What is the advantage of using a decline over a vertical shaft to access an ore body?
Typically, declines are used to access ore bodies that are located less than 1,500 feet (ft) in depth and shafts are used to access ore bodies that are located more than 1,500 ft in depth. As a mine gets deeper and haulage distances get longer, more trucks are required to haul ore up a decline to achieve the same mine production rate. However, a point is generally reached when it is more economical and productive to hoist ore up a shaft, rather than using a decline, and that depth is typically at about 1,500 ft below the surface. In addition, shafts also allow personnel to get to their workplaces more quickly in deep mines than by using a decline. The disadvantage to using shafts is that they require that the mine be developed at discrete levels. This means that equipment is then “captive” on one level and requires that it be dismantled, moved either up or down the shaft in pieces, and then reassembled on another mine level. These activities are also expensive and result in poor equipm
