Long Days

The steel making process required continuous operation, 24 hours a day, 7 days a week.
The simplest method of achieving this was to operate two shifts of 12 hours each.
These long days were exhausting and healthhazardous and they disturbed family life
at home, with men unable to spend time with their wives and children. 12-hour days
were common in most early industries.
Photograph: Steel Mill Workers, Sparrows Point, MD, 1940 — Library of Congress