To reduce human drudgery and to improve safety & productivity, SCCL has planned
to gradually phase out Conventional Bord
and Pillar method and to replace the same with Semi-Mechanisation.
The “Coal cutting machine-Gathering arm loader - Shuttle Car” system of
mechanization along with belt conveyors for development of seams was
successfully used by SCCL from the late 40s to the early 70s.This system of mechanization was not
adaptable for depillaring operations and therefore found only limited
application in development of flat seams.
Side-Discharge-Loaders (SDL) and Load-Haul-Dumpers (LHD) which combine the
operation of loading of coal at the face and transport by belt conveyors became
available.SCCL introduced these
machines in the years 1978 and 1979 respectively. LHDs are in use for
mechanized depillaring operations since 1983.
SDLs and LHDs need gradients flatter than about 1 in 4 and 1 in 6 respectively for
efficient operation and in view of the limited deposits with such gradients,
application of these machines are not extended to all the underground mines.
During 2011-12, the production from
SDLs & LHDs was 4.813MT & 1.760MT respectively.