The Simonds Mfg. Company of Fitchburg, Mass., were among the
first of the manufacturers in New England to realize the immense
advantages to be derived from the electrical distribution of
power, particularly where water power, otherwise unavailable,
could be utilized to furnish the initial energy.
Wanoosnoc Brook, which has a flow of about 2000 cubic feet per
minute, and which has a rapid descent through a gorge some 3
miles from the city of Fitchburg, furnished to the Simonds
Company a ready means of substituting water power for that of
steam in their works.
At a narrow point in the gorge above mentioned a stone dam was
constructed about 30 feet high, and which impounds approximately
800,000 cubic feet of water. From the dam water is conveyed to
the power house, a distance of about 1800 feet, through an
8-foot steel pipe, the upper half of this pipe being No. 8 gauge
and the lower No. 6 gauge steel.
This is thicker than the actual pressure demands, but the
company have installed every detail in connection with this
plant in such a manner that when they improve their water rights
on the Wanoosnoc Brook above their present dam the plant could
be enlarged to accommodate an additional head, and all the power
resulting there from utilized wit out any unnecessary delay in
making the change.
The pipe is carried above the ground on stone piers, 16 feet
apart; it terminates in a 4 foot main 20 feet long, this
enlargement being for the purpose of avoiding loss of head
through friction. Three 20-inch pipes convey water from the main
to within about 2 feet from the wheels, where each pipe is
further subdivided so that the water is discharged through two
nozzles on each wheel.
From the top of the dam to these nozzles there is 131 feet fall,
giving a spouting velocity of 5480 feet per minute at the
nozzles. There are six wheels, which were supplied by the Pelton
Water Wheel Company. They are 28 inches in diameter, all mounted
on the same shaft, the wheels being enclosed in three water
tight cases (two wheels in each case) as shown in the engraving.
Each wheel is fitted with a double nozzle.
By this means two streams are discharged upon the lower part of
the wheels. Under the present head each of these wheels has a
capacity of 70 horse-powers, or 420 horse-power for the six.
Should the company decide to enlarge their plant those same
wheels could, by substituting new buckets, and without any other
change, have their capacity increased to something over 600
The speed regulation is effected by means of an automatic
differential governor, which acts upon the valves in the rear of
the nozzle chambers. The constant speed end of this governor is
operated by a 20 horse-power Pelton water wheel, which also
drives the exciter.
The electrical apparatus, which was manufactured and installed
by the Westinghouse Electric & Mfg. Company, is of the latest
and most approved type. The generator is an alternating current
300 kilowatt, two-phase machine, furnishing current at an
electro motive force of 2250 volts, and runs at 375 revolutions
per minute, being directly connected to the water wheel shaft,
from which, however, it is separated by an insulating coupling.
Should it be decided to make the enlargement above referred to,
a similar generator of 150 kilowatts capacity would be directly
coupled to the other end of the water wheel shaft.
The generator is of the “Plus two” type, the peculiarity of this
type being that the armature has two more teeth than the field
has poles. In this case there are 20 teeth on the armature and
18 poles in the field. The armature is of the standard toothed
armature variety and is provided with highly insulated machine
The field current is supplied from an 11.25 kilowatt multipolar
exciter, which is driven by a belt from the Pelton water motor,
which also drives the constant speed and of the water wheel
governor. Current from this exciter also serves to supply the
incandescent lights which are distributed about the generating
From the generator the current passes to the switchboard, which
is incombustible, having an angle iron frame and white marble
panels, on which the instruments are mounted. The latter
consists of an alternating current rheostat for the field of the
generator, direct current rheostat for the exciter, main line
switches, field switches, ammeters, voltmeters, voltmeter
converters, fuses and ground detectors, and back of the board
are mounted two Shallenberger differential Watt meters for
measuring the actual output of the station. This board, being
constructed entirely of marble and brass, presents a very
From the switchboard the conductors are carried to the lightning
arrester devices - of the Wurts non-arcing metal type and thence
to the transmission circuits. These consist of four stranded
conductors, each having a cross section equal to that of a No.
000 B. & S. wire, and are covered with weather proof insulation.
The line is 2.15 miles long and was installed with the greatest
care, in order that all risks from accident should be reduced to
a minimum. The reducing transformer station, which is located at
the works of the company, consists of two Westinghouse standard
light and power transformers of 100 kilowatts capacity each.
These transformers are oil insulated and are cooled by means of
a coil of pipe, through which a small amount of water flows,
thus effectually doing away with all danger from overheating.
These transformers reduce the electromotive force of 2250 volts
to 220 volts secondary, at which the current is distributed to
the various motors placed in the different departments of the
works. The motors are of the standard Westinghouse two-phase
Tesla self-starting type, and are distributed as follows.
One 75 horse-power motor is located in the band saw department,
doing all the work required there, including the grinding,
polishing, &c., two 50’s and one 30 take care of the circular
saw grinding and polishing; one 30 runs the machine room and
wood working department. The 20, 15 and 10 and 7-1/2 motors run
smaller departments of special lines, and it has been divided up
in this way in order to run different departments of the factory
at any time without running the whole works, which has been
found of considerable advantage in comparison with engines
connected together running the whole plant.
In addition to these motors the company has placed an order with
the Westinghouse Company for a 225 horse power two-phase Tesla
self-starting motor, which is to be operated directly from the
high potential transmission circuits without the use of step
down transformers. This motor will be used to run the grinding
room, in which there are some 18 grindstones for grinding cross
cut saws, knives, &c., and to judge something of the power
required to do this work there are several machines which, when
the work is passing through any process of grinding, take 88
horse-power for each machine.
Since the introduction of motors in place of steam power it has
been found that more work is accomplished, and power is very
much more uniform than could possibly be had with steam, as it
is kept right up to its full speed all the time. The entire
plant now in use has been running some time with the greatest
success and economy and is giving the best of satisfaction.
The Iron Age, Vol.55, June
(New York: David Williams, Publisher and Proprietor).