The open pit accesses the Southern Oyu deposit, one of three deposits discovered at Oyu Tolgoi. Extracting minerals involves a four-step process: blasting, excavation, removal and initial primary crushing. Open pit is mined using a combination of excavator dump trucks and shovel dump trucks. Ore is removed from a series of benches which are linked to the top of the pit by a 40 metre wide trench road. Each truck transports around 290 tonnes of excavated soil and ore to the top of the pit where it is stockpiled or sent to the primary crusher. Hydraulic and cable operated electric excavators (Bucyrus RH 340B and 495HR shovels) are used alongside Komatsu 930Е-4SE dump trucks. A total of 28 dump trucks have been used on site since August 2012.