Last Thursday, Oyu Tolgoi (OT) signed a contract with Australian mine service provider Thiess Pty. Ltd. and Khishig Arvin, a Mongolian civil and mining service company. The two companies will work together to execute the box cut and decline for the underground mine. The box cut entails a major excavation of approximately 240,000 cubic meters of bulk earthworks, which will create an access point and enable development of the decline. The decline for the underground mine entails the construction of two parallel tunnels, each approximately 5.5 meters wide and six meters high, running approximately 6.5 km from the surface to underground. One tunnel will be used primarily for the movement of people and vehicles, while the second tunnel will accommodate a conveyor system to transport mined material – ore and waste rock – to the surface. The underground development will also include 35,000 cubic meters of mass excavation. OT’s Chief Development Officer Marco Pires said, “This is a significant contract for the underground project, and all the more so in bringing together international expertise and local partnership that will bring new skills, capacity and expertise to Mongolia, helping develop not only Oyu Tolgoi, but more broadly support the development of the Mongolia’s mining sector.”