MontImageMedia - In Memoriam
"A Tribute to the forgotten Bletchley Park codebreakers" Mark 2 Colossus computer. Inset W. T. Tutte & Tommy Flowers.
W. T. Tutte :
Soon after the outbreak of World War II, Tutte's tutor, Patrick Duff, suggested him for war work at the Government Code and Cypher School at Bletchley Park (BP). He was interviewed and sent on a training course in London before going to Bletchley Park, where he joined the Research Section. At first he worked on the Hagelin cipher that was being used by the Italian Navy. This was a rotor cipher machine that was available commercially, so the mechanics of enciphering was known, and decrypting messages only required working out how the machine was set up.
In the summer of 1941, Tutte was transferred to work on a teleprinter cipher system that had been dubbed "Tunny". Telegraphy used the 5-bit International Telegraphy Alphabet No. 2 (ITA2). Other than that messages were preceded by a 12-letter indicator, which implied a 12-wheel rotor cipher machine, nothing was known about the mechanism of enciphering. The first step, therefore, had to be to diagnose the machine by establishing the logical structure and hence the functioning of the machine. Tutte played a pivotal role in achieving this, and it was not until shortly before the allied victory in Europe in 1945, that Bletchley Park acquired a Tunny Lorenz cipher machine. Tutte's breakthroughs led eventually to bulk decrypting of Tunny-enciphered messages between German High Command (OKW) in Berlin and their army commands throughout occupied Europe, that played a crucial part in shortening the war.
Tommy Flowers:
Flowers's first contact with the wartime codebreaking effort came in February 1941 when his director, W Gordon Radley was asked for help by Alan Turing, who was then working at the government's Bletchley Park codebreaking establishment 50 miles north west of London in Buckinghamshire. Turing wanted Flowers to build a decoder for the relay-based Bombe machine, which Turing had developed to help decrypt the Germans' Enigma codes. Although the decoder project was abandoned, Turing was impressed with Flowers's work, and in February 1943 introduced him to Max Newman who was leading the effort to automate part of the cryptanalysis of the Lorenz cipher. This was a high-level German cipher generated by a teletypewriter in-line cipher machine, the SZ40/42, one of their "Geheimschreiber" (secret writer) systems, that was called "Tunny" by the British. It was a much more complex system than Enigma; the decoding procedure involved trying so many possibilities that it was impractical to do by hand. Flowers and Frank Morrell (also at Dollis Hill) designed the Heath Robinson, the first machine designed to decrypt the Lorenz or “Fish” machine cyphers.
Flowers proposed an electronic system, which he called Colossus, using perhaps 1,800 thermionic valves (vacuum tubes), and having only one paper tape instead of two (which required synchronisation) by generating the wheel patterns electronically. Because the most complicated previous electronic device had used about 150 valves, some were sceptical that the system would be reliable. Flowers countered that the British telephone system used thousands of valves and was reliable because the electronics were operated in a stable environment with the circuitry on all the time. The Bletchley Park management were not convinced, however, and merely encouraged Flowers to proceed on his own. He did so, providing much of the funds for the project himself. Flowers had first met (and got on with) Turing in 1939, but was treated with disdain by Gordon Welchman, because of his advocacy of valves rather than relays. Welchman preferred the views of Wynn-Williams and Keene of BTM, and wanted Radley and “Mr Flowers of Dollis Hill” removed from work on Colossus for “squandering good valves”.
On 2 June 1943, Flowers was made a Member of the Order of the British Empire.
In 1994, a team led by Tony Sale (right) began a reconstruction of a Colossus at Bletchley Park. Here, in 2006, Sale supervises the breaking of an enciphered message with the completed machine.
Flowers gained full backing for his project from the director of Dollis Hill, W. G. Radley. With the highest priority for acquisition of parts, Flowers's extremely dedicated team at Dollis Hill built the first machine in 11 months. It was immediately dubbed 'Colossus' by the Bletchley Park staff for its immense proportions. The Mark 1 Colossus operated five times faster and was more flexible than the previous system, named Heath Robinson, which used electro-mechanical switches. The first Mark 1, with 1500 valves, ran at Dollis Hill in November 1943, and then at Bletchley Park in January 1944.
A Mark 2 redesign utilizing 2,400 valves had begun before the first computer was finished, in anticipation of a need for additional computers. The first Mark 2 Colossus went into service at Bletchley Park on 1 June 1944, and immediately produced vital information for the imminent D-Day landings planned for Monday 5 June (postponed 24 hours by bad weather). Flowers later described a crucial meeting between Dwight D. Eisenhower and his staff on 5 June, during which a courier entered and handed Eisenhower a note summarizing a Colossus decrypt. This confirmed that Hitler wanted no additional troops moved to Normandy, as he was still convinced that the preparations for the Normandy Landings were a diversionary feint. Handing back the decrypt, Eisenhower announced to his staff, "We go tomorrow."[6] Earlier, a report from Field Marshall Rommel on the western defences was decoded by Colossus and revealed that one of the sites chosen as the drop site for an US parachute division was the base for a German tank division. The site was changed.[7]
Years later, Flowers described the design and construction of these computers.[8] Ten Colossi were completed and used during World War II in British decoding efforts, and an eleventh was ready for commissioning at the end of the war. All but two were dismantled at the end of the war. "The remaining two were moved to a British Intelligence department, GCHQ in Cheltenham, Gloucestershire, where they may have played a significant part in the codebreaking operations of the Cold War".
