The silver state. [volume] (Unionville, Nev.) 1870-1903, 1902-01-09
THE AIR BRAKE.
Information Concerning the Workings Of This
Useful Appliance.

1
The automatic air brake, now in gen.
eral use on all the railroads of the
country, gives the engineer almost
perfect control over engine and train.
1t Is interesting to note that while they
are operated by the direct application of
compressed air, the engineer in his cab
sets !" the brakes by reducing the
air pressure. Underneath every car
equipped with air brakes is a pipe CAL
led the train pipe" These pipes are
connected together, when the train is
made up, by flexible rubber hose Sc
that the train pipe is continuous from
it's connection wit hthe locomotive to
the last car. The train pipe connects
the main compressed air resery ir on
the engine with the car reservoir. The
air pump stands vertically on the en-
gine in front of the cab. When the car
brakes are "off" there is from seventy
pipe and car reservoirs.
Each car reservoir is connected by
a pipe with the brake cylinder in
which is the piston which actuates the
levers that apply the brake shoes to
the wheel . In the system of pipes be-
tween the car reservoir and brake
cylinder is in an ingenious device called
the triple valve.'f Passages in this
valve admit the air to the brake cyl
inder. the car reservoir. the train pipe
and the open air. The piston in this
triple valve is the key to the whole
situation. When the train is running
freely with the full pressure of air in
the train pipe, and the car reservoir
there is no compressed air in the brake
cylinder. This is because the piston
in the triple valve is balanced; the
pressure is the same on both sides OF
It,
But when the engineer. to slack
speed opens the engineers valve in the
cab, he let's air out of the train pipe;
the piston in the triple valve out OF
balance. In doing this the piston
moves, opening a passage which leads
through the triple valve from 1he cal
reservoir to the brake cylinder. The
compressed air rushes from the reser.
voir TO the cylinder and moves forward
the piston in the cylinder, nd thus tbs
brake is set
To release the, brakes the engineel
valve a certain way and air from .h'
main reservoir is admitted to the traii
pipe. This makes the pressure in TIL,
train pipe greater tnan the pressure
in the car reservoir. and again the pis
ton in the triple valve is moved. open
ing communication from the train pip'
to the car reservoir so as to recharg,
1t. and at the same time an opening /!
exposed which let's the air escape from
Thus the car reservoir is rechargeo
and the brakes are released by the sim
Pile operation of admitting air to the
train pipe.
| The engineer can set the brakes grad
ually by reducing the pressure in the
train pipe gradually. II he wishes tc
make an emergency stop he throws
the handle of his engineers valve to
the emergency position. This permits
so much air to escape from the train
pipe at once that the piston In the
tiple valve is violently moved to
one side. opening a large orifice so as
to admit a great deal of compressed air
to the brake cylinder at once, and at
the same time admitting air to the cyl
inder from the train pipe direct.
1t is when the handle of the engi-
neer's valve reaches the emergency po-
sition that passengers are pitched for
ward and the car wheels complain with
nerve shaking groans and screeches.
In making a service stop a skilled en-
gineer can bring his train to a dead
pause so gently that passengers must
look from the windows to fully realize
that the train is motionless.
.