Hambuk Line
The Cheongjin−Hoeryeong–Sambong (formerly Sangsambong) section of the Hamgyeong Line inherited from Sentetsu was merged with the former Sambong−Namyang North Chosen West Line, the Namyang−Unggi section of the North Chosen East Line, and the Unggi−Najin Ungna Line inherited from Mantetsu to create the new Hambuk Line running from Cheongjin to Najin via Namyang. The Namyang−Tumen cross-border section of the North Chosen East Line was split off to create the Namyang Gukgyeong Line.