The Washington herald. [volume] (Washington, D.C.) 1906-1939, 1915-08-28
Choice Does Not Dictate the Selection
of Methods and Design in the

Choice Does Not Dictate the Selection
of Methods and Design in the
Production of Such a System.
I that the art of signaling has developed
| into a highly specialized branch of tnGi
neering, and that there is perhaps n,
more difficult undertaking than to devise
| a highly organized and specialized I-ece
| of apparatus for employment with sane
| ton and success in the art Of railway
signaling because it is not simply a cues.
| ton of constructing the means requir ed
| that will work and contribute the me-
chanical and electrical benefits sought
with precision, but the crucial test of the
ability of such an invention is that II
must strictly observe certain Engineering
Rules (The Ten Commandments of Sig.
naling). which result in laying down a
technical process of action, operation ard
control that is not only of the highest
Importance, but that is very difficult to
attain.
Inasmuch as a signal system depends
for its approval and adoption upon a cor
rect theory Of mode of operation, which
is based primarily on the observance OF
the Engineering Rule of Failure on the
Side of Safety" attention will be briefly
directed to the operative side Of the in
The Ideal Method of Operation.
The rationale of operation of the Buell.
system may be explained by referring to
the simple process or electrical mode OF
operation of the very perfect electrical
contrivance known as the Automatic
Block Signal System, in which three SIM
pie steps are involved in the range of
electrical action thereof, to wit: An in
terruption of current in the track circuit
causes an interruption of current in the
control circuit which in turn causes an
interruption of current in the working
circuit, and the consequent production of
a danger signal on the post.
This principle of operation is a control
ling principle and one that has been au-
thoritatively and decisively established.
and which has long since won the ap-
proval of the signal world, as II has been
employed extensively in constant practice
for thirty years. To make any true ad-
vance in the art of Cab Signaling and
Automatic Stops. this plan of operation
must be adhered to-
Mr.. Buell. juctifies the existence of his
system and his claim to leadership in this
art for the reason that he advantageously
approached the problem of producing n
satisfactory Automatic Stop by propagat-
ing the best that had been known in the
art by adopting exactly the same mode Of
operation. Thus the Buell. system is the
only one yet devised that shows its fit
ness to meet the supreme engineering
test in this art
The direct advantage Of the Buell. idea
of obtaining connection between the track
and the locomotive, which will be pres
emily referred to. made IL possible to
adopt such a method and reproduce such
an ideal.
To illustrate practically a hampering
condition imposed by the strict adherence
to such mode of operation when ap-
piled to a cab signal. let us briefly refer
TO the matter OF Illuminating the signal
lamps in the cab of the locomotive under
danger conditions.
As the signal lamps are included in the
working circuit. and as that circuit must
be actuated by reason Of its interruption
or breakage some way must be devised
to accomplish the seemingly impossible.
TO wit: The lighting of electric lamps by
opening a circuit. and paradoxical as this
may seem, Mr.. Buell. has applied the in
genious method OF opening or breaking
an electric conductor in one part Of the
working circuit to cause a failure Of cur
rent at that point Ito effect the release
of air from the brake system) and to eff
feet the shifting of the current to the
lamps in another or parallel branch of
the working circuit to illuminate the
lamps from low incandesence to full
brightness.
Furthermore. such mode Of action In
the Automatic Block Signal System de-
ponds upon slow-acting instruments. while
the attainment of such a mode of opera
ton with respect to the travelling loco
motive imposes the necessity of employ
ing duick-ac..ls means, to this end in the
Buell. System the governing instrument
was designed to have a capacity to re-
spond TO a change Of condition on the
track. in a two hundred and fiftieth OF a
second.
Thus II can be seen that such a trans
position Of method from a roadside signal
post to a travelling locomotive requires
not only striking ingenuity and origin
atty of conception, but it stands as a
asting tribute to the foresight Al All.
ity of its author.
Other Indispensable Factors.
technical details regarding the produc-
ton OF such a system, except to say that
the chief mechanical difficulty presented
In the Automatic Stop Problem. and which
goes to the very heart of the matter is
to devise an efficient way Of establishing
operative connection between the track
and q travelling locomotive, that is thor
oughly reliable and practicable.
Therefore, the next essential fact which
gives pre-eminence and value to this sim
pie. inexpensive and efficient system IL
the manner Of obtaining q rolling wheel
contact by the tons Of weight of the loco
motive through the pressure Of the wheels
on the naked traffic rails because II is not
only the acceptable manner OF obtaining
contact. but It requires no development on
the track experimentally or commercially
as II enables the Buell. System to utilize
what 10 already there without change.
Furthermore. II dispenses with m. .hai.-
icaily operated third rails and ramps and
all the varieties Of Impossible and irn-
practicable extraneous and expensive
equipment. and the radical changes IN the
t-asx that they would necessitate ana
which are in themselves q source of dun
ger greater than their protective value