Stuart Macrae's career in engineering began when he briefly worked for the Westinghouse Brake and Saxby Signal Company as an apprentice. He then became a trainee draughtsman at an aircraft company, soon moving on to design work, including a project for the Air Ministry at the end of the First World War designing bomb release gear. After the war, Macrae returned to aircraft design work, then became a technical journalist, eventually becoming editor of a number of technical journals. While Macrae was working for Odhams Press Limited in 1939 as editor of the magazine Armchair Science, he was recruited by Major Millis Jefferis to be his second-in-command in the Military Intelligence Research (MIR) branch of the War Office.
MIR was responsible for inventing many sabotage devices for organisations including the Special Operations Executive (SOE). Later in the war it turned to the development of high explosives, including weapons which Macrae worked on such as the anti-tank grenade, or Sticky Bomb, the magnetic Limpet Bomb, the "M" anti-personnel mine, the Water Bomb, and numerous other bombs and grenades.
When SOE was formed in 1940 from MIR and other organisations, Jefferis's technical group became a department of the Ministry of Defence instead, known as M.D.1, which was based at Whitchurch, Buckinghamshire. Macrae was responsible for the management of M.D.1, but in November 1945 the department was merged with the Armament Development Establishment, and was closed down in early 1947.
The papers include: Millis Jefferis's copies of M.D.1 correspondence; administration files on staffing and weapons development; research files on the development of individual weapons; Macrae's patent claims, which include original material on the development of the weapons concerned; Macrae's diaries from his time at M.D.1; some material from Macrae's memoirs, "Winston Churchill's Toyshop".
The papers were deposited at Churchill Archives Centre by Colonel Macrae in December 1971.
The collection is open for consultation by researchers using Churchill Archives Centre, Churchill College, Cambridge. Churchill Archives Centre is open from Monday to Friday, 9am-5pm. A prior appointment and two forms of identification are required.
Researchers wishing to publish excerpts from the papers must obtain prior permission from the copyright holder(s) and should seek advice from Archives Centre staff.
Please cite as Churchill Archives Centre, The Papers of Colonel R S Macrae, MCRA
Macrae's memoirs of his time in M.D.1 were published in "Winston Churchill's Toyshop" (Kineton: the Roundwood Press, 1971).
A copy of this finding aid is available for consultation at Churchill Archives Centre, Cambridge, the National Register of Archives, London and on the Janus website, http://janus.lib.cam.ac.uk/.
This finding aid was prepared by Katharine Thomson of Churchill Archives Centre in April 2008. Biographical information was taken from Macrae's "Winston Churchill's Toyshop".