Evening times-Republican. [volume] (Marshalltown, Iowa) 1890-1923, 1907-01-11
AUTOMATIC SIGNALS
) |O GOVERN TRAINS
Northwestern Installing Won
derful System Along Its
Iowa Division
ELECTRICITY CONTROLS SIGNAL
Tho Hall Automatic Signal System,
Will Regulate the Mover ent of
Northwestern Trains Within the
Next Year or Two-The System
Does the Work of Operators.

Within the next year or two North
and along the entire Iowa division will
be controlled in their movements by an
automatic signal system that will guide
from station to station, from the Mis-
sissippi to the Missouri, a daily stream
of trains expeditiously and without ac-
cident.
The system is one that will replace
the company's operators, in so far as
they have to do with the movement OF
trains between stations, and Is entirely
mechanical. The Hall automatic train
signal service, which the Northwestern
is installing along It's Clinton to Coun-
Gil Bluffs line, Is one Of the most won
derful of the modern Improvements in
railway service. 1t makes possible the
operating of eight trains where one is
operated by the present system. and
with no more risk Of accident.
The preliminary work, which was
begun at Clinton and is moving west
ward, has reached this city, and from
here will be continued toward the Mis-
souri, river. Gangs Of workmen, in the
employ OF the Hall company, have set
poles to carry the wires Of the device
from Clinton to this city. They had
reached point a mile east of the city
Thursday, and were sent west Of the
city to continue the work. w. A. Rob-
inson, formerly lineman for the Iowa
Central, and later OF the Northwest
ern, both here and In Clinton, is in
charge Of the work
Trains Control Signals.
The system, which Is an automatic
one. the power of which as electricity
is one by which the moving trains con-
troll the signals, which tell the engi-
neer that the track ahead is either
clear OF trains or Is occupied. The
signals. which are semaphore arms by
day and lights by night, are very sim
liar to those now In use in the North
Westerns present block system. I'm
like the old, however, they are placed
but a mile apart. while the semaphores
of the present system are In places as
far as ten miles distant one from the
other, depending upon the distance
which separates stations
Each semaphore Of the Hall system
Is controlled by storage battery,
placed in hole in the ground In the
right of-way, which operates the sig
nal. A little device just inside the rail-
furnishes the place OF contact, and
when it's separate parts are pushed to-
gether by the fange of car wheel
passing along the rail, 1t connects the
current, makes a short circuit and gives
the signal. When train passes sig
nal the electric current places the sig
nal at danger, against any train that
might be following, and the position of
the signal tells the engineer Of the
train coming from behind that train
is within the "block" just ahead Of him.
He then must stop until the signal tells
him that the "block' ahead OF him is
cleared.
When the train which closed the
"block" against the one following
reaches the next signal, that one is
thrown against the one following, but
the first one is automatically released
because the current which controlled
1t is broken by the action which set
the second signal.
Run Trains q Mile Apart.
Because the signals, which separate
the BLOCKS" are only mile apart,
1t will be possible to run trains that
distance apart IL the occasion demands.
The signals work as an endless chain.
when one is opened, the one just pre-
viously opened closes, until the next |
one is opened. For that reason trains
can get no nearer together than one
mile. unless the engineer disregards
the signal, or 1t refuses to work, which
tests have not proven. Because the line
is a double tracked system, with all
trains moving in the one direction on
each track, the only necessity to guard
against collisions is from trains APP
from the rear.
The system is also arranged that it
controls tracks that cross from one
line to another, and switch tracks
that branch off from the main line.
It Is said that the system will cost
the Northwestern $4,000 mile. The
road has had the same system in oper-
alton on its line from Clinton to Chi
cago with highly satisfactory results.
The same system is used on the Chi
cago & Alton, and on parts Of the Chi