Yulhyeon Tunnel

The Yulhyeon Tunnel is a railway tunnel in South Korea, which opened in December 2016, is currently the world's fourth longest railway tunnel at 50.3 kilometers. The tunnel, which consists of a double-track tube, is part of the 61.1-kilometer Suseo–Pyeongtaek high-speed railway that connects Suseo station in the southeastern part of Seoul with the Gyeongbu high-speed railway. The threading into the older high-speed line is in the south of the city of Pyeongtaek. The tunnel itself takes up about 82% of the total new line. The Yulhyeon Tunnel was built using the New Austrian tunnelling method (NATM) and is designed for a maximum speed of 300 km/h. The average cruising speed is about 240 km/h due to the intermediate stop at Dongtan Station in the southern part of the tunnel.[1]