Heavy equipment
"Mechanized mining" refers to using heavy equipment to speed up the mining process. The first attempt at a mechanized tunnel was around 1975. Referred to as '4250' (level) was collared and connected to the conventional rail drift in 1976. Much of the area was widened, tracks taken out, and a junction was created at 3900 level with three separate tunnels. One tunnel went to a massive repair facility '#7' and garage for servicing underground equipment. In 1979 #1 tunnel, which became the main tunnel, was collared and a new drift created at 4800 level to recover silver at the top of the mine. Heavy equipment including jumbos, various air or electric scoop trams in configurations, rockbolt jumbos, giraffes, shotcrete machines, hyabs, mancarriers, dozers, graders, and jeeps were used. Rockbreakers, downhole drills, fan drills, long hole drills, and TNT drills were some of the equipment used to drill for blasting tunnel faces. As the mining for ore pillars continued, most shops were moved above ground for safety.