Tunnel contractor, Kusan Construction, is drawing close to breakthrough on the 2.5km long Shu Chon rail tunnel, 10km south of Chuncheon in Korea. Using a Tamrock Jumbo, the local contractor is currently excavating the tunnel by drill and blast to dimensions of 9.6m wide at the base and a maximum height of 7.8m. A V-cut blast pattern has been adopted with 130 – 140 holes to a depth of 4m per blast. Kusan Construction reports a blast advance evey three hours. This is being carried out twice a day, three times a week with each blast producing 700m3 of granite. The Shu Chon tunnel is one of six tunnels totaling 12.5km on the 80km long Seoul to Chuncheon double-track high-speed rail line. The line is being built to allow commuters to cover the 80km in less than 45 minutes and is scheduled to open in 2010.
