trade union movement in New South Wales, but by the mid-1920s it had dwindled to an insignificant sect, and Garden and other communists were expelled from the Labor Party in 1924. However, the Communist Party began to win positions in particular trade unions, such as the Miners Federation and the Waterside Workers' Federation of Australia. Strikes in this period were commonplace, and remained threatening to the Commonwealth government, which took measures to control union activity. In 1926 the federal Crimes Act was amended for the Act to apply to unions and in 1928 the Transport Workers Act 1928 (more commonly referred as the Dog Collar Act) was enacted, directed against the Waterside Workers' Federation. Of particular note is the 1923 Victorian Police strike. Trade union membership was 703,000 in 1921 and reached its peak in 1927, according to Green and Cromwell, when trade union membership "comprised less than 15 per cent of the whole population, only 47 per cent of the workforce." In 1931 union membership was 769,000. The Great Depression After the Transport Workers Act 1928, more widely known as The Dog Collar Act, was passed, the Australian union movement sought to protect itself by forming a permanent national trade union organisation, the Australian Council of Trade Unions. By this point the idea of trade unionism had won out over industrial unionism. This was in part encouraged by the industrial courts which freely gave registration to small, shop and trade-specific unions. While the Communist Party of Australia would always argue for industrial unions, the idea of industrial unions smouldered until the 1960s, and only received support from the ACTU and the ALP in the 1980s. The Dog Collar Act was used to break up strong unions, in forestry and on the docks. These unions were perceived to be revolutionary, or at least militant. At the same time the fragmented trade unions sought to maintain member conditions in an environment of massive unemployment. For instance, rates of male unemployment in the industrial city of Newcastle never dropped below 20% throughout the 1920s. When the Great Depression hit, formal unemployment rates rose above 30%. The 1929 Australian timber workers' strike was the first large strike during the depression when Justice Lukin handed down a new timber industry award that increased the working week from 44 to 48 hours and reduced wages. During the strike Lukin ordered a secret ballot to be