excavation is a complex job. Lots of machineries are needed for its
construction and to give it a finishing touch. Road header, tunnel
header, cutter head, shields etc are some of the important machineries.
once the tunnel is excavated its roof is scaled which is a difficult
task. Before a new drilling and blasting cycle can begin, appropriate
safety measures must be followed to make the tunnel area safe. Safety is
provided by roof scaling which removes loose rock or tying the rock back
together by means of rock bolting.
A mechanical scaler is used to pry loose pieces of rock from the roof
and sides of the working places. For maintaining roof's integrity, rock
bolts may need to be installed in addition to scaling.
The scaler machine can reach to a substantial height and could move in
all direction along 360 degrees. The scaler is available in two or
four-wheel drive with full safety mechanism for the cab operator who is
secured in a suspension seat with a five-point safety harness. Normally
scaler machine has boom with hydraulically-activated extension cylinder
that allowed the boom to reach a maximum distance.