W. Calder became a member of the Mechanical Engineers' Association of the Witwatersrand in 1898, during its first year. Subsequently he was a member of council of its successor, the Transvaal Institute of Mechanical Engineers, from 1906 to 1910. In 1909 he read a paper before its members on "Features of the handling and preparation of gold-bearing rock for cyanide treament as they appeal to a mechanical engineer". The paper was published in the institute's Journal (1909/10, Vol. 8).
Calder was elected president of the South African Institution of Engineers for 1913/4.