After the partition of Korea following the end of World War 2 and the subsequent establishment of the DPRK, the line was nationalised and its name was changed to the current name. In 1961-62 the line, which by that time was outdated in technical terms, was upgraded with modern equipment; at the same time, a extension from Paekkŭmsan to Kŭmgol was built. The entire line was then electrified in 1977, improving the total capacity, safety and train speeds on the line. The final extension from Kŭmgol to Muhak was built after 1988.