After the General Strike, cost-cutting measures were introduced in all mines, including in safety provision. Five local collieries - Westminster, Wrexham &amp; Acton, Vauxhall and Gatewen - shut in quick succession during the 1920s and 1930s. Mechanisation, believed by the workers and unions to improve working conditions, created more dust and explosions, in an economic climate where the government were reluctant to enforce regulation.