The Associated Society of Locomotive Engineers and Firemen was established in 1880, and the first Aberdeen branch formed in October 1907. By 1938 there were 2 branches in the city, with a total membership of c.250. The Keith branch was formed on 27 October 1918, and was wound up on 2 November 1968, with remaining members transferring to Aberdeen at that time.
Norman McKillop, The Lighted Flame; a history of the Associated Society of Locomotive Engineers and Firemen (London: Nelson, 1950), and John R. Rayne, Engines and Men: the history of the Associated Society of Locomotive Engineers and Firemen: a survey of organisation of railway locomotive men (Leeds: Goodall and Suddick, 1921) contain more details about the national organisation. Further information about the development of the trade union movement and the history of individual trade unions in Aberdeen can be found in William Diack, History of the Trades Council and the Trade Union Movement in Aberdeen (Aberdeen: Aberdeen Trades Council, 1939), and in Kenneth D. Buckley, Trade Unionism in Aberdeen 1870 - 1900 (Edinburgh and London: Oliver and Boyd, 1955). Arthur Marsh and Victoria Ryan, Historical Directory of Trade Unions, 4 vols (Aldershot: Gower, 1980 - 1984) also contains useful information about the development of individual unions, at both the national and local level. Summarised details from these sources has been used in compiling this collection level description.