AGENDA - 33rd meeting of Standing Committee on Safety in Coal ...

o Cut Dumping by shovel-dumper should not be permitted in order to limit dragline
dump height within permissible safe pr<strong>of</strong>ile.
o The interface layer i.e. debris <strong>of</strong> coal dust, fragmented rock, soil mixed with water
should be cleared as far as possible from the de-coaled floor before dumping by
dragline. The analysis shows that the presence <strong>of</strong> the wet interface material
decreases the factor <strong>of</strong> safety. If it cannot be avoided, then, it should be ripped by
blasting.
o The valley in the dragline dump should be leveled to avoid rainwater ponding
between the heaps <strong>of</strong> the dragline dump. The trapped rainwater between heaps
percolates to the lower levels <strong>of</strong> dump. The stability analysis shows that presence <strong>of</strong>
rainwater in the dump decreases its stability.
o The overburden excavated from the shovel-dumper benches should not be dumped
on or near the freshly created dragline dump to avoid further loading <strong>of</strong> the partially
consolidated dragline dump. Ideally, dumping <strong>of</strong> overburden excavated from
shovel-dumper benches should be done at least two cuts away (160 to 180m).
o The final resultant dump slope, after rehandling, should not exceed the angle <strong>of</strong>
repose for the dump material (370).
o Slope monitoring is essential to detect any instability in advance to safe guard
against possible slope failure.
o The dumps should be regularly surveyed to produce up-to-date and accurate dump
geometry.
o Geo-Technical cell shall be constituted in this regard at dragline mine with
dedicated team equipped with sophisticated slope monitoring equipments like 3-D
Scanner / Laser Pr<strong>of</strong>iler / Target less Total Station / Slope Stability Radar to
monitor the dump slope stability.
o Adequate infrastructure to be provided for imparting training on slope stability to
all concerned person employed in the large open cast mine.
2. Lodna Colliery, BCCL
Date <strong>of</strong> Accident: 05.01.09
Number <strong>of</strong> persons killed: 3
About working <strong>of</strong> mine:
Mine is working through four numbers <strong>of</strong> pits i.e.7 Pit for IX/X Seam depillaring, 1 Pit
for VII Seam development and 8 Pit for Pumping in VII Seam and 6 Pit used as 2 nd outlet
and isolation stoppings inspection <strong>of</strong> XI/XII Seam.
Details <strong>of</strong> the Old workings <strong>of</strong> 24 th rise <strong>of</strong> VII Seam, where the accident took place:-
At rise side <strong>of</strong> there was barrier <strong>of</strong> North Tisra workings(last date <strong>of</strong> working-1990)
.There is fire in V/VI/VII Seams <strong>of</strong> North Tisra and continuous flow <strong>of</strong> 45 0 to 46 0 C hot
water was there.
Status <strong>of</strong> inspection <strong>of</strong> the barrier and the old workings: It is unapproachable and
sealed <strong>of</strong>f from North Tisra colliery side and thickness <strong>of</strong> the barrier in VII Seam against
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