In 1937, when the tensions in Europe and Asia were becoming apparent, the Chief of
MI6, Admiral
Hugh Sinclair, ordered GC&CS to begin preparing for a war-footing and to expand its staff numbers. These were to be "men of the professor type", primarily drawn from
Oxford and, in particular,
Cambridge universities. However, as the cryptanalytic work became increasingly mechanized, many more staff were needed. These "debs" performed mostly administrative and clerical work. However, the personnel needs of Bletchley Park continued to grow. The heads of Bletchley Park next looked for women who were linguists, mathematicians, and even
crossword experts. The ability to do crosswords was explored in the interview of Jean Argles a codebreaker employed outside Bletchley Park. In 1942 the
Daily Telegraph hosted a competition where a
cryptic crossword was to be solved within 12 minutes. Winners were approached by the military and some were recruited to work at Bletchley Park, as these individuals were thought to have strong
lateral thinking skills, important for codebreaking. The majority of these women came from middle-class backgrounds and some held degrees in mathematics, physics and engineering; they were given entry into
STEM programs due to the lack of men, who had been sent to war. By the end of 1944 in excess of 2,500 women were employed by GC&CS from the
Women's Royal Naval Service (whose members were called "Wrens"); over 1,500 women were assigned from the
Women's Auxiliary Air Force ("WAAFs") and approximately 400 came from the
Auxiliary Territorial Service. Six out of ten women working in Bletchley Park were serving in the
British Armed Forces. Many of those women were more interested in working on planes and ships, and never expected to work in a place such as Bletchley Park. Women held numerous roles at Bletchley Park, ranging from administrators,
index card compilers and
dispatch riders, to a very few as code-breaking specialists. Initially many of the men in charge were skeptical that women would be able to operate the
Bombe machines and the
Colossus computers; in one section which employed women, including college graduates, the male section head opined that “women wouldn't like to do any intellectual work”.
Gordon Preston persuaded
Max Newman (who thought that the women would not care for the "intellectual effort") to authorise talks to the Wrens to explain their work mathematically, and the talks were very popular. Women in Bletchley Park soon proved themselves to be up to the task, as they performed good work in any position they held at Bletchley Park. Though the initial focus of recruitment, particularly during the latter years of the inter-war period, focused primarily on male academics, there soon emerged an eclectic staff of "
Boffins and
Debs", which caused GC&CS to be whimsically dubbed the "Golf, Cheese and Chess Society". At the outbreak of the war Dilly Knox was the GC&CS's chief cryptanalyst and, as such, took a leading role in the work on the various Enigma networks. His team, which he staffed with women ("Dilly's girls"), included
Margaret Rock and
Mavis Lever, sometimes termed "Dilly's Fillies". During a September 1941 morale-boosting visit,
Winston Churchill reportedly remarked to head of GC&CS
Alastair Denniston: "I told you to leave no stone unturned to get staff, but I had no idea you had taken me so literally."
Women in World War II worked in many places that previously had been largely confined to men, such as industry and the military. Bletchley Park was unusual because the women there worked on demanding intellectual tasks. One of the few directly comparable scenarios during the conflict was that American women were recruited to perform artillery ballistics calculations and to program computers. These women "computers" used a
differential analyzer in the basement of the
Moore School of Electrical Engineering to speed up their calculations, though the machine required a mechanic to be totally accurate and the women often rechecked the calculations by hand. == Selected women ==