The project to expand the Gyeongbu High-Speed Rail line between Pyeongtaek and Osong is a key measure to enhance high-speed rail traffic in South Korea. The goal is to eliminate existing bottlenecks in the rail network and significantly improve the efficiency of the connection between Seoul and other regions of the country. The 46.4-kilometer stretch, which connects Pyeongtaek in the south with Osong, is designed for a maximum speed of 400 km/h.

A critical component of the tunnel construction are the two state-of-the-art tunnel boring machines (TBMs) from Herrenknecht: a Multi-mode TBM and a Gripper TBM. These different machine types ensure efficient and safe tunneling under varying geological conditions.

The Multi-mode TBM began tunneling in December 2024, while the Gripper TBM is scheduled to start in June 2025. With the completion of the expansion, a highly efficient transportation solution will emerge, significantly optimizing South Korea’s high-speed rail network. By eliminating bottlenecks and increasing track capacity, not only will the connection between Seoul and the southern regions be improved, but the efficiency and reliability of the entire high-speed rail system will also be greatly enhanced.