In 1905, dockworkers in Rotterdam harbour organized a great strike against the introduction of machines for the transhipment of grain. The initial success of this strike was a profound shock to the leaders of political parties and national labour organizations, who, in spite of many differences of opinion, shared a positive attitude towards mechanization and regarded strikes against machinery as reactionary. The conflict in Rotterdam provoked a national debate about the implications of mechanization, which clearly exposed the strains and contradictions in this “dominant ideology of technology”. The article shows how several local labour leaders questioned the legitimacy of this ideology and why they failed in the end to persuade their superiors.