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AS narrated in Chapter XVIII, there were
two electric railroads installed by Edison at
Menlo Park--one in 1880, originally a
third of a mile long, but subsequently increased
to about a mile in length, and the other in
1882, about three miles long. As the
1880 road was built very soon after
Edison's notable improvements in dynamo
machines, and as the art of operating them to
the best advantage was then being developed,
this early road was somewhat crude as compared
with the railroad of 1882; but both were
practicable and serviceable for the purpose of
hauling passengers and freight. The scope of
the present article will be confined to a
description of the technical details of these two
installations.
The illustration opposite page 454 of the
preceding narrative shows the first Edison
locomotive and train of 1880 at Menlo
Park.
For the locomotive a four-wheel iron truck was
used, and upon it was mounted one of the long
"Z" type 110-volt Edison dynamos, with a
capacity of 75 amperes, which was to be used
as a motor. This machine was laid on its side,
its armature being horizontal and located toward
the front of the locomotive.
We now quote from an article by Mr. E. W.
Hammer, published in the Electrical World,
New York, June 10, 1899, and
afterward elaborated and reprinted in a volume
entitled Edisonia, compiled and published under
the auspices of a committee of the Association
of Edison Illuminating Companies, in
1904: "The gearing originally employed
consisted of a friction-pulley upon the armature
shaft, another friction- pulley upon the driven
axle, and a third friction-pulley which could
be brought in contact with the other two by a
suitable lever. Each wheel of the locomotive
was made with metallic rim and a centre portion
made of wood or papier- mache. A three-legged
spider connected the metal rim of each front
wheel to a brass hub, upon which rested a
collecting brush. The other wheels were
subsequently so equipped. It was the
intention, therefore, that the current should
enter the locomotive wheels at one side, and
after passing through the metal spiders,
collecting brushes and motor, would pass out
through the corresponding brushes, spiders, and
wheels to the other rail."
As to the road: "The rails were light and
were spiked to ordinary sleepers, with a gauge
of about three and one-half feet. The sleepers
were laid upon the natural grade, and there was
comparatively no effort made to ballast the
road. . . . No special precautions were
taken to insulate the rails from the earth or
from each other."
The road started about fifty feet away from the
generating station, which in this case was the
machine shop. Two of the "Z" type dynamos
were used for generating the current, which was
conveyed to the two rails of the road by
underground conductors.
On Thursday, May 13, 1880, at 4
o'clock in the afternoon, this historic
locomotive made its first trip, packed with as
many of the "boys" as could possibly find a
place to hang on. "Everything worked to a
charm, until, in starting up at one end of the
road, the friction gearing was brought into
action too suddenly and it was wrecked. This
accident demonstrated that some other method of
connecting the armature with the driven axle
should be arranged.
"As thus originally operated, the motor had
its field circuit in permanent connection as a
shunt across the rails, and this field circuit
was protected by a safety-catch made by turning
up two bare ends of the wire in its circuit and
winding a piece of fine copper wire across from
one bare end to the other. The armature circuit
had a switch in it which permitted the locomotive
to be reversed by reversing the direction of
current flow through the armature.
"After some consideration of the gearing
question, it was decided to employ belts instead
of the friction-pulleys." Accordingly,
Edison installed on the locomotive a system of
belting, including an idler-pulley which was
used by means of a lever to tighten the main
driving-belt, and thus power was applied to the
driven axle. This involved some slipping and
consequent burning of belts; also, if the belt
were prematurely tightened, the burning-out of
the armature. This latter event happened a
number of times, "and proved to be such a
serious annoyance that resistance-boxes were
brought out from the laboratory and placed upon
the locomotive in series with the armature.
This solved the difficulty. The locomotive
would be started with these resistance-boxes in
circuit, and after reaching full speed the
operator could plug the various boxes out of
circuit, and in that way increase the speed."
To stop, the armature circuit was opened by the
main switch and the brake applied.
