North Chosen Colonial Railway

In order to exploit the rich iron deposits of the Musan region, the Chōsen Railway established the North Chōsen Colonial Railway as a subsidiary company^[1] and began construction of a new line, calling it the Hambuk Line (not to be confused with the current Hambuk Line, which at that time was part of the Chosen Government Railway's (Sentetsu) Hamgyeong Line). The line was opened in two parts - the Gomusan-Hambuk Sincham section opening on 20 August 1927, and the Sinch'am-Musan segment opening on 15 November 1929. On 1 February 1937, Musan Cheolsan Station was opened.^[2]

Originally built as a narrow-gauge line, the conversion to standard gauge was completed on 1 May 1940,^[3] and the extension to Musan Gangan station was completed then as well. On 1 April 1944, the line was absorbed into Sentetsu;^[4] at the same time, the line was given its current name, Musan Line, and the extension to Musan Gangan station was closed.^[4]

After the partition of Korea the line was within the territory of the DPRK, and was nationalised by the Provisional People's Committee for North Korea along with all other railways in the Soviet zone of occupation on 10 August 1946;^[5] the line retained the name given it by Sentetsu, Musan Line.^[5]

In the last timetable issued prior to the start of the Pacific War in November 1942, the North Chōsen Colonial Railway was operating four daily round trip passenger trains between Gomusan and Musan, timed to connect with local and express services on Sentetsu's Hamgyeong Line.^[6]