelace and her contribution, whereas everyone had heard of Charles Babbage. But, fortunately, the rest of the panel listened to my reasoning and agreed that we should include Ada Lovelace.

  I then spoke up for Tommy Flowers, who I also felt should be included. The panel, however, felt that we must include Alan Turing, and that to have two people from Bletchley Park would seem a bit skewed. I could see their point and demurred.

  After a very long and lively discussion, our final list was as follows: Ada Lovelace, Alan Turing, Hedy Lamarr, Sir Tim Berners-Lee and Sir Clive Sinclair. We were interviewed about our choices and I said the following about the women that we had chosen:

  “I am delighted that BCS is highlighting and celebrating key Information Pioneers and am particularly glad that these two great women Ada Lovelace and Hedy Lamarr have been chosen. These great films show us that women have made really fundamental contributions throughout history, let’s make sure that we encourage and support women to continue playing a key role in this exciting area.”

  and about Alan Turing:

  “Not only did Turing play a key role in the code breaking work carried out at Bletchley Park during World War Two, he also made fundamental and insightful contributions to computer science and elsewhere. Last year’s very welcome government apology highlighted his lasting contribution and acknowledged his persecution and abhorrent treatment as a consequence of being gay, at a time when homosexuality was illegal. Honouring Turing as an Information Pioneer gives us a chance to celebrate Turing’s life and legacy and promote him as a role model for information pioneers of the future.”

  I was happy that even though I hadn’t completely got my way and managed to get Tommy Flowers included, I had managed to make sure that everyone on the panel now knew about Tommy – and we had 40 per cent representation from women!

  A few weeks later I was invited one evening to a preview screening of the films near Goodge Street underground station. Five short films had been made with five celebrities, one for each pioneer; I couldn’t wait to see them.

  I met up with Kelsey, who had come down from Bletchley for the evening, and we went in together. Luckily I knew quite a few people there as I had been involved with the BCS for some time and I’d also been on the judging panel. After picking up some drinks we circulated and chatted to various people. I introduced Kelsey to anyone that I thought might be useful to Bletchley Park. I felt that my role was to be like a warm up act for Kelsey or Simon whenever we were together at events. I would start or move a discussion to the topic of Bletchley Park, say what an amazing place it was, ask if had they visited, then introduce Simon or Kelsey to take the discussion further as they saw fit. It was an arrangement that worked well.

  Kelsey Griffin and me at the Information Pioneers film preview After a while it was time for the film previews, so we all trickled into the small cinema and took our seats. I sat with Kelsey behind Ortis Deley from The Gadget Show and Kate Russell from Click, two of the film stars. We watched the five films in succession: Ortis Deley spoke about Ada Lovelace, Kate Russell about Alan Turing, Miranda Raison about Hedy Lamarr, Phil Tufnell about Sir Tim Berners-Lee and Dom Joly about Sir Clive Sinclair.

  James Thellusson from Glasshouse, who had spearheaded the initiative for the BCS, gave a short talk about the process, the panel and the films and then the lights were dimmed and the films began. They were all very good – entertaining, well written and interestingly presented and put together. I felt very proud to have played a small role in making them happen. When all five films had played we had a general discussion, with the director and writer answering questions about who had been chosen and why. It was very clear that everyone had really enjoyed the films and that they were excited to see what the public thought of them. It was a great evening.

  With Ortis Deley and Sarah Blow from GirlGeekDinners Shortly afterwards the films were put up online, and featured in the media, and the public were asked to vote on their favourite over a period of a few weeks. The voting vacillated between the different pioneers during the voting period, but in the end there could only be one winner . . . who do you think it was? Who is the greatest information pioneer ever? It’s a tough question to answer. (In case you’re still wondering . . . the winner was Alan Turing.)

  Initiatives such as BCS Information Pioneers may be seen as fluffy in comparison with the roles that these groundbreaking scientists played in our history. But I believe that this type of initiative, which gets information across in a way that is palatable and entertaining to the general public, is a great way to honour our pioneers. It is an important role of both traditional and social media to present important information in a way that helps us all to understand our history. Alan Turing, Ada Lovelace, Hedy Lamarr, Clive Sinclair and Tim Berners-Lee have all made important contributions to the world of technology, and campaigns such as the BCS Information Pioneers serve to help us all understand and be inspired by these contributions.

  You can still see the films on the BCS Information Pioneers page:

  http://pioneers.bcs.org/

  18

  Colossus, Tutte and Flowers

  “At the time I had no thought or knowledge of computers in the modern sense, and had never heard the term used except to describe somebody who did calculations.”

  —Tommy Flowers

  In November 1941, Bletchley Park experienced something of a panic.

  The cause, as unlikely as it sounds, was a new detective novel called N or M, written by the world’s greatest crime novelist, Agatha Christie. In the book, her plucky heroes, Tommy and Tuppence, are on the trail of Nazi spies working inside Britain. That in itself was hardly a problem for the staff of Station X. However, when this paragraph appeared at the end of Chapter 1, all kinds of alarms went off:

  “I always introduce my guests,” said Mrs Perenna, beaming determinedly at the suspicious glares of five people. “This is our new arrival, Mr Meadowes – Mrs O’Rourke.” A terrifying mountain of a woman with beady eyes and a moustache gave him a beaming smile. “Major Bletchley.” Major Bletchley eyed Tommy appraisingly and made a stiff inclination of the head.

