The Plymouth tribune. (Plymouth, Ind.) 1901-1911, 1909-11-18
STOP! LOOK! LISTEN!
A TALK WITH THE SIGNALMAN

How asout the single track?" The
automatic Arrangement is the same. only
there is a signal at each end
isn't it a possible thing for n train
to enter a single track at one end on
the same instant another enters at the
opposite end? What them
HeS-but we have that taken care Oh.
On double track. a train through the
signal talks only to the train behlnd.
ON the single track il not only talks
back. but also to one which may be com
ing from the opposite direction. rms II
done by the current overlapping from
one block TO the next Before the en-
trance to Il sngle-track block is reached
the train sets a stop signal at the far
end OF the block it is about 10 enter.
And as it enters the block it also sets
the entrance signal to stop, just as is
done on double-track.'
How does an engineer know before ne
sees the home arm what ii will siSnal
we put up another signal from half
mile to mile from the entrance TO a
biock-in the direction from which the
train approaches. IL is called Distant.
The one at the entrance is called the
Home signal The distant indicates the
position of home signal, see?'
rs the distant distinguished from the
home signal to aid the engineer
Yes, the Distant is painted Yellow
with black bar, and has a forked end :
the Home red, with white bar and
square end"
is displayed only when something occurs.
Anything but trains occur?"
Now you touch the most important
feature of the oatfit, and the principal
reason why the arm is made so that
when left to itself it will stay firmly
at stop As it is constructed it cannot
show anything but stop, unless the entire
combination of rails. wire, current, mag
net. etc., are working perfectly II a
wire parts. rail breaks. a battery falls,
switch point opens the slightest, then
the combination fails. the arm is released
and resumes horizontal position. The en-
gIneer knows you see when signal says
stop; there may be n train, an open
switch, break in the track or in the
signaling apparatus"
What is done at night. when the
semaphore arm cannot be SEEM"
Lights of several coiorS are used on
these same posts. These are seen through
spectacles in the butt weighted end
of the arm, and are displayed and OBJ
scured, according to the signal"
"Why the name spectacle?'
That's what it is. The light is white
or ordinary flame color. supplied by an
eight-day lamp. 1t will burn eight days
without replenishing. although all lamps
are refiled every four or five days. Wher
the home signal is in stop position, the
engineer sees the flame through RED
glass. That's stop. and it is used only
| in the home signals Ia distant sigma
| is at caution he sees through yellow
Sidss- 1SlioW Is used oiii5 III ,iic ~
| signal. 1t tells the engineer it is the
| distant, and to be prepared to stop al
| the home signal. He may see through
green glass. That means proceed. ano
| is used i'm 10th home and distant signal
what does a white light mean?
| well. it is so easy to have we don
| dare use 1t. AS white light on soma
phore can be displayed by breaking spec
| tacle glasses. you can understand why
! it Is impossible in our scheme"
How about places where two or more
| lines cross at grader"
The general principle. movements 81
! arm by day. and coors OF light III night
| are the same. but being greatly compli
| Gated all signals are controlled by lever.
| operated by men from IL central station
| The crossing and contiguous tracks art
| governed by the Interlocking system.
"When in perfect order and unoccu
| pied ii displays stop to every track APP
| preaching the crossing. The block. yol