The Birth of Colossus – The Story of Tommy Flowers

Tommy Flowers

Recent interest in Alan Turing the codebreaker based at Bletchley Park in the Second World War has led to the re-evaluation of many of the unsung heroes who also worked there.

One of the most interesting of these heroes is Tommy Flowers who not only played a major part in codebreaking but also developed what many  consider to be one of the first electronic computers.

Tommy Flowers was born in Abbott Road, Poplar where he developed his interest in engineering. After leaving school, he completed a four-year apprenticeship in Mechanical Engineering at the Woolwich Arsenal and went to night classes to gain  a degree in Engineering from London University.

However it was when he joined the General Post Office telecommunications branch in 1926 that he developed his interest in Electronics especially into telephone exchanges.

Little did Tommy realise at the time but it was the knowledge gained in the GPO  research station in Dollis Hill that would have a profound effect on Britain’s security and the development of electronic computers.

In 1941 Tommy was asked to work at Bletchley Park with Alan Turing on a project to decode German messages. However it was in 1943 when Turing introduced Tommy to Max Newman that work began on the project that would make their name.

One of the major problems at this time was the code breaking team had access to so much information they needed a way to automate the analysis of the messages.

Tommy was convinced that an electronic system called Colossus would solve the problem, he proposed building a machine with 1800 valves which would automate the process.

To many this seemed a radical solution because of the notorious unreliability of the valves, however Tommy’s experience at the GPO had convinced him that the valves were reliable if they were left on rather constantly switching on and off.

He did not convince the management team but went off and built the machine using old GPO parts and buying some parts with his own money. Tommy and his team built his first machine in 11 months  and it immediately proved its worth by processing 5 times quicker and more accurate than the previous method.

The Colossus machine

Tommy realised that if the machine was successful others would be needed, so began working on an improved second model almost before the first was finished. By the end of the war 10 machines had been made.

Tommy was awarded an MBE as early as 1943, however due to the secret nature of his work and the fact his machines were still being used in the Cold War he was not allowed to develop his ideas commercially and when the war ended he went back to work at the GPO where he was awarded the prestigious Martlesham medal in 1980. He was also involved in the development of ERNIE, the premium bond allocating computer.

It is only in the last few years that the story of Tommy Flowers has been fully told and his contribution to the war effort and development of the modern computer acknowledged.

Unfortunately this was too late for Tommy who died in 1998, however the true legacy of this local hero and the people who worked with him was that their ingenuity and determination at a time when it was badly needed literally saved millions of lives.