  Mention of the name Bletchley in a book about spies was just too worrying a coincidence. To make matters worse, it was known that Christie was friends with Dilly Knox. MI5 immediately opened an investigation and sent agents to see Knox, suspecting that someone had perhaps been talking a little too openly about the work going on at BP. However, Knox was convinced that this was not the case and agreed to sound her out. He therefore invited Christie to his home in Naphill in Buckinghamshire and, over tea and scones, asked why she had named her character Major Bletchley. She replied, “Bletchley? My dear, I was stuck there on my way by train from Oxford to London and took revenge by giving the name to one of my least loveable characters.”[44]

  This event happened at a time when Knox’s cancer had started to take a serious toll on his health. When Christie visited him he was already so frail that he’d been forced to spend most of his time working at home with only very occasional trips to BP. He was never to see the allied victory he’d so brilliantly supported as the cruel disease finally claimed his life in February 1943. Knox’s passing marked the end of an era for code breaking, an era that had relied heavily on linguistics, intuition and knowledge of human behaviour in which Dilly Knox and codebreakers like John Heri
vel excelled. Not that such work stopped; there were still plenty of the “old school” achieving extraordinary results and his colleague Peter Twinn took over the day-to-day management of the team, now known as ISK or “Intelligence Services Knox”.

  By 1943 the computer age had arrived. It was in answer to the hugely increased traffic in coded messages – far too many for pencil and paper-based “breaking machines”. The most important ciphers that need to be cracked at this time were those used by the German High Command to relay messages between Hitler in Berlin and his commanders in the field. “We knew nothing about this cipher machine; the Germans had kept it completely secret,” explains Tony Sale. “We first began to intercept radio transmissions in 1940. It was actually a group of policemen on the South Coast of England; they were listening for German agents’ transmissions from within the UK – of course there weren’t any as we’d captured all the agents – but they heard these weird signals and they sent them to Bletchley Park.”

  This was the fiendishly complex Lorenz cipher, generated by a machine attached to a teleprinter that cleverly used the teleprinter’s binary language to produce a complex code. The codebreakers referred to these machines as “Fish”. Individual models were then given specific fish-related names such as “Sturgeon’ (the Seimens & Halske T52) and “Codfish” (the NoMo1). The Lorenz SZ40 and 42 models were codenamed “Tunny” and the places identified as transmission and receiving sites for Tunny messages were also given fishy names e.g. Bream (messages sent between Berlin and Rome), Mullet (between Berlin and Oslo) etc. Because Lorenz was so complex – it used twelve wheels compared to Enigma’s three – it quickly became the High Command’s cipher of choice. It therefore became paramount that the code be broken as soon as possible.

  Efforts to break the Lorenz cipher using traditional methods were eventually successful, largely due to the efforts of three codebreakers: Brigadier John Tiltman, Major Ralph Tester and Cambridge graduate Bill Tutte. It was Tiltman who first recognised the importance of these messages and that they were coded using a letter substitution process known as the Vernam System. This fact became apparent after a German operator made a big mistake. On 31st August 1941, the operator sent two versions of the same message without resetting the machine in between. Because both were sent using the same key, it enabled comparison and analysis, which led Tiltman to the fact that Vernam was involved. A section was set up at BP, headed up by Tester and which became known as “The Testery”, to work on breaking the system. But it was Bill Tutte, working meticulously through pages and pages of squared graph paper, writing out line after line of characters, who found the answer. Using a technique called Kasiski Examination, he built up a huge matrix of letters in which he could spot repetitions of sequences of characters that were more common than could be accounted for by chance alone. Over the course of several months, Tutte spent every working hour adding to the matrix – some of his colleagues even accused him of slacking off work to “fiddle with letters” – until, one day, the system revealed itself and the codebreakers could now crack the Lorenz cipher. To put Tutte’s extraordinary feat into perspective: it’s been calculated that without his efforts, it would have taken an operator 500,000,000,000 years to crack a message coded using Lorenz. As the result of his dogged perseverance and professionalism, that time was reduced to just four hours. It has rightly been called one of the greatest intellectual feats of World War II.

  The Testery carried on attacking Tunny for the next twelve months and broke over 1.5 million coded messages. From mid-1943 onwards, the Testery is credited with breaking over 90 per cent of Tunny traffic and saving thousands of lives. For example, they were able to warn the Russians of the impending German assault on the city of Kursk allowing the Russians to prepare. The resulting tank battle – one of the largest in history – was a decisive victory for the Russians and has been called the turning point in their war. It would have been a very different story had the Germans retained the element of surprise.

