Before the war John Cockcroft was running the Cavendish Laboratory at Cambridge University. He worked with Walton on the acceleration of protons by high voltages to split the atom in the laboratory.

About a year before the war, Watson Watt told him about radar, and persuaded him to release WB Lewis, his most senior researcher, to go to Bawdsey to manage the radar research programme for Jimmy Rowe.  Before the war (in July/Aug 1939) Cockcroft arranged for about 80 researchers from the Cavendish Laboratories (and other universities) to go to Chain Home stations on the east and south coasts to learn about radar (then called Radio Direction Finding).  This was so that they would be able to act as nurse maids for the stations in the event war was declared.

After the sinking of a battleship in Scapa Flow in Scotland, Cockroft was asked to set up some radars which could warn of approaching submarines.  He went to the Bawdsey Research Station with Jack Ratcliffe (and others) to put together a Coastal Defence radar which they installed on a suitable site.  When it was working, it detected low flying aircraft at a range of 70 miles.  The RAF asked for equipment to be built based on this, to supplement the Chain Home stations which were not good at detecting low flying aircraft.  The new equipment was called Chain Home Low (CHL).

In the autumn of 1940 he was a member of the Tizard Mission to the United States sharing radar secrets with the Americans.  After this he was appointed Superintendent of the Air Defence Research and Development Establishment (ADRDE) in Christchurch which later moved to Pale Manor Farm in Malvern. In 1944 he went to Canada to take charge of the Canadian Atomic Energy project until 1946 when he returned to England as Director of the Atomic Energy Research Establishment (AERE), Harwell.

After the war he held many senior advisory positions to the government in the UK.

27 May 1897 - 18 Sept 1967.

Bill Penley Jan 2011