Thomas (Tommy) Harold Flowers, MBE (22 December 1905 – 28 October 1998) was a British engineer. During World War II, Flowers designed Colossus, an early electronic computer, to help solve encrypted German messages. Commanders Badge of the Order of the British Empire (Military division) The Most Excellent Order of the British Empire is a British order of chivalry established on 4 June 1917 by King George V. The Order includes five classes in civil and military divisions; in decreasing order of seniority... December 22 is the 356th day of the year (357th in leap years) in the Gregorian Calendar. ... 1905 (MCMV) was a common year starting on Sunday (see link for calendar). ... October 28 is the 301st day of the year (302nd in leap years) in the Gregorian Calendar, with 64 days remaining. ... 1998 (MCMXCVIII) was a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ... Combatants Major Allied powers: United Kingdom France Soviet Union United States Republic of China and others Major Axis powers: Germany Italy Japan and others Commanders Winston Churchill Charles de Gaulle Joseph Stalin Franklin Roosevelt Chiang Kai-Shek Adolf Hitler Benito Mussolini Hideki Tojo Casualties Military dead: 17,000,000 Civilian... A Colossus Mark II computer. ... A BlueGene supercomputer cabinet. ...

Flowers was born in London's East End on 22 December 1905, the son of a bricklayer^[1]. After an apprenticeship in mechanical engineering, he earned a degree in electrical engineering at the University of London. In 1926, he joined the telecommunications branch of the General Post Office (GPO), moving to work at the research station at Dollis Hill on the northwest side of London in 1930. From 1935 onward, he explored the use of electronics for telephone exchanges. By 1939, he was convinced that an all-electronic system was possible. This background in switching electronics would prove crucial for his computer design in World War II. The term East End is most commonly used to refer to the East End of London. ... December 22 is the 356th day of the year (357th in leap years) in the Gregorian Calendar. ... Masonry is the building of structures from individual units laid in and bound together by mortar. ... Mechanical engineers design and build engines and power plants. ... Electrical Engineers design power systems… … and complex electronic circuits. ... The University of London is a university based primarily in London. ... Year 1926 (MCMXXVI) was a common year starting on Friday (link will display the full calendar). ... The British General Post Office (GPO) was officially established in 1660 by Charles II and it eventually grew to combine the functions of both the state postal system and telecommunications carrier. ... The Post Office Research Station at Dollis Hill, London, was first established in 1921 and opened by the Prime Minister Ramsay MacDonald in 1933. ... Dollis Hill is an area of north-west London. ... Year 1930 (MCMXXX) was a common year starting on Wednesday (link is to a full 1930 calendar). ... 1935 (MCMXXXV) was a common year starting on Tuesday (link will take you to calendar). ... 1939 (MCMXXXIX) was a common year starting on Sunday (link will take you to calendar). ...

World War II

Flowers's first contact with the wartime codebreaking effort came when he was asked for help by Alan Turing, who was then working at the government's Bletchley Park codebreaking establishment 50 miles north of London. 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 introduced him to Max Newman who was leading the effort to break a teletype-based cipher, called "Geheimschreiber" (secret writer) by the Germans and "Fish" by the English decoding team. This was a much more complex coding system than Enigma; the decoding procedure involved trying so many possibilities that it was impractical to do by hand. In February 1943, Flowers proposed an electronic system using 1500 valves (vacuum tubes). Because the most complicated previous electronic device had used about 150 valves, some were skeptical that such a device 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 that included having the circuitry on all the time. The Bletchley Park management were not convinced, however, and merely encouraged Flowers to proceed on his own. Alan Turing is often considered the father of modern computer science. ... During World War II, codebreakers at Bletchley Park solved messages from a large number of Axis code and cipher systems, including the German Enigma machine. ... The Bombe replicated the action of several Enigma machines wired together. ... The plugboard, keyboard, lamps and finger-wheels of the rotors emerging from the inner lid of a three-rotor German military Enigma machine (version with labels) For other uses, see Enigma. ... Maxwell Herman Alexander Newman (February 7, 1897 – February 22, 1984) was a British mathematician. ... Look up enigma in Wiktionary, the free dictionary. ... In electronics, a vacuum tube or (outside North America) thermionic valve or just valve, is a device generally used to amplify, switch or otherwise modify, a signal by controlling the movement of electrons in an evacuated space. ...