This arrangement was generally satisfactory,
but the resistance-boxes scattered about the
platform and foot-rests being in the way,
Edison directed that some No. 8 B. & S.
copper wire be wound on the lower leg of the
motor field- magnet. "By doing this the
resistance was put where it would take up the
least room, and where it would serve as an
additional field-coil when starting the motor,
and it replaced all the resistance-boxes which
had heretofore been in plain sight. The boxes
under the seat were still retained in service.
The coil of coarse wire was in series with the
armature, just as the resistance-boxes had
been, and could be plugged in or out of circuit
at the will of the locomotive driver. The
general arrangement thus secured was operated as
long as this road was in commission."
On this short stretch of road there were many
sharp curves and steep grades, and in
consequence of the high speed attained (as high
as forty-two miles an hour) several derailments
took place, but fortunately without serious
results. Three cars were in service during the
entire time of operating this 1880 railroad:
one a flat-car for freight; one an open car
with two benches placed back to back; and the
third a box-car, familiarly known as the
"Pullman." This latter car had an
interesting adjunct in an electric braking system
(covered by Edison's Patent No.
248,430). "Each car axle had a large
iron disk mounted on and revolving with it
between the poles of a powerful horseshoe
electromagnet. The pole- pieces of the magnet
were movable, and would be attracted to the
revolving disk when the magnet was energized,
grasping the same and acting to retard the
revolution of the car axle."
Interesting articles on Edison's first
electric railroad were published in the technical
and other papers, among which may be mentioned
the New York Herald, May 15 and July
23, 1880; the New York Graphic, July
27, 1880; and the Scientific American,
June 6, 1880.
Edison's second electric railroad of 1882
was more pretentious as regards length,
construction, and equipment. It was about
three miles long, of nearly standard gauge, and
substantially constructed. Curves were
modified, and grades eliminated where possible
by the erection of numerous trestles. This road
also had some features of conventional
railroads, such as sidings, turn-tables,
freight platform, and car-house. "Current
was supplied to the road by underground feeder
cables from the dynamo-room of the laboratory.
The rails were insulated from the ties by giving
them two coats of japan, baking them in the
oven, and then placing them on pads of
tar-impregnated muslin laid on the ties. The
ends of the rails were not japanned, but were
electroplated, to give good contact surfaces for
fish-plates and copper bonds."
The following notes of Mr. Frederick A.
Scheffler, who designed the passenger
locomotive for the 1882 road, throw an
interesting light on its technical details:
"In May, 1881, I was engaged by Mr.
M. F. Moore, who was the first General
Manager of the Edison Company for Isolated
Lighting, as a draftsman to undertake the work
of designing and building Edison's electric
locomotive No. 2.
"Previous to that time I had been employed in
the engineering department of Grant Locomotive
Works, Paterson, New Jersey, and the
Rhode Island Locomotive Works, Providence,
Rhode Island....
"It was Mr. Edison's idea, as I
understood it at that time, to build a
locomotive along the general lines of steam
locomotives (at least, in outward
appearance), and to combine in that respect the
framework, truck, and other parts known to be
satisfactory in steam locomotives at the same
time.
"This naturally required the services of a
draftsman accustomed to steam-locomotive
practice.... Mr. Moore was a man of great
railroad and locomotive experience, and his
knowledge in that direction was of great
assistance in the designing and building of this
locomotive.
"At that time I had no knowledge of
electricity.... One could count so-called
electrical engineers on his fingers then, and
have some fingers left over.
"Consequently, the ELECTRICAL
equipment was designed by Mr. Edison and his
assistants. The data and parts, such as
motor, rheostat, switches, etc., were given
to me, and my work was to design the supporting
frame, axles, countershafts, driving
mechanism, speed control, wheels and boxes,
cab, running board, pilot (or
`cow-catcher'), buffers, and even supports
for the headlight. I believe I also designed a
bell and supports. From this it will be seen
that the locomotive had all the essential
paraphernalia to make it LOOK like a steam
locomotive.
"The principal part of the outfit was the
electric motor. At that time motors were
curiosities. There were no electric motors even
for stationary purposes, except freaks built for
experimental uses. This motor was made from the
parts-- such as fields, armature,
commutator, shaft and bearings, etc., of an
Edison "Z," or 60-light dynamo. It was
the only size of dynamo that the Edison Company
had marketed at that time.... As a motor,
it was wound to run at maximum speed to develop a
torque equal to about fifteen horse-power with
220 volts. At the generating station at
Menlo Park four Z dynamos of 110 volts were
used, connected two in series, in multiple
arc, giving a line voltage of 220.
"The motor was located in the front part of the
locomotive, on its side, with the armature
shaft across the frames, or parallel with the
driving axles.
"On account of the high speed of the armature
shaft it was not possible to connect with
driving-axles direct, but this was an advantage
in one way, as by introducing an intermediate
counter-shaft (corresponding to the well-known
type of double-reduction motor used on
trolley-cars since 1885), a fairly good
arrangement was obtained to regulate the speed of
the locomotive, exclusive of resistance in the
electric circuit.
"Endless leather belting was used to transmit
the power from the motor to the counter-shaft,
and from the latter to the driving-wheels,
which were the front pair. A vertical
idler-pulley was mounted in a frame over the
belt from motor to counter-shaft, terminating
in a vertical screw and hand-wheel for
tightening the belt to increase speed, or the
reverse to lower speed. This hand-wheel was
located in the cab, where it was easily
accessible....
"The rough outline sketched below shows the
location of motor in relation to counter-shaft,
belting, driving-wheels, idler, etc.:
"On account of both rails being used for
circuits, . . . the driving-wheels had to be
split circumferentially and completely insulated
from the axles. This was accomplished by means
of heavy wood blocks well shellacked or otherwise
treated to make them water and weather proof,
placed radially on the inside of the wheels, and
then substantially bolted to the hubs and rims of
the latter.
"The weight of the locomotive was distributed
over the driving-wheels in the usual locomotive
practice by means of springs and equalizers.
"The current was taken from the rims of the
driving-wheels by a three-pronged collector of
brass, against which flexible copper brushes
were pressed--a simple manner of overcoming any
inequalities of the road-bed.
"The late Mr. Charles T. Hughes was in
charge of the track construction at Menlo
Park.... His work was excellent
throughout, and the results were highly
satisfactory so far as they could possibly be
with the arrangement originally planned by Mr.
Edison and his assistants.
"Mr. Charles L. Clarke, one of the
earliest electrical engineers employed by Mr.
Edison, made a number of tests on this 1882
railroad. I believe that the engine driving the
four Z generators at the power-house indicated
as high as seventy horse-power at the time the
locomotive was actually in service."
The electrical features of the 1882
locomotive were very similar to those of the
earlier one, already described. Shunt and
series field-windings were added to the motor,
and the series windings could be plugged in and
out of circuit as desired. The series winding
was supplemented by resistance- boxes, also
capable of being plugged in or out of circuit.
These various electrical features are
diagrammatically shown in Fig. 2, which also
illustrates the connection with the generating
plant.
We quote again from Mr. Hammer, who says:
"The freight- locomotive had single reduction
gears, as is the modern practice, but the power
was applied through a friction-clutch The
passenger-locomotive was very speedy, and
ninety passengers have been carried at a time by
it; the freight- locomotive was not so fast,
but could pull heavy trains at a good speed.
Many thousand people were carried on this road
during 1882." The general appearance of
Edison's electric locomotive of 1882 is
shown in the illustration opposite page 462 of
the preceding narrative. In the picture Mr.
Edison may be seen in the cab, and Mr.
Insull on the front platform of the
passenger-car.
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