Tender for Optical Fibre Cable Protection works in - Northern ...

DGMM-KP/Protective work/Tender-08(II)/2012-13
responsibility of the holders of the license for the proper use of explosives,
its transportation and storing.
d) Method of using :
The safest explosive is the Gilatine and electric detonator. Gilatine is in the
form of a stick. Electric detonator is a type of fuse used for firing the
explosive electrically. Holes are made at suitable intervals on rocky terrain
or boulders either by air compressor or by manual chipping.The depth of the
holes should be 2 to 3 ft. Fill up the holes with small quantity of sand for
about 6”. First the electric detonator is to be inserted into the Gilatine and
the Gilatine is to be inserted into the holes keeping the + ve and- ve wirings
of electric detonators outside the holes. Again refill the holes with sand.
These +ve and-ve insulated wires of detonator are then extended and finally
connected to an EXPLODER kept at a distance of not less than 100 m.
Now the explosive is ready for blasting. But, before connecting wires
to exploder for blasting, all necessary precautions for stopping the traffic,
use of red flags, exchange of caution signals, etc. , should be completed
and only then Exploder should be connected and operated.
e) Operation of exploder (IDL schaffler type 350 type exploder ) :
The type 350 blasting machine consists of a bearing block with blasting
machine system and the explosion proof light- alloy injection molded
housing. The exploder is held with the left hand. The twist handle is applied
to the drive pin, clapped with the right hand turned in the clock wise
direction in continuous measurements at the highest speed from the initial
position until it reached to a stop. At this stage an indication lamp will glow.
When the indication lamp glows, “press button switch” should be pressed.
This will extend the electric current to detonator and Gilatine will be
detonated. The rock will be blasted out of the trench. Number of holes can
be blasted in a single stroke by connecting all such detonators in series
connection and finally to the exploder. After blasting, again mazdoors are
engaged on the work to clear the debris. If the result of the first blasting is
not satisfactory, it should be repeated again on the same place.
f) Warning :
There may be two reasons for unsatisfactory results of the blasting :
Misfire of Gilatine due to leakage of current from detonator.
Over loading because of overburdens.
Never pull the broken wire pieces form the holes in such cases. Attempt
should not be made to re blast the misfired Gilatine. The safest way is to
make a fresh hole by its side and put fresh Gilatine in that hole and blast it.
g) Precautions :
The abstract of Explosives Rules 1983 which are relevant to our work is
given below:
85 Signature of Bidder with seal