accomplishments and life of F.J. Sprague. 1857-1934
Hailed during his lifetime
as the "Father of Electric Traction" by leaders in the
fields of science, engineering and industry, Frank Julian Sprague's
achievements in horizontal transportation were paralleled by equally
remarkable achievements in vertical transportation. During a six-decade
career, Sprague distinguished himself as an inventor for his accomplishments
in the development of the electric railway, early electric elevators
and the commercial electric motor.
Frank Julian Sprague (1857-1934)
Sprague was born in Milford,
Connecticut in 1857. He attended Drury High School and excelled in mathematics.
Sprague won the appointment to the U.S. Naval Academy, and with US $400
in borrowed cash, set out for Annapolis, Maryland, in 1874.
Graduating seventh in a class
of 36 in 1878, Sprague was assigned to the USS Richmond, flagship of
the Asiatic Fleet, where he filled a notebook with detailed drawings
and descriptions of devices that evidenced his urge for invention. Among
these were a duplex telephone, quadruplex and octoplex telegraph systems,
a motor and a means of transmitting pictures by wire. Later, Sprague
was ordered to the USS Minnesota. While his ship was in Newport, Rhode
Island, in 1881, Sprague invented the inverted type of dynamo. Also
in 1881, Spraque transferred to the USS Lancaster, flagship of the European
Squadron, on which he installed the first crude electrical call-bell
system in the Navy.
Sprague took leave to attend
the Paris Electrical Exhibition and the Crystal Palace Exhibition in
Sydenham, England, where he served as the only American member and as
secretary of the jury of awards for gas engines, dynamos and lamps.
Meanwhile, Sprague's ideas
about motors and lamps had so impressed E.H. Johnson, a business associate
of Thomas A. Edison, that he convinced Sprague to resign from the Navy
in 1883 to become a technical assistant to Edison. While on Edison's
staff, Sprague assisted in the installation and operation of Edison's
pioneer three-wire electric light systems. Sprague also revised and
corrected the Edison system of mains and feeders for central station
distribution and developed a formula for determining the ratio of wire
size to current amperage.
However, Edison's primary
interest was in light, while Sprague was interested in power. He resigned
his position after about a year and started the Sprague Electric Railway
& Motor Company in 1884. During the next two years, Sprague produced
a number of inventions of major significance.
The first was a constant-speed,
nonsparking motor with fixed brushes. The first motor to maintain constant
revolutions per minute under different loads. Sprague's invention caused
such a stir at its first showing at the Franklin Institute's Electrical
Exhibition in Philadelphia that the company sold 250 motors in two years.
In 1885, the Edison Electric
Light Company officially endorsed Sprague's motor in a circular sent
to its local companies. "A practical motor has been a want seriously
felt in our system," it read. "The Sprague motor is believed
to meet . . . all the exigencies of the case, and the Edison Electric
Light Company feels it can safely recommend it to all its licensees
as the only practical and economic motor existing today."
Next, Sprague designed a
method to regenerate -- or return -- power to the main supply systems
of electric-motor-driven equipment, such as elevators and trains for
economy and braking. This was later used extensively on mountain grades
in electrical train operation and for interchange of energy in elevator
groups. Additionally, Sprague developed a distorted system of compound
field magnet winding that maintained a fixed nonsparking position of
commutator brushes and a three-point, wheelbarrow suspension of axle-mounted
geared motors for electric railways, which was soon used universally
for trolley-car equipment.
railway motor from the 1880s
Sprague incorporated many
of these inventions in the equipment his company installed for the Richmond
(VA) Union Passenger Railway in 1887-1888, the first large-scale electric
trolley line in the world. Within two years of its opening, 110 electric
railroads using Sprague's equipment were built or under contