Mining contractor Cementation has sunk the deepest mine shaft in the United States. The record-setting #4 shaft at Hecla Mining’s (NYSE: HL) Lucky Friday silver-lead-zinc mine in northern Idaho and plunges 2,922 metres (9,587 ft) below the surface.
The shaft has a 5.5-metre (18-ft) diameter and should be completed with all furnishings and conveyances later this year.
The newest shaft will add 23 years of mine life to Lucky Friday, which has operated for 74 years to date.
The #4 shaft is a winze, which is a vertical shaft that begins underground, which Cementation describes as “an internal shaft that requires the equivalent of a shaft head frame and hoisting system … before excavation activities can occur.”
“Reaching the bottom of the #4 shaft is an accomplishment that the Hecla-Cementation project team should be proud of,” Cementation USA’s general manager of operations Eric Smith said in a release. “The project team not only overcame many technical and logistical challenges, but also maintained an ethos of continuously identifying ways to enhance safety and project performance.”
George Sturgis, Hecla’s vice-president of project development, pointed out that the shaft-sinking occurred during a milestone year for the miner. “Hecla’s 125th anniversary will be celebrated in many ways this year — reaching the bottom of the #4 shaft with Cementation is surely one of the best.”
Cementation is based in Salt Lake City, Utah, and is currently sinking 15 shafts across the globe.