"A Tribute to the forgotten Bletchley Park codebreakers" Mark 2 Colossus computer. Inset W. T. Tutte & Tommy Flowers.
W. T. Tutte :
Soon after the outbreak of World War II, Tutte's tutor, Patrick Duff, suggested him for war work at the Government Code and Cypher School at Bletchley Park (BP). He was interviewed and sent on a training course in London before going to Bletchley Park, where he joined the Research Section. At first he worked on the Hagelin cipher that was being used by the Italian Navy. This was a rotor cipher machine that was available commercially, so the mechanics of enciphering was known, and decrypting messages only required working out how the machine was set up.
In the summer of 1941, Tutte was transferred to work on a teleprinter cipher system that had been dubbed "Tunny". Telegraphy used the 5-bit International Telegraphy Alphabet No. 2 (ITA2). Other than that messages were preceded by a 12-letter indicator, which implied a 12-wheel rotor cipher machine, nothing was known about the mechanism of enciphering. The first step, therefore, had to be to diagnose the machine by establishing the logical structure and hence the functioning of the machine. Tutte played a pivotal role in achieving this, and it was not until shortly before the allied victory in Europe in 1945, that Bletchley Park acquired a Tunny Lorenz cipher machine. Tutte's breakthroughs led eventually to bulk decrypting of Tunny-enciphered messages between German High Command (OKW) in Berlin and their army commands throughout occupied Europe, that played a crucial part in shortening the war.
Tommy Flowers:
Flowers's first contact with the wartime codebreaking effort came in February 1941 when his director, W Gordon Radley was asked for help by Alan Turing, who was then working at the government's Bletchley Park codebreaking establishment 50 miles north west of London in Buckinghamshire. Turing wanted Flowers to build a decoder for the relay-based Bombe machine, which Turing had developed to help decrypt the Germans' Enigma codes. Although the decoder project was abandoned, Turing was impressed with Flowers's work, and in February 1943 introduced him to Max Newman who was leading the effort to automate part of the cryptanalysis of the Lorenz cipher. This was a high-level German cipher generated by a teletypewriter in-line cipher machine, the SZ40/42, one of their "Geheimschreiber" (secret writer) systems, that was called "Tunny" by the British. It was a much more complex system than Enigma; the decoding procedure involved trying so many possibilities that it was impractical to do by hand. Flowers and Frank Morrell (also at Dollis Hill) designed the Heath Robinson, the first machine designed to decrypt the Lorenz or “Fish” machine cyphers.
Flowers proposed an electronic system, which he called Colossus, using perhaps 1,800 thermionic valves (vacuum tubes), and having only one paper tape instead of two (which required synchronisation) by generating the wheel patterns electronically. Because the most complicated previous electronic device had used about 150 valves, some were sceptical that the system would be reliable. Flowers countered that the British telephone system used thousands of valves and was reliable because the electronics were operated in a stable environment with the circuitry on all the time. The Bletchley Park management were not convinced, however, and merely encouraged Flowers to proceed on his own. He did so, providing much of the funds for the project himself. Flowers had first met (and got on with) Turing in 1939, but was treated with disdain by Gordon Welchman, because of his advocacy of valves rather than relays. Welchman preferred the views of Wynn-Williams and Keene of BTM, and wanted Radley and “Mr Flowers of Dollis Hill” removed from work on Colossus for “squandering good valves”.
On 2 June 1943, Flowers was made a Member of the Order of the British Empire.
In 1994, a team led by Tony Sale (right) began a reconstruction of a Colossus at Bletchley Park. Here, in 2006, Sale supervises the breaking of an enciphered message with the completed machine.
Flowers gained full backing for his project from the director of Dollis Hill, W. G. Radley. With the highest priority for acquisition of parts, Flowers's extremely dedicated team at Dollis Hill built the first machine in 11 months. It was immediately dubbed 'Colossus' by the Bletchley Park staff for its immense proportions. The Mark 1 Colossus operated five times faster and was more flexible than the previous system, named Heath Robinson, which used electro-mechanical switches. The first Mark 1, with 1500 valves, ran at Dollis Hill in November 1943, and then at Bletchley Park in January 1944.
A Mark 2 redesign utilizing 2,400 valves had begun before the first computer was finished, in anticipation of a need for additional computers. The first Mark 2 Colossus went into service at Bletchley Park on 1 June 1944, and immediately produced vital information for the imminent D-Day landings planned for Monday 5 June (postponed 24 hours by bad weather). Flowers later described a crucial meeting between Dwight D. Eisenhower and his staff on 5 June, during which a courier entered and handed Eisenhower a note summarizing a Colossus decrypt. This confirmed that Hitler wanted no additional troops moved to Normandy, as he was still convinced that the preparations for the Normandy Landings were a diversionary feint. Handing back the decrypt, Eisenhower announced to his staff, "We go tomorrow."[6] Earlier, a report from Field Marshall Rommel on the western defences was decoded by Colossus and revealed that one of the sites chosen as the drop site for an US parachute division was the base for a German tank division. The site was changed.[7]
Years later, Flowers described the design and construction of these computers.[8] Ten Colossi were completed and used during World War II in British decoding efforts, and an eleventh was ready for commissioning at the end of the war. All but two were dismantled at the end of the war. "The remaining two were moved to a British Intelligence department, GCHQ in Cheltenham, Gloucestershire, where they may have played a significant part in the codebreaking operations of the Cold War".