HVO uses dragline and truck and shovel methods, and is operational 24 hours a day, seven days a week.
Coal is loaded using a combination of loaders and excavators with haulage to the ROM hopper undertaken using rear dump trucks. The operations are supported by additional equipment including dozers, graders and water carts.
All pit end-walls have benched and battered designs based on the existing operation with allowances made for increasing depth of mining. The design provides for mining roadways and catch benches.
Coal loss and dilution factors are also applied and vary by the equipment type uncovering the various coal seams (i.e. excavator/truck versus dragline). Typical roof and floor coal loss thickness ranges from 5-25cms. Typical roof and floor waste dilution thickness ranges from 3- 7cms.
HVO comprises three separate previous mines namely Howick, Hunter Valley and Lemington Assets which included the following:
- The Lemington Mine, which began production in 1971, was acquired and merged into HVO in 2001.
- Coal production began at the Howick Coal Mine in 1968 in what is known as the West Pit at HVO. In 2000 the Howick Coal Mine became part of Rio Tinto's Hunter Valley Operations as a result of the merger with Hunter Valley Mine.
- The Hunter Valley No. 1 Mine began production in 1979.
The HVO site area is approximately 20 km long (North to south) and 10 km wide. HVO is divided into HVO North (HVON) ........
