Gordon Welchman

Gordon Welchman joined Bletchley Park in September 1939. He had a gift for planning and organisation and was appointed Head of Hut 6: he conceived the "diagonal board": a dramatic improvement to Turing's Bombe. Appointed Head of Machine Coordination and Development Section in September 1943, he was responsible for the security of machine cyphers, the development of cypher machines and machines for communications and interception.

Welchman wrote many constructive policy papers for Travis on Bombes and machine processing. He reached Directorate level in March 1944 when appointed Assistant Director of Machines and Mechanical Devices.

His brilliant career at Bletchley Park was overshadowed by controversy when he published details of his wartime work against the wishes of UK and US authorities in the early 1980s.