Frontier-Kemper recently made history again with a new, US record for the largest, single-pass, full-face, Blind-Drilled Shaft. This drilling feat was accomplished on February 20, 2014 with the completion of the South Vent Raise (SVR) at Barrick Gold Corp.'s Cortez Hills' Mine. The North Vent Raise (NVR) was completed in July 2012. The NVR was Blind-Drilled to a 14-ft. diameter at 1,475VF. The SVR was drilled to a 16-ft. diameter at 1,764VF.
The NVR originally was to be concrete-lined but was changed to steel lining at the owner's request. This required 148 pieces of steel lining to be installed using a gantry system. The NVR is the first, blind-drilled, steel-lined shaft in this region of the US.