The daily sentinel., 1907-06-18

4 We read of accidents and collisions
on railroads and the press has stated
I that on more than one occasion the
engine was found with the throttle
| closed and the airbrakes set. Again
how many times we are told that the
engineer applied the air and stopped
the train just in time to keep from
ging into river where a bridge was
washed away or, in going over a
mountain road, large rock has come
! down onto the track, and the train
/ had to be stopped to keep from run
ming into it. Yet. how few of us un-
| derstand anything about this wonder
/ full piece of machinery wonderful
because this appliance has made tray-
cling safer than formerly.
If it were not for these air-brakes.
we would not be travelling over the
country at the rate of sixty miles per
hour. for there would be a very small
chance of stopping in time in case of
an accident, if the engineer had to de-
pend upon the brakeman to stop the
train by setting the hand brakes as
in the past.
The equipment for the air brakes
consists of an air pump on the en-
gine, which pumps air into a large
steel reservoir, also located on the
engine and an air valve. called the en-
gineer's valve, and located at con
venient place in the cab OF the en-
Eine. so it is handy for the engineer.
In fact. it Is so arranged. on most
mountain roads at least. so the engi-
neer can stand with one hand on the
throttle and the other on the air valve
The equipment for the car con-
sists of an air pipe called the train
line, running from end to end of the
car, valve known as the triple
valve. the brake cylinder in which
the air is forced when the brakes are
set. and a small steel reservoir. CALI
ed the auxiliary reservoir, in which
air is stored until it is ready to be us
ed in the brake cylinder
All the air that goes into the auxil-
iary reservoir has to go through the
triple valve and necessarily it all
has to return through the valve in
order to get out and into the brake
cylinder
Now consider the train line the
auxiliary reservoir and the main res
eryoir on the engine, TO be full of
air at the required pressure, which is
about seventy pounds per square inch. ,
and that the engineer wishes to stop
the train; the action of the brake
equipment is as follows The engi-
line, which he can do by putting the
engineers valve in a certain position,
and by doing so the pressure in the
auxiliary reservoir, under each car is
more than the pressure in the train
line and this acts on the triple valve
causing It to change its position, and
allows the air from the auxiliary res
ervoir to go through a different pass
age through the triple valve, to which
1t Travelled in getting to the auXil-
Hilary. and by this passage it finds its
way to the brake cylinder. Thus the
pressure increases in this cylinder.
and by a system of levers and brake
beam, with the iron shoe. Is forced
against the face of the car wheel and
as this action Is the same on every
car, the train comes to quick or
slow stop, according to the amount of
air released from the train line, at
the option OF the engineer.
Now when the engineer wishes to
release the brakes, he moves the en-
gineer's valve to a different posi-
ton, and this let's the air from the
main reservoir on the engine pass in
to the train line again, and brings
that pressure up to the usual seventy
pounds as before; and by this action
the triple valve under each car is
again changed. allowing the air to go
from the train line into the auxiliary
reservoirs under the different cars
At the same time. and by the same
movement of the triple valve letting
the air that is in the brake cylinder
escape to the atmosphere, through
another opening thus releasing the
/ brakes.
On mountain roads where the brab-
\ es have to be on partially all the
/ time. when going down grade, there
| Is a special valve on the brake cylin-
der that will not allow all the air to
escape to the atmosphere when the
brakes are released, but will keep a
small pressure Of from five to ten
\ pounds always in the cylinder
The students in the senior class in
the mechanical department Mt the
4 State Agricultural college, have an
n opportunity to study and investigate
and acquire thorough knowledge
of this interesting apparatus, as the
II department has among its numerous
mechanical devices in the engineering
laboratory a complete Westinghouse
, air brake equipment
f. n. LANGRIDGE.