Ames crews in Arizona are constructing a run-of-mill (ROM) bypass tunnel as part of an early works package to prepare for construction of Leach Pad 2 at a mining operation. The early works scope also includes 1.5 million cubic yards of earthwork in preparation for the pad.
One of the big wins for Ames at this site is safety. When Ames constructed Leach Pad 1 for this mine in 2018-2020, crews logged 700,000 work hours without a lost time injury. Additional miscellaneous work including this early works package has added another 50,000 hours with no lost time injuries. (Way to go Arizona!)
Tunnel construction includes a 32 x 16 x 165-foot double box culvert and 2,300 linear feet of grading and paving. When complete, light vehicle traffic will be diverted through the tunnel while mine haul trucks, hauling millions of tons of ore, will travel over the tunnel. This will allow the haul trucks to operate safely without having to use flaggers to stop traffic while Leach Pad 2 is constructed.
“With the two truck spreads, we have a 992 loader with our 777 haul trucks, and a 395 excavator with our 773 haul trucks.”
Four experienced crews are on site, with 75 crew members at the project’s peak. This includes two truck haul crews, a concrete crew building the box culvert, and a scraper crew, says Project Manager Dan Kennedy. “With the two truck spreads, we have a 992 loader with our 777 haul trucks, and a 395 excavator with our 773 haul trucks.”
Work began in late 2022 and will continue through June 2023, and as always, maintaining the schedule is critical. Construction of Leach Pad 1 was completed in February 2020, and as of March 2023, about half of the pad remains available. By December 2024, the pad will be full, and Leach Pad 2 will be needed to maintain mining operations without interruption.