Oyu Tolgoi opened an Avarga Chamber on April 14 to transition its underground mine operation from development to production phase. The Avarga Chamber, measuring 25 meters in height and 20 meters in width, was built by 15 workers per shift for 210 days at the underground mine in Umnugovi Province. In other words, it is as big as five Olympic swimming pools. The team reported outstanding safety record with no injuries during the construction. The chamber will house Primary Crusher-1, which weighs 300 tons. Oyu Tolgoi representatives noted that it will be the largest piece of equipment underground. The chamber required ground support with additional cables with a diameter larger than 22 mm installed 14 meters into the ground to anchor the ground support in order to create a stable arch. Normally, eight-meter-long cables are used in mines but Oyu Tolgoi used 14-meter-long cables. When the crusher becomes operational, large chunks of rocks and excavated products will be crushed at the Primary Crusher-1 to smaller sizes so that it can be taken out of the mine. The crusher is capable of crushing 4,000 tons of coarse materials per hour. The crusher is nine meters tall, almost the same size as the Statue of Sukhbaatar in Sukhbaatar Square. Hence, a large excavation work is required to fit the crusher in the chamber. The excavation work has been underway since August 30, 2017 and is expected to finish in December 2018. Oyu Tolgoi plans to start assembling the crusher in January next year in order to commission it by June 2020.