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. It operated 5 times faster and was more flexible than the previous system, named Heath Robinson, which used electro-mechanical switches. Anticipating the need for additional computers, a redesign utilizing 2400 valves was begun before the first computer was finished. The Mark 2 operated 5 times faster than the first Colossus. Flowers estimated that they could be manufactured at a rate of about one per month. Years later, Flowers described the design and construction of these computers^[2]. Heath Robinson was a machine used by British codebreakers at Bletchley Park during World War II to solve messages in a German teleprinter cipher, the Lorenz SZ40/42. ...

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 British secret service headquarters, where they may have played a significant part in the codebreaking operations of the Cold War".^[3] They were finally decommissioned in 1959 and 1960. Combatants Major Allied powers: United Kingdom France Soviet Union United States Republic of China and others Major Axis powers: Germany Italy Japan and others Commanders Winston Churchill Charles de Gaulle Joseph Stalin Franklin Roosevelt Chiang Kai-Shek Adolf Hitler Benito Mussolini Hideki Tojo Casualties Military dead: 17,000,000 Civilian... The Cold War was the period of conflict, tension and competition between the United States and the Soviet Union and their allies from the mid 1940s until the early 1990s. ... Year 1959 (MCMLIX) was a common year starting on Thursday of the Gregorian calendar. ... 1960 (MCMLX) was a leap year starting on Friday (the link is to a full 1960 calendar). ...

Post-war work

After the war, Flowers was awarded limited recognition through an Order of the British Empire at the lowest level of MBE (member) and £1,000. His work in computing was not properly acknowledged until the 1970s, because the project was restricted by the Official Secrets Act. His family had known only that he had done some 'secret and important' work^[4]. He remained at the Post Office Research Station where he was Head of the Switching Division. He and his group pioneered work on all-electronic telephone exchanges, completing a basic design by about 1950. In 1964 he became Head of the Advanced Development Group at Standard Telephones and Cables Ltd., retiring in 1969^[5]. Commanders Badge of the Order of the British Empire (Military division) The Most Excellent Order of the British Empire is a British order of chivalry established on 4 June 1917 by King George V. The Order includes five classes in civil and military divisions; in decreasing order of seniority... ISO 4217 Code GBP User(s) United Kingdom Inflation 2. ... Official Secrets Act warning sign, Foulness. ... The Post Office Research Station at Dollis Hill, London, was first established in 1921 and opened by the Prime Minister Ramsay MacDonald in 1933. ... A Verizon Central Office in Lakeland, Florida at night. ... 1950 (MCML) was a common year starting on Sunday (link will take you to calendar). ... 1964 (MCMLXIV) was a leap year starting on Wednesday (the link is to a full 1964 calendar). ... Standard Telephones and Cables Ltd (later STC plc) was a British telephone, telegraph, radio, telecommunications and related equipment R&D manufacturer. ... Year 1969 (MCMLXIX) was a common year starting on Wednesday (the link is to a full 1969 calendar). ...

References

1. ^ Jon Agar, "Flowers, Thomas Harold (1905-1998), engineer" in the Oxford Dictionary of National Biography, 2004
2. ^ http://www.ivorcatt.com/47c.htm
3. ^ Transcript of 1999 Nova television program "Decoding Nazi Secrets"
4. ^ BBC, 2003, obituary for Tommy Flowers: Technical Innovator
5. ^ http://www.cs.ncl.ac.uk/research/pubs/books/papers/133.pdf

• B.J. Copeland, ed., "Colossus: The Secrets of Bletchley Park's Codebreaking Computers," Oxford University Press, 2006.

External links

• The Design of Colossus – Thomas H. Flowers
• Quotes about Flowers
• A Real English Hero has Died: a Father of the Modern Computer — The Daily Telegraph