 The centerpiece of the last section was the long Jeongam Tunnel, which was the longest in South Korea before the opening of longer tunnels on the Jeolla Line and the Gyeongbu High Speed Railway, and Chujeon Station at the eastern end of the tunnel is the one on the highest altitude in South Korea at above the sea.The line was among the first foreseen for electrification with the 25 kV/60 Hz system in South Korea.Works started in 1972, already before the Taebaek Line was completed and officially renamed.