How did the 1911 Mines and Works Act create a job colour bar in South African mining?

The Mines and Works Act of 1911 formally established a "job colour bar" in South African mining by legally reserving skilled labor positions for white workers.12

This legislation was designed to protect white miners from the economic competition of cheaper, semiskilled Black labor, which mine owners sought to utilize to reduce operational costs. By enshrining the custom of white-only skilled labor into law, the act ensured that white workers maintained access to high-paying roles—often earning wages five to ten times higher than those of their Black counterparts—while systematically excluding Black workers from these positions.13

This statutory barrier was part of a broader framework of segregationist policies intended to regulate class and race relations during South Africa's rapid industrialization. The colour bar was further reinforced by a 1926 amendment to the act and subsequent industrial legislation that excluded Black workers from wage-bargaining machinery, effectively cementing their subordinate status within the mining industry's economic structure.21