Custer weekly chronicle. [volume] (Custer City, S.D.) 1890-1931, 1891-12-12
The New Edison Electric Railway Sys-
IA

A description of the new electric rail-
way system invented by Mr.. Edison, Of
which there has been brief mention In
the daily papers recently, is given in
the current issue of the Electrical En-
gineer, which we reprint. II says:
Mr. Edison has settled upon a system
i'm which current is conveyed from the
central station at high potential to motor
generators placed below the ground in
close proximity to the rails, and which
convert the current transmitted at the
pressure of, say 900 volts to one Of 20
volts between rail and rail, with O cor
responding increase in the volume of
the current. With the utilization of
heavy currents at low voltage it became
necessary TO devise apparatus to pick up
with absolute certainty 1000 amperes Of
current through two inches of mud if
necessary; and this Mr.. Edison has
done. 1t was next .socessary To obtain
a joint between contiguous rails that
would permit of the passage Of several
thousand amperes without introducing
undue resistance. This has also been
accomplished, with the result that an
experimental track Of abont quarter of
mile in length has been in actual
operation near Mr.. Edison's laboratory
for some time past, and working to his
complete satisfaction
1t has been said that carriages with
iron wheels passing over the tracks
would short-circut the current and
cause destruction of the dynamo ma
chimes, as well as "chew.up" the short
circuiting vehicle. TO test this Mr.. Edi-
son actually shor..circuited his expert
mental track with carriage having
iron wheels, and succeeded in getting
only 200 amperes through the wheels,
the low voltage used AZ we'll as the in
sulating properties of the axle grease,
being sufficient TO account for the small
quantity of current which actually pass
ed through.
Regarding the leakage Of current be-
tween rail and rail, Mr.. Edison's expert
meDts have proved that at potential
difference Of 20 volts the loss under the
worst conditions, with wet and salted
track, is only I'll. j. per mile, while
very wet weather would involve q loss
Of only % III. i. And as regards the
question of safety TO human beings and
animals likely to come in contact with
the rail. ii is needless to say that the
effect of 20 volts upon the human body
is imperceptible, and actual experiment
has also shown that horses are not af.
fected by it in the slightest degree.
While not differing in principle from
the ordinary type of street railway
motor, the motor on this system would
be practically waterproof without nee
esstating any special protective cover
ing for that purpose.
The cost of this system Mr. Edison
estimates, will vary betw cen $4,000 and
100000 per mile Of double track, not in
cluding the cost of the stations, and de-
pending between these limits upon the
amount Of traffic. The running expens-
es, he estimates, will he exactly the
same as those on the overhead trolley
wire system. Where the traffic permits
Of it the system can be applied with
greater economy than cable road. In
conclusion we may add that estimates
are now being prepared for the con-
version ot one of the largest street rail-
ways in New York City over to the
electric system, after the plan of MIR.
Edison, aud it is to be hoped that ar.
rangements will soon be effected by
which the system may receive q practi-
cal trial on large scale in the near
future.