Construction started on 12 January 1912 at Dombås. The work was divided into four geographic divisions, with offices located at Åndalsnes, Ormheim, Sørsletten and Holaker. The working week consisted of six days, with a ten-hour working day during summer, eight hours during winter and nine hours in spring and autumn. From 1921, a new law reduced the work week to 48 hours. The entire construction took 14,462,247 man-hours. The number of people employed varied between 615 and 550. Most of the workforce consisted of people from other parts of the country, and some foreigners, mostly from Sweden. The navvies were often unmarried and spent large parts of their income on alcohol.