The plans were approved by Parliament in 1916. However, the decision concerning technical specifications was not taken by Parliament until 1923, when it decided that the line was to be electric. The line was then estimated to cost NOK 14.5 million—the increase caused by inflation during the First World War—of which NOK 1.2 million was to be paid by the local governments. The line was to have tracks which weighed 25 kilograms per meter (50 lb/yd). The curve radius was set to minimum , although exceptionally was permitted. The steepest permitted gradient was 5.5 percent (1:18).