 As one of the two main unions of coal trimmers in the UK, in 1913 the union affiliated to the National Transport Workers' Federation, and its president, Joshua Thomas Clatworthy, was elected to its executive committee.The links made there led it to form the National Joint Trimmers Committee in 1920, with the North of England Trimmers' and Teemers' Association, and other transport unions which represented trimmers in Scotland and southern England.Clatworthy became the leading union member on the joint committee.