Pit Viper Beats the Chill

2008 May 15

Butte in Montana was once one of America’s biggest mining regions. Named ‘the richest hill in the world’, its underground operations eventually extended to some 12,000 miles of drifts. Today it is the Continental Pit mine that dominates the landscape and two Pit Viper drill rigs that feed production.

Underground mining at Butte ceased in 1975 and large-scale open-pit mining began in 1955. The Continental Pit molybdenum and copper mine opened in 1980 and is currently 2,230 metres long, 1,110 m wide and 115 m deep with projected dimensions of 2.4 km by 1.8 km and 244 m deep.

Montana Resources bought the property from Atlantic Richfield in 1986. The company stopped mining in 2000 due to the high electricity costs but resumed operations in 2003.

Every day, 102,000 tonnes of rock are mined from the pit and 52,000 tonnes of ore are milled. To keep the three shovels and 170 and 240-tonne haul trucks moving, Montana Resources uses two Atlas Copco Pit Viper Series PV271 rigs, acquired in May, 2005, to replace four older drill rigs.

In the past, Montana Resources used electric drill rigs, but because diesel provided mobility and convenience with no electric power cables, the decision was made to purchase diesel rigs, says Gary Hayes, Maintenance Supervisor for Montana Resources? mobile fleet.

?They?ve done really well for us,? says Hayes. ?Rig availability for the month was at 94% and the figure for the year to date stood at 85%. The goal for availability is 90%, but staying ahead of the shovels is what counts.?

Epiroc operated under the trademark “Atlas Copco” prior to January 1, 2018.