Chinese‑built open‑type hard‑rock TBM rolls off production line for South‑Korean high‑speed‑rail tunnel

On 18 August, the 8‑metre‑class open‑type hard‑rock Tunnel Boring Machine (TBM), named China Railway R469, completed factory acceptance and rolled off the assembly line in Zhengzhou. Manufactured by China Railway Equipment under China Railway Industry, the machine will undertake excavation for the 8.6‑kilometre tunnel on Lot 2 of the Chuncheon‑Sokcho high‑speed railway in South Korea.

The TBM features an excavation diameter of 8.23 metres and a total machine length of 130 metres, engineered to cope with rock strength up to 140 megapascals. To match variable Grade Ⅲ to Grade Ⅴ surrounding‑rock conditions on‑site, engineering teams have integrated a combined support system for steel arch installation, rock‑bolting and shotcreting within confined machine spaces. Emergency generators and refuge chambers are also fitted as safety installations, enabling simultaneous tunnelling and ground‑support operations.

This marks the first entry of Chinese‑manufactured hard‑rock TBM technology into the South‑Korean market. Beyond the main TBM unit, China Railway Equipment will supply ancillary site machinery including vertical belt conveyors, continuous belt conveyors and multi‑purpose rubber‑tyred vehicles, delivering a complete one‑stop construction‑equipment package for tunnel works.

Stretching 93.7 kilometres in total, the Chuncheon‑Sokcho high‑speed railway is designed for operating speeds of 260 kilometres per hour. Once fully completed, journey times between Seoul and Sokcho will fall from nearly three hours to one hour and 39 minutes.

The machine will undergo subsequent pre‑departure checks ahead of shipment to the project site. Its operational performance will be closely monitored as tunnelling progresses, with on‑site teams adjusting working parameters according to actual geological conditions encountered along the tunnel alignment.