Evening star., 1913-10-06
Absolute Necessity
of Signal System.

Absolute Necessity it's investigations
and drew its con-
of Signal System. clusions it laid
down as the one absolute necessity OF a
safe train stop that it should be so de-
signed that the breakage or removal OF
the stop from the roadside should cause
an application Of the brakes In one ap-
paratus of this kind this object Is &C
complished by having rigid member SO
securely fastened to the track as to be
as little susceptible to breakage or re-
moyal as the rail itself This rigid MEM
Der comes in contact with a lever on the
engine, which causes the valve Of the air
brakes to be opened. and, when I'm normal
position, 1t strikes this lever on every
train that passes It is in this position
at the entrance of a train to each block,
if the signals are set at stop, or IL the
block section is obstructed. If. however,
the fixed signal is set at proceed. or
the route is clear the movable roadside
member goes into operation In q way TO
strike another lever, so as to close the
valves of the air brake, and thus nulihes
its action in striking the former lever. In
this way it is operated every time train
passes, and therefore, must always De
kept in condition.
Most automatic train stops are only op-
Grated when an emergency stop Is made
or when periodically tested. and are thus
more In the category of life preservers
and fire extinguishers-used only in emer-
gencies, and, therefore, not likely always
to be in operating condition.
One of the most extensive EFFORTS In the
perfection of an automatic train control
system that has been made Is being
worked out by an inventor OF Sydney,
Australia. He bought a piece OF old dis
used railroad and laid two miles of new
track on it. He then bought two engines.
Laying of the two miles of track INTO
three sections, with a. signal Dox between
each two sections, he proceeded TO put
his system to the test. He has an ar
rangement whereby he can not only stop
a train, but which permits him to choose
between the trains which he will permit
to enter a block at either end. BY
system of electric wiring and system
of third rails he can communicate from
the signal tower to the engine cab, and
there tell the engineer both by visual
and audible signals whether or not he
can proceed There are two sets OF
whistles and light in the cab. If the
train is to stop and the engineer falls to
stop it. there is q chorus of two shrill
whistles and a red light in his cab, and,
If he still falls, an automatic stop re-
leases the air and sets the brakes on his
train. A recording apparatus makes
record of his failure to comply with the
signals. The automatic stopping appa-
ratus is so arranged that it will only al
low a train to pass 1t when it is in per-
feet condition and when the signals by
the roadside say the way ahead is clear.
One of the automatic stop devices
brought out in the United States con-
sists of
Opens Air Brakes roadside de-
Unless Way Is Clear. AZ tbs light
of the track in the direction Of traffic.
which engages a lever attached to the
pilot beam of the locomotive when train
is to be stopped. It consists of two f1ex-
ible blades attached to vertical shaft,
which Is free to rotate. A pull of five
pounds at the end Of these blades Is
necessary to turn the shaft quarter Of
a turn The lever on the engine opens
the valves of the air brakes and stops
the train Whenever the signals by the
roadside are not set to indicate a clear
track the contact arm at the roadside
must always stand in position to stop
the train. The only condition under
which it can permit a train to pass Is
when the signals are thus set. AS 1t Is
securely linked with the block signals,
the engineer cannot, under any circum-
stances, run past q danger signal
A number of American railroads have
been experimenting with this and other
types of automatic train stops. and these
experiments are gradually bringing about
one Improvement after another. None of
them has been so perfected as to lead to
its adoption by any railroad, but it is ex-
pected that several railroads will. In the
not distant future, try some OF them out
under actual operating conditions. The
New Haven has offered very large prize
for a really practicable system. A num-
ber of these systems, when tried out on
short stretches of road, have failed to
give the results theoretically promised,
and there have been some wrecks where
they have been used.
i
Automatic-train control however. is no
new thing In Europe. At least two rail-
roads In Eng
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