Press release

Oyu Tolgoi awards major underground contract to Thiess-Khishig Arvin joint venture

Ulaanbaatar, Mongolia,

Oyu Tolgoi today announced the signing of a critical contract for the underground mine development, marking a significant milestone in the continuing ramp up of the construction programme. The contract to execute the Boxcut and Decline for the project has been awarded to a joint venture between Thiess Pty Ltd and Khishig Arvin, a Mongolian civil and mining services company.

The Boxcut 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 Project entails the construction of two parallel tunnels, each approximately 5.5m wide x 6m 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.

Oyu Tolgoi 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.”

About Oyu Tolgoi LLC (

Oyu Tolgoi LLC, Mongolia's largest copper and gold mining company, is a strategic partnership between the Government of Mongolia, Turquoise Hill Resources and Rio Tinto. Located in the South Gobi, Oyu Tolgoi commenced shipment of product to customers in July 2013. Oyu Tolgoi is managed by Rio Tinto, which is investing global expertise and cutting-edge technology to help develop Mongolia’s mining industry and ensure Oyu Tolgoi is one of the world’s most advanced mines. For Oyu Tolgoi, nothing matters more than safety. The business operates under the principle that if a job cannot be done safely, it will not be done at all.

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