coal trade bulletin - Clpdigital.org

and of fuse, and there have been cases where an
injured fuse burned almost instanteously Chiet
among the causes are abrasion, blows, or too great
pressure. Therefore, in addition to informing the
miner as to the normal burning rate of the fuse,
see that fuse is in good condition when taken into
the heading and that it is handled properly after
it gets there.
See that the fuse is properly stored, for a large
percentage of the accidents from misfires aie
traceable to fust that has been damaged in storage.
Never store fuse near boilers, steam pipes.
or other sources of heat where the temperature
is apt to be high. Exposure to heat causes a
marked retardation in the burning rate. Never
store fuse in a cold place. Cold fuse is dangerous.
because cold often causes fuse to crack when being
handled, so that misfires result. Keep fuse dry.
It is very difficult to dry out a powder train that
has become damp, and when the fuse burns the
dampness will be driven ahead of the fire in the
form of steam, so that, even if it does not accumulate
in sufficient quantity to
(.TJEXCH THE FIRE
in the fuse, enough of it may be driven into the
detonator to prevent that from igniting and thus
cause a misfire. Always provide a. dry place with
an even temperature for the storage of fuse.
Do not delay installing adequate ventilating
equipment when harmful accumulations of natural
gases are encountered in the tunnel. This is particularly
important when such gas forms explosive
mixtures with air. In the latter instance, see
that none but safety lamps or their equivalent are
taken underground and that sufficient air is provided
to dilute the gas enough to make it harmless.
Prohibit the men from riding on loaded trips,
ancl whenever possible provide special cars, either
propelled by hand or drawn by a mule or motor.
for their use. Do not peimit the men to jump
on or off moving cars.
If there is a trolley wire or other electrical
apparatus in the tunnel, see that the men are instructed
against the danger of shocks and do not
allow them to carry tools on their shoulders when
passing in or out. Instruct the men, and especially
the foremen, in the proper methods of resuscitation
in case of electrical shock. Methods for
the treatment of such cases are given in detail
in Miners' Circular 5, published by the Bureau of
Mines for free distribution.
See that combustible rubbish is not allowed to
accumulate in the vicinity of buildings or timbering
and that the supply of hay is properly protected
from fire. Do not construct any wooden
buildings nearer than 200 feet to the mouth of
the tunnel unless they are absolutely necessary.
THE COAL TRADE BULLETIN. 31
In such a case provide a separate exit from the
tunnel at least 200 feet away and arrange a fire
door so that the regular exit may be closed from
a distance, in order that the men in the tunnel
may not be suffocated by smoke and gases in case
the buildings take fire. In either case provide
for a water supply adequate for fire protection,
with hydrants and hoses suitably disposed about
the several buildings.
Exercise great precaution in driving toward a
place where you are likely to strike a flow of
water that may carry with it a rush of mud, sand,
gravel, or other debris. In such cases it is advisable
to drive a drill hole at least 20 feet in
advance of the heading to give warning of the
danger before the body of water is broken into by
the full head of the tunnel.
Upon you, the foreman, falls the work of seeing
that the superintendent's orders are obeyed, and
your duty to care for the safety of the men and
to see that they use the proper precautions in
their work is even greater, if possible, than his.
For you are daily in close personal touch with the
men and are the man to whom they naturally look
for instructions and guidance. If you will observe
the following precautions, you will be better
able to fulfill your responsibility for the life ancl
safety of the men under you.
The common practice of overcharging shot holes
is one of the chief causes that combine to make
falls of rock from the roof by far the greatest
source of danger in tunnel work. Extremely
heavy charges shatter ancl crack rock that ordinarily
would stand without risk of falling and
thus render it highly dangerous to the men working
underneath. Of course, it is essential to efficient
work in tunnel driving that the blast should
completely "break bottom" without any need for
a second charge; still you should see that the
smallest quantity of dynamite that will do the
required work is used, at least in the holes near
the roof. niconomy of explosive demands this,
everything else aside; but you should also realize
the dangers of the heavier charges and, when they
are necessary, you should take extra care along
other lines for the safety of the men.
Do you go yourself or permit the men to return
to the face after shooting a round, without thoroughly
testing the roof just exposed by the blast?
Neglecting to test the roof is another great source
of accident. Upon reaching the heading after a
blast, detail at once as many men as may be
necessary to clean down thoroughly all the loose
pieces of overhead rock. Encourage the men to
report to you all parts of the roof that seems to
them unsafe. See that any loose piece of rockis
either pulled down at once or properly supported,
and never take any chances by postponing
the work of timbering, regardless of how pressing