In 1943 World War II was at its height. At Bletchley Park the team working on breaking the German secret codes, in particular those based on the use of the Enigma Cipher machine, had achieved great success - partly due to the contributions of Alan Turing. However, German improvements to their coding system and the use of a new cipher machine, built by the Lorenz Company, meant that these hard won successes were in danger of being lost.

Max Newman (born Neumann), Alan Turing’s old lecturer, was in charge of a section at Bletchley Park and Turing worked with him. Turing had contributed significantly to the ideas behind the decoding work. There had already been built some limited electro-mechanical and electronic/electro-mechanical devices (known as Heath-Robinsons) to help the deciphering, though the performance of these had been held back by unreliability and lack of speed.

Max Newman was an excellent mathematician, but he found that, much to his annoyance, he was not in fact very good at deciphering and breaking the codes. He was capable of it, he just didn’t have an affinity for it. He believed however, that much of what he found so tedious and difficult could be automated. He envisioned a purpose-built machine that would be capable of mechanising some of the laborious code-breaking procedures that were currently being done by hand.

However, he had no idea how to build such a machine, or who would be up to the task of doing it. Tommy Flowers, an engineer from the Post Office Research Station (Dollis Hill), had already been working on special-purpose electro-mechanical devices for Bletchley Park. Flowers had a good deal of previous experience in electronic switches from his work at Dollis Hill and Alan Turing was aware of some of his work.

Tommy Flowers believed that what Max Newman wanted was possible. The machine, he reasoned, would have to be able to input the information very fast and use electronic valves to undertake the logical operations that were needed.

This was a very significant act of faith because nothing like the number of 1,500 valves  that would be required had ever been made to operate reliably and continuously before. Despite this, Gordon Radley (in charge of Dollis Hill) gave his complete and financial support to Flowers and the project: a significant indication of the faith he had in his engineers and the importance of the work.

Max Newman