The Birmingham age-herald., 1913-04-18
NESb|TT EXPLAINS
SEVERAL CAUSES Of
MINE EXPLOSIONS
Large Per Cent of Mine
Horrors Occur During
Spring Months
FEWER ACCIDENTS
IN 1918 THAN USUAL
Dust Explosions Caused by Unequal
Temperatures and Barometric Pres
sure on Outside Play Important
Part in Preventing Explosions


the conditions which make what is COM
monty known as the mime explosion sea-
SON. of the year. We're very Interestingly
given yesterday by C. Fl. Nesbitt, state
mon knowledge that very large per cent
of the horrible mine explosions of the
past in the Alabama coal mining district
as well as other districts have occurred
in the spring of the year, usually in late
March, April and May. Nearly all these
explosions in the Birmingham district
which have claimed enormous death tolls
have occurred during one of these
months
Fewer Accidents This Year
Mr.. Nesbitt is a man thoroughly conver-
SAINT with all sides and phases of the min
ing industry. knowing the scientific and
basic principles behind all effects. His
knowledge of the causes of mine explo-
sions, their prevention and how to combat
peculiar and special conditions, met with
at various times in this underground in
dustry, has had practical results. This
year there has been fewer mine accidents
in this state than for many years past,
the remarkable record having been made
by the Tennessee Coal, Iron and Rail-
road company of but one fatality in three
months in all their mines and this man,
according to all evidence, was killed
largely through his own negligence. 1t
is stated the mine accident season this
year is well past now and that no serious
accidents are looked for this spring.
THE fact that so many mine explosions
occur in the spring months is due to sew
eral different causes, but one or two are
most important and when attended to-,
those remaining are not of enough weight
to cause danger" said Mr.. Nesbitt.
The first thing to consider about the
prevalence of explosions at this time of
the year is the fact that the temperature
of any mine remains at all seasons of the
year at anywhere between 50 and 60 de-
grees, averaging 81 or 62 the year around.
Now, there are two seasons of the year
at which the outside temperature must
pass this inside temperature, or, in other
words, equal it for a certain length of
time. In the winter the temperature of
the outside air Is much lower on an aver
age than that inside the mine AS spring
approaches, the outside temperature rises,
and along about April and May it reaches
the same degree as the stationary temper
ature ON the inside
Dust Explosions
Now, this air being pumped through
the airshafts of the workings does not
condense expand, as it undergoes no
change in tempera ture, and therefore it
is of a lower degree of humidity than
at any other season of the year. This
makes the mine dry. dust accumulates
and unless yer yefficient -dampening de-
vices are used inside the mine, an explo-
sion is liable to occur,5 being what we call
dust explosion. Then during the sum-
mer this outside temperature goes on up
and is well above the inside temperature.
This warm air being pumped into the
colder air of the mine is condensed and
contains more moisture than at any other
season, making this the safest season OF
the year for mining opera ton, if natural
conditions be considered.
1.-The second important condition bear
ing on mine explosions at this time OF
year is the barometric pressure on the
outside of the mine. The gas which Is
liable TO be tapped at any time in the
workings of a mine offers a certain pres
sure against the Walls OF the rooms and
shafts. This pressure is counteracted by
the pressure of the air inside the mine.
The average barometrc gage of the year
is about 80 inches in this section and this
air serves a pressure of over IA pounds
against the wall of the mine workings and
against the breaking through of gas. If
the barometric pressure is lowered as il
often is at this time of year. the pressure
ON the inside of the mine is lowered and
consequently gas escapes into the mine
more freely, permitting conditions to arise
favorable to what We call gas explosion.
These same two conditions exist to
some extent in the fall when the outside
temperature is lowering and again passes
the inside temperature. but at that time
1t does not seem to be as effective as in
the spring.
"Of course, the way to combat these
conditions is to use modern mine safety
equipments. which provide for ample
sprnkling of all parts of the mine, insur-
ing humidity and other conditions which
make mining practically as safe as any
other occupation. Accidents in mining are
largely through some ones carelessness
or negligence. just as in all other indus
tries