Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1889-07-06
HOME ELECTRICIANS
Have Invented a Novel System Of
Street Car Motive Power and
WILL TEST 1T ON CARSON STREET.
A FEW CHARACTERISTIC FEATURES

ukely be broken DY Booth q FINN on the
line of the West End Street Railway on
Carson street, Southside, for the introduc-
tion and trial OF a new electric railway sys-
tenn. This system is the result of the joint
efforts and inventions of several well-known
Pittsburg gentlemen. Three patents have
already been granted, and three more are
pending in the Patent Office, covering the
system fully. The inventors and patentees
are Messrs. John d. Nicholson, John II.
Dalzell, w. j. MoElroy and 7. J.McTighe,
the two latter being well-known electricians
of this city. These gentlemen were the in
corporators of the National Electric Rail-
way Company, chartered in 1888, and
during the early spring of the present year
deal was made by which their patents
were transferred to the Duquesne
Electric Railway Company of Pennsyl-
vania, for which company an application
for incorporation under the special act of
1887 is now pending. Among the leading
members of the Duquesne Company are W.
j. Hammond, the iron manufacturer, and
Superintendent j. v. Patton, of the Balti-
more and Ohio Railroad Company, and an
arrangement has been made with the West
End Company for thorough trial OF the
system as above stated.
The method to be employed is so radically
different from anything that has yet been
tried, and possesses SO many advantages,
that great interest Is manifested in the mat
ter by street railway companies contemplate
ing an improvement of their service. The
main principles of the new invention were
explained to DISPATCH reporter yesterday
by Mr.. McElroy, the principal inventor.
SOLVING A PROBLEM.
The problem on electric railways is and
has been to establish and maintain an un-
interrupted electrical connection between
the generating .dynamos, located in the
power house, and the moving cars along a
line of road which may extend for two or
three miles on either or both sides of the
station; to insure such economy of power in
the transmission of current as is possible
only with the highest insulation; and above
all, to guard the public against the dangers
of injury to life and property, always Incl
dent to the use of powerful currents of cleo
tricity. Two general methods of transmit
ting the current to the car are in use in this
viz, the overhead or trolley system,
and the conduit, with continuous open slot
similar to the slot of cable road. Both
are Objectionable.
The Duquesne Company's system consists
ofa large copper conductor, insulated in
and protected by an iron pipe laid two feet
below the surface of the street. At inter
walls of 1S or 20 feet along this pipe, are set
heavy cast-iron air-tight boxes containing
an electromagnetic switch, which, as ex-
planned hereafter, controls the supply Of
current from the main conductor to the sur
face plates. Near the box is placed upright |
in the ground q section of heavy. cast-iron
pipe, or post, with q narrow fange at the |
top and very broad fange at the bottom.
This post is three feet long, is embedded in
and is so placed as to bring the |
upper surface of the top fange even with |
the pavement. An insulated iron bolt in |
the center Of the post holds the street con- |
tact plate in position and serves to conduct |
the current to the plate at the proper time. |
The street plates closely resemble an in |
verted saucer; they are six inches in diam |
eter, oval ON top and are the points from /
which the car receives the current; contact |
with the plate being established by long |
bar which swings from the car truck and |
rides over the contact plates with lust |
enough friction to insure good contact, and |
Keep both bar and plates continually bright |
md clean.
The plates are so distanced along the
rack that the contact bar is always in con-
act with one of them; the bar being long
enough to span and cover two plates at the |
anne time, necessarily catches a plate in
ront before it leaves the preceding one.
HOW IT CONNECTS.
If the surface plates were permanently
connected to the main conductor the acme |
# simplicity would be reached, but such
permanent connection would be dangerous.
because of the possibility of shock 70 any-
me coming in contact Herewith.
In the Nicholson Nc Elroy system there
$ absolutely no connection between the
harged main conductor and the exposed
urface plates, only during such times as
he plates are covered and protected by the
ar, and before the car passes off any one
,late that plate must be disconnected from
he main conductor, otherwise the car can
lot proceed The connecting and discon-
lecting OF the street plates with the main
is entirely automatic, and in three
7ears' operation Of the model constructed by
Mr.. McElroy has not once been known to fail.
The mechanism for controlling the connec-
ion is placed, as stated, in the iron boxes.
md is thoroughly protected from dampness
md consequent loss of insulation. The
'oxes are air tight, and being Joined in
cries by the two inch iron pipe which con-
aims the main conductor, form a continuous
pen subway. A slight air pressure is
maintained therein by small air pump in
he power station, and gauge is arranged
0 show any loss OF this pressure caused by
! leak along the line. Notice is thereby
,iven of such defect, and during the time
occupied in locating such leak
ge and repairing the same, no water, the
reat enemy of underground insulation, can
inter- against the escaping volume of air.
The switches in the boxes are actuated by
current of electricity sent into them from
he car, and no currcnt'can be received from
ny given plate until enough current has