The Range Front Declines were 19-foot-diameter decline connection tunnels for ventilation and material haulage/extraction passages reaching the lower extents and working levels within the existing and active Cortez Hills gold mine.  Excavation was performed in a fully operational mine, necessitating that Drill Tech align with adjacent mining contractors and client operations. This project served as a pilot program and feasibility study for utilizing hardrock roadheaders in mine development by SEM techniques. Drill Tech mined through a mélange of rock conditions ranging from extremely weak to strong, and drill/blast methods were utilized to break through when massive hard rock formations were encountered.  

Drill Tech constructed final CIP concrete structures within the tunnels and caverns for subsequent mining operations, including fuel bays, wash bays, explosive magazines, ore bins, and electrical distribution centers. These structures will serve as permanent mine infrastructure for long-term use and are critical to underground equipment use and maintenance.  Drill Tech optimized the ground support based on insitu materials, only utilizing what was required for long-term stability of underground structures. Several components of the project were completed through concurrent work, such as multiple-heading excavation, progressing the job to finish three months ahead of schedule.