Since 2012, Barr has been providing engineering, design, and on-site construction support services to Nevada Copper for development of its Pumpkin Hollow underground copper mine and portions of the surface processing facility near Yerington, Nevada, about 75 miles south of Reno. Although design began in 2012, it was paused for several years and was nearing completion in 2022 when the operation went into care and maintenance mode.
Barr started out providing electrical design for a temporary sub-station, temporary hoist house, headframe, and collar house for the east shaft at the Yerington facility. Barr designed a temporary 10 MVA substation for the hoisting and underground operations and redundant underground power distribution at both 13.8 kV and 4.16 kV as well as 480 V. Power distribution supports critical systems such as dewatering, ventilation, and mining operations.
A second phase of the project led to Barr providing a third-party review of the client’s deficient paste plant as well as new engineering work and portions of the detailed electrical design for both underground and aboveground permanent power distribution for the project’s east-shaft area development. Our work entailed mechanical and structural design, updated process flow, power distribution, electrical equipment layouts, PLC control, grounding, lighting, switchgear, communications system, dewatering system, and fiber optic networking.
For the paste backfill portion of the project, we provided engineering services to upgrade and retrofit the newly built paste plant to correct issues that prevented plant operation; the paste plant was designed and supplied by another firm. Upgrades included changes to the binder addition system, adjustment of the conveyors, modification of the tailings hopper, and functional changes to the control system to make the system operable. We performed the engineering and managed the construction of modifications. Barr was in the process of commissioning the plant when operations halted.
Barr also provided engineering services for the overall site plan, headframe, bin house at headframe, hoist and UG substation, hoist house, compressor building, and vent shaft.
For the underground and shaft portion, we provided engineering support for steel, mine dewatering, shaft services, loading pocket, ore and waste bins, rock breakers and grizzlies, crushers and conveyors, shaft station fit out, maintenance shop, refuge station, warehouse and offices, mine ventilation, and mine automation and communications.
Next, Barr provided surface engineering drawings for expanding the hoist house to protect the project’s service hoist, as well as for hoist controls, an electrical room, and mine control facilities. The processing facility of the Pumpkin Hollow underground mine has commenced production using development ore from mine construction, and the underground mine itself began production before the end of 2020.
Barr has provided on-site construction oversight for the mine's electrical infrastructure and aboveground mechanical systems. This has included full-time on-site presence by members of Barr's electrical and mechanical engineering team to provide additional electrical design and start-up and commissioning support, as well as construction observation and management services.