Idaho labor herald. (Boise, Idaho) 1913-1914, 1914-12-03
The TROLLEY CAR.
How the Electric Current Moves
It Along the Rails.
IT'S MOTORS AND MECHANISM.

An Explanation Of Their Workings and
the Method by Which the Mysterious
Force 10 Conducted From the Over
head Wire to the Running Gear.
or all the thousands and thousands
Of people who daily ride upon the cleo
tRtc street cars of our cities-and q
good many millions more than twelve
billions Of individuals paid a fare on
the trolley lines Of our country last
year-only a few understand what
hauls the cars along the rails
1t IL easy enough to understand the
steam railroad system A steam en-
gine. mounted on wheels. is hitched to
number of cars. The steam engine
part Of the locomotive Is coupled to the
driving wheels, and when the engine is
started the wheels turn and the train
moves.
But the electric street car Is quite
another thing and vastly harder to un-
derstand. In vague way the vast ma
jority of people who ride know that it
is driven by electric power which is
carried In some mysterious manner on
the trolley wires.
Let us take car apart, nguratively
speaking. and see just how it is made
Beneath the ordinary street car you
will find two to four powerful electric
motors geared directly to the axles Of
the car trucks.
These motors differ somewhat from
ordinary electric motors in their de-
sign. but they operate exactly the same
rs the electric motor which drives an
'f1ce fan. the sewing machine or the
Tacuum cleaner In the home These
motors are very powerful and are al
most completely hidden from sight In
the trucks beneath the car.
The electrical energy for driving the
street cars is sent out over the trolley
wires. The electrical power is general.
ed, or made. In the central power
house. or 1t may be transmitted from
some nearby water power development
where the energy of the falling water
Is changed into electricity. The troll
ley wire is suspended above the street
from poles and say wires.
The electricity is kept on the trolley
wires by suitable insulators of glass,
porcelain or composition. over which
the current cannot travel The elec
trical current flows easily and smooth
~ along the trolley wire. like water in
pipe. although it cannot be seen
Wherever the copper wire extends
lhe electrical power flows and Is al.
ways ready to drive a trolley car.
Each trolley car Is provided with a
fFnIlnu uyhnal NJ h.
which runs along the under sNde of the
trolley wire The electrical power
from the trolley wire flows through
this wheel and down the trolley pole
to heavily insulated cable concealed
In the top of the car This cable carries
the electricity to the controller In
front OF the car.
The controller is the iron box which
stands in front of the motOrman. At
the top OF this box are two levers.
The smaller lever ia used to turn on
and of the current supply and the
larger is used to control the curreDt,
or to feed" 1t to the motors benea,n
the car in any quantity as desired.
When the mOtOrman turns the con.
Uoller handle few notches a certain
amount OF electricity Is allowed to
now from the overhead trolley wire
down the pole. through the cable and
control box to the motors beneath the
car The current starts the motors,
which in turn cause the wheels OF the
car to revolve. the car starts and the
motorman turns the controller handle
further. feeding the motors more cur
rent. and the car picks up to it's regu.
lar running speed.
The electrical current flows to the
car over the trolley wire After 1t
nows through the car. via the cables.
through the controller. the resistance
and the motors. It flows out of hhe car
through the iron wheels and back to
the power house along the steel rails,
thus completing the circuit Electrical
News.