The Democratic banner. (Mt. Vernon, Ohio) 1898-192?, 1914-03-03
OF Railroad Trains By A
New Brake
Successfully Tried Out By
Pennsylvania Ry


system proved 1t possible to stop a
train of IL steel passenger cars and a
locomotive, all weighing nearly 1000
tons, within 1000 feet, or the length
of the train, when running at a speed
of 60 miles an hour. The momentum
of such train running at that speed
is equivalent to that of ton weight
falling from a height of 81 miles. The
energy developed corresponds to that
of blast of dynamite sufficient to
blow the same train 120 feet into the
air. With an emergency application
of the highspeed brakes In general use
the same train could be stopped in a
distance of 1000 or 1900 feet.
S. w. Dudley describes the new sys-
tenn In paper prepared for the Amer
lean Society of Mechanical Engineers.
The apparatus is operated with either
pneumatic or electrical control, and
not only requires less expert manipu-
lation, but makes it possible for an
engineer to control his train by ordin-
ary service applications of the brakes
for slow-downs or station stops with.
out shock and with greater accuracy.
The improvement has been obtained
by quicker application of the brakes
and by higher pressure, which may
be held until the end of the stop. The
higher pressure is obtained chiefly by
an improved rigging under the cars
and on the trucks, and by clasp
brake having Two shoes on each wheel.
when operating pneumatically,"
Mr.. Dudley 'the new brake shortens
the time of obtaining maximum emer-
gency brake cylinder pressure on the
train as while from seconds with
the present high-speed equipment to
35 seconds, and with electrical con
troll this is again shortened to 2.25 sec
onds. Moreover, 1876, 150 and 1870 pes
cent emergency braking power Is
available, as may be thought desirable
or found permissible, according to cir
cumstances when the installation is
made. The present higb-speed equip
ment has an average of 100 per cent
Using 150 per cent emergency gralt
ing power, the quicker and more pow
erful pneumatic emergency applica
tion shortens the stop at go miles al
hour from 1000 feet to about 1,40O
and the simultaneous action of elec
tri-pneumantic brake still further
shortens the stop to little more thar
1000 feet.
"a train OF II steel cars and loco
motive with the electro-pneumatlC
brake 15O per cent braking power
clasp brake rigging, uuHanged brake
shoes, can be stopped as follows
From 80 miles an hour. In 200 feet
equivalent to an average retardinl
force of 800 pounds per ton
From 60 miles an hour in LOOT
feet, equivalent to an average retard
ing force of 24O pounds per ton.
From 80 miles an hour. in 1900
feet, equivalent to an average retard
ing force of 2t4 pounds per ton
with the presentday high.speed air
brake equipment the attempt to max,
an emergency application during th'
progress of or before releasing ser
vice application will produce only thu
same stop rs if merely q full service
application had been made Consider
ing the ordinary full service stop iron
60 miles an hour within say 2,000 o
1900 feet, as 100 per cent with the i'm
proved apparatus, operating pneumat
lcally, an emergency application fol
lowing a partial service application
will shorten about IA per cent ant
after a full service application abou
10 per cent with electrO-pneumatic OF
Grafton the gain is 20 per cent and
per cent respectively his IL a safet
factor Of great Importance.
Shocks or jerking among cars O
the train during brake application ar
due to slacken action modified b.
speed as shown by pneumatic an
electro-pneumatic stops from both hig
and low speeds. At high speeds 6
to 80 miles an hour, the serial actio
of the pneumatic emergency applies
tion resulted in noticeable shock
which increased in severity at lowe
speeds, and ut 10 miles an hou
amounted, in effect, to collision be
tween the rear and forward end of tn
train, the train being stopped In 4
feet. The simultaneous application O
just as great retarding forces by tn
electro-pneumatic brake entirely elm
Vnated violent slack action at al
soeeds, the stop even at 10 miles a
hour In 81 feet being without shock,
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