  Ralph Tester, Captain Jerry Roberts, Major Denis Oswald and Captain Peter Ericsson headed up a team that eventually employed nine cryptanalysts, 24 ATS[45] and a total staff of 118. However, even if they had taken on hundreds of extra staff, it would have been impossible for the Testery to keep up with the volume of intercepts and translations. Just as Turing had done with Enigma and the Bombe machines, the decoding of Lorenz needed to be mechanised. The man to whom this problem was passed was Professor Max Newman, a mathematician from Cambridge University. Taking Bill Tutte’s findings on board, Newman and his team in “The Newmanry” began designing an automated version of Tutte’s graph paper method, comparing ciphertext and key to look for departures from randomness.

  The first machine they designed was nicknamed the “Heath Robinson” by its Wren operators due to its rather thrown-together arrangement of wheels and belts looking remarkably like one of the famous illustrator’s gadgets.[46] Construction began in January 1943 and the first prototype was operating by June. Newman, Donald Michie, two engineers and sixteen Wrens kept the machine going. However, the machine was still too slow and the messages were piling up. Plus, having to run two punched paper tapes in unison at 1,000 characters per second meant that the tapes snapped, and the machines frequently broke down or got out of sync.

  It was at this point that Alan Turing, who was aware of a brilliant engineer called Tommy Flowers who had done some sterling work in improving electronic telephone switchboard systems with thermionic valves, suggested that he be brought into BP to examine the problem. Flowers was a radical thinker, although he was in admiration of people like Turing who seemed to operate on a different, higher level to everyone else. He once said in a lecture, “You’d be working on a problem and not able to solve it, and sometimes someone would look over your shoulder and say ‘Have you tried doing it like this?’ and you’d think ‘Of course, that’s how you do it!’. With Turing, he’d say ‘Have you tried doing it this way?’ and you’d know that in a hundred years you would never have thought of doing it that way.”

  Flowers examined the problems with the Heath Robinsons and concluded that there was nothing that could be done to improve them or to decrease the amount of times they malfunctioned. He therefore suggested that maybe a new, different approach was needed. He suggested that the clunky, frequently malfunctioning, mechanical switching units used by the Heath Robinsons be replaced by valves. The valves could also act as memory storage, meaning that only one punched tape would be needed. At first his suggestion was met with scepticism by the codebreakers but he eventually persuaded them that it would work. However, time was against him; Flowers’ estimate that a valve-based computer would take a year to build was simply unfeasible; in a war of this complexity and magnitude, the entire direction of the conflict could change in days, let alone a year. The decision was taken to “make do” with the Heath Robinsons and more were built.

  But Flowers wasn’t ready to give up on his idea yet. He returned to his laboratory and workshops at Dollis Hill in London and set to work. Ten months later, he and his team had built the prototype of his new type of machine. Weighing in at over a ton and filling most of a room, it was quickly dubbed Colossus. And, on the 8th December 1943, the machine was transported to Station X, set up and demonstrated to the codebreakers for the first time.

  Colossus was a huge leap forward; it could run through the millions of possible settings for the code wheels on an enciphered teleprinter, such as Lorenz, at a staggering 5,000 characters a second – slow to us now but mind-blowing back then, and five times faster than the Heath Robinsons could ever hope to manage. The codebreakers immediately set about testing its accuracy and reliability. It passed on both counts, test after test after test.

  Colossus would go on to make a huge impact in decoding enemy messages, but Flowers didn’t sit back on his laurels. Having proven the worth of his concept, he was then asked to build a MKII Colossus with 2,500 valves rather than the 1,500 used in the MKI. He
was also challenged to build it before June 1944. Although he wasn’t immediately told what it was needed for, Flowers delivered on time and Colossus MKII, which ran even faster than the MKI, was tested and operational by June 1st. Just a few days later, the need for it became apparent when D-Day happened. The messages deciphered by the Colossus MKII proved beyond a doubt that the deception campaign designed by the War Office to throw Hitler off the scent had worked. It meant that the Normandy landings – or Operation Neptune – could go ahead as the Nazis had kept their Panzer tank divisions in Belgium, expecting a landing there.

  By the end of the war, 10 MKIIs were operating at full capacity and 63 million characters of high-grade German messages had been decrypted.[47] Like the Bombes before them, much of the day-to-day operational work on both the Heath Robinsons and Colossi was done by women. “There were 1,500 wireless valves or more in each machine,” recalls Lorna Fitch. “They looked a bit like light bulbs and the heat was terrific.” But, at the close of hostilities, most of the Colossus machines were dismantled and the plans for them destroyed. Only two machines were retained and were moved firstly to Eastcote in West London to the first home of what became GCHQ and then to its current home in Cheltenham, Gloucestershire. One of the machines remained operational until 1960; it’s been suggested that it was used to decode Russian traffic during the Cold War as the Soviets undoubtedly captured many of the Nazi’s Enigma and Fish machines. It’s generally felt among historians that the Russians were the reason that Churchill had everything destroyed when BP was run down.

  Tommy Flowers recalls the day in 1960 when he was contacted to destroy the last two remaining Colossus machines: “That was a terrible mistake,” he says. “I was instructed to destroy all the records, which I did. I took all the drawings and the plans and all the information about Colossus on paper and put it in the boiler fire. And saw it burn.”