Celebrating Colossus and Tommy Flowers

Celebrating Colossus and Tommy Flowers

History is a fickle judge. In spite of colossal achievements, some are consigned to the dustbin of history due to circumstances which are not under their control. Tommy Flowers and his creation, the Colossus was one of them. He built the world’s first ‘programmable digital computer’ and helped save millions of lives and reduce the World War II by 2 years. Considerable achievement by any standards. Worthy of fame, recognition and riches. Only, in Flowers case his achievements were not even acknowledged for the better part of 30 years because it was classified information and worse still was attributed to others. Recognition came almost as an afterthought at the beginning of a new century, when his invention was re-built in 2004. Some recognition after all, is better than nothing.  Let us look at the extra-ordinary story of Colussus and its creator.

It was Alan Turing, the subject of our earlier article, Alan Turing – Father of Computer Science, who brought Tommy Flowers to Bletchley Park. Let’s look at the events as they unfolded from the article Colossus: Breaking the German ‘Tunny’ Code at Bletchley Park. An Illustrated History, by Jack Copeland. Compulsory reading for anyone interested in the history of Colossus.

“Turing, working on Enigma, had approached Dollis Hill to build a relay-based decoding machine to operate in conjunction with the Bombe (the Bombe itself was also relay-based). Once the Bombe had uncovered the Enigma settings used to encrypt a particular message, these settings were to be transferred to the machine requisitioned by Turing, which would automatically decipher the message and print out the German plain text. Dollis Hill sent Flowers to Bletchley Park. He would soon become one of the great figures of World War II code breaking. In the end, the machine Flowers built for Turing was not used, but Turing was impressed with Flowers, who began thinking about an electronic Bombe, although he did not get far. When the teleprinter group at Dollis Hill ran into difficulties with the design of the Heath Robinson’s combining unit, Turing suggested that Flowers be called in. (Flowers was head of the switching group at Dollis Hill, located in the same building as the teleprinter group.) Flowers and his switching group improved the design of the combining unit and manufactured it.”

We know now that Turing recommended Flowers for working on the Heath Robinson (the precursor to Colossus, and electronic code breaking calculator which was based on electromechanical relays and electronic valves). He recommended the senior engineer Flowers to none other than his former lecturer and fellow code breaker at Bletchley Park, Max Newan. According to Jack Copeland’s article in the Rutherford Journal,

“Max H. A. Newman (1897–1984) was a leading topologist as well as a pioneer of electronic digital computing. A Fellow of St John’s College, Cambridge, from 1923, Newman lectured Turing on mathematical logic in 1935, launching Turing on the research that led to the ‘universal Turing machine’, the abstract universal stored-program computer described in Turing’s 1936 paper ‘On Computable Numbers’.

At the end of August 1942 Newman left Cambridge for Bletchley Park, joining the Research Section and entering the fight against Tunny. In 1943 Newman became head of a new Tunny-breaking section known simply as the Newmanry, home first to the experimental ‘Heath Robinson’ machine and subsequently to Colossus. By April 1945 there were ten Colossi working round the clock in the Newmanry.”

Newman led the code-breaking effort against the “Tunny” What is this “Tunny”?

According to wikipedia, “…..Intelligence information revealed that the Germans called the wireless teleprinter transmission systems “Sägefisch” (sawfish). This led the British to call encrypted German teleprinter traffic “Fish”, and the unknown machine and its intercepted messages “Tunny” (tunafish).

Cryptanalysis of the Lorenz cipher was the process that enabled the British to read high-level German army messages during World War II. The British Government Code and Cypher School (GC&CS) at Bletchley Park decrypted many communications between the Oberkommando der Wehrmacht (OKW, German High Command) in Berlin and their army commands throughout occupied Europe, some of which were signed “Adolf Hitler, Führer”. These were intercepted non-Morse radio transmissions that had been enciphered by the Lorenz SZ teleprinter rotor stream cipher attachments. Decrypts of this traffic became an important source of “Ultra” intelligence, which contributed significantly to Allied victory.”

Apparently, Colossus was not the first machine designed to break the Tunny code. It was the Heath Robinson. According to Jack Copeland’s article in the Rutherford Journal,

“Heath Robinson worked, proving in a single stroke that Newman’s idea of attacking Tunny by machine was worth its salt and that Tutte’s method succeeded in practice. However, Heath Robinson suffered from ‘intolerable handicaps’.

Despite the high speed of the electronic counters, Heath Robinson was not really fast enough for the codebreakers’ requirements, taking several hours to elucidate a single message. Moreover, the counters were not fully reliable—Heath Robinson was prone to deliver different results if set the same problem twice. Mistakes made in hand-punching the two tapes were another fertile source of error, the long chi-tape being especially difficult to prepare.”

Enter Tommy Flowers. Colossus was built and the British code-breakers never looked back. Jack Copeland in his article observes, claims that

“During the 1930s Flowers pioneered the large-scale use of electronic valves to control the making and breaking of telephone connections. He was swimming against the current. Many regarded the idea of large-scale electronic equipment with scepticism. The common wisdom was that valves—which, like light bulbs, contained a hot glowing filament—could never be used satisfactorily in large numbers, for they were unreliable, and in a large installation too many would fail in too short a time. However, this opinion was based on experience with equipment that was switched on and off frequently—radio receivers, radar, and the like. What Flowers discovered was that, so long as valves were switched on and left on, they could operate reliably for very long periods, especially if their ‘heaters’ were run on a reduced current.

…..Flowers did not think much of the Robinson, however. The basic design had been settled before he was called in and he was sceptical as soon as Morrell, head of the teleprinter group, first told him about it. The difficulty of keeping two paper tapes in synchronisation at high speed was a conspicuous weakness. So was the use of a mixture of valves and relays in the counters, because the relays slowed everything down: Heath Robinson was built mainly from relays and contained no more than a couple of dozen valves. Flowers doubted that the Robinson would work properly and in February 1943 he presented Newman with the alternative of a fully electronic machine able to generate the chi-stream (and psi- and motor-streams) internally.

Flowers’ suggestion was received with ‘incredulity’ at TRE and Bletchley Park. It was thought that a machine containing the number of valves that Flowers was proposing (between one and two thousand) ‘would be too unreliable to do useful work’.

Meanwhile Flowers, on his own initiative and working independently at Dollis Hill, began building the fully electronic machine that he could see was necessary. He embarked on Colossus, he said, ‘in the face of scepticism’ from Bletchley Park and ‘without the concurrence of BP’. ‘BP weren’t interested until they saw it [Colossus] working’, he recollected. Fortunately, the Director of the Dollis Hill Research Station, Gordon Radley, had greater faith in Flowers and his ideas, and placed ‘the whole resources of the laboratories’ at Flowers’ disposal.”

“The prototype Colossus was brought to Bletchley Park in lorries and reassembled by Flowers’ engineers. It had approximately 1600 electronic valves and operated at 5000 characters per second. Later models, containing approximately 2400 valves, processed five streams of dot-and-cross simultaneously, in parallel. This boosted the speed to 25,000 characters per second. Colossus generated the chi-stream electronically. Only one tape was required, containing the ciphertext—the synchronisation problem vanished.”

Colossus Mark I was commissioned in January 1944. It proved to be a resounding success.

“Since the early months of 1944, Colossus I had been providing an unparalleled window on German preparations for the Allied invasion. Decrypts also revealed German appreciations of Allied intentions. Tunny messages supplied vital confirmation that the German planners were being taken in by Operation Fortitude, the extensive programme of deceptive measures designed to suggest that the invasion would come further north, in the Pas de Calais. In the weeks following the start of the invasion the Germans tightened Tunny security, instructing operators to change the patterns of the chi- and psi-wheels daily instead of monthly. Hand methods for discovering the new patterns were overwhelmed. With impeccable timing Colossus II’s device for breaking wheel patterns came to the rescue.”

“Once Flowers’ factory in Birmingham was properly up and running, new Colossi began arriving in the Newmanry at roughly six week intervals. Eventually three were dedicated to breaking wheel patterns. Flowers was a regular visitor at B.P. throughout the rest of 1944, overseeing the installation programme for the Mark 2 Colossi. By the end of the year seven Colossi were in operation. They provided the codebreakers with the capacity to find all twelve wheel settings by machine, and this was done in the case of a large proportion of decrypted messages. There were ten Colossi in operation by the time of the German surrender in 1945, and an eleventh was almost ready.”

By the end of the war, 63 million characters of high-grade German communications had been decrypted by 550 people helped by the ten Colossus computers.

The Colossi were all dismantled after the War and all the documentation associated with it were destroyed.

According to wikipedia  “Colossus and the reasons for its construction were highly secret, and remained so for 30 years after the War. Consequently, it was not included in the history of computing hardware for many years, and Flowers and his associates were deprived of the recognition they were due. Colossi 1 to 10 were dismantled after the war and parts returned to the Post Office. Some parts, sanitised as to their original purpose, were taken to Max Newman’s Royal Society Computing Machine Laboratory at Manchester University.

Tommy Flowers was ordered to destroy all documentation and burnt them in a furnace at Dollis Hill. He later said of that order:

“That was a terrible mistake. 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.”

Recognition has come at last, from various quarters including search giant Google. As reported in this article

“Google has been behind the project to film the Bletchley engineers and has posted the movie  on its video-sharing site YouTube.

Peter Barron, head of external relations at the search giants’ UK division says his firm owed the Bletchley engineers a debt of gratitude.

“The engineers who work at Google, both in the UK, in the US and around the world have a great affinity to Bletchley Park and the work of Alan Turing,” he says. “Really because the early ideas of computing, the early ideas of the algorithm were developed there.””

Royal Mail has pitched in with a stamp commemorating the Colossus. The National Museum of Computing in its website has carried an article reporting the event,

“Veteran Colossus operators are delighted with the recognition of Colossus, the world’s first electronic computer, and its designer Tommy Flowers in the latest set of stamps issued by Royal Mail.

Royal Mail’s Inventive Britain stamp issue celebrates eight key inventions of the past century in disciplines and applications ranging from materials to medicine. One of the two first class stamps in the series celebrates Tommy Flower’s creation of Colossus. The series is released on 19 February 2015.”

Tony Sale, a British electronic engineer, computer programmer, computer hardware engineer, and historian of computing led the construction of fully functional Mark 2 Colossus computer between 1993 and 2008.(Yes, it took nearly 15 years to rebuild). The rebuild is exhibited at The National Museum of Computing at Bletchley Park in England.

That is another fascinating story, recounted by Sale himself in this article.

Tommy Flowers and his team of engineers, have at last received the recognition that they deserved. According to this article in the  Telegraph,

“To celebrate Tommy’s contribution to telecommunications, a life-size bronze portrait bust of him now stands at BT’s Adastral Park research laboratories and campus near Ipswich. He is also commemorated in the recently opened Tommy Flowers Institute at Adastral Park, which brings together ICT-sector organisations with academic researchers to solve some of the challenges facing UK businesses, exploring areas such as cyber-security, big data, autonomics and converged networks.”

So, folks the hero of this post and his creation received the recognition that was their due, though in this case one feels that it is a case of recognition delayed, being recognition denied. However, the history of technology is strewn with stories of un-recognized achievements. Let’s look at one of those next week.



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