Challenging the concept of 'the steel frame' of British colonial administration, analyzed for the first time in the literature is the exact manpower strength of the British colonial administration (District Officers/Commissioners) on the ground in Africa, colony by colony, since ca 1900. Extensive tables consider the recruitment figures for the British Colonial Service during a similar period, based on unpublished material. Presented is a comparative picture of the size, population, & total Colonial Service presence in each of the the British African territories at the height of the empire, ca 1939. Examined is how such a 'thin white line' was able to 'keep the King's Peace' so successfully, & four answers are suggested: coercion, collaborators, competence, & confidence. The essence of the steel frame lies not in its size but in its strength: tensileness & confidence in performance rather than brute strength are traditionally the hallmark of top-grade steel the world over. 14 Tables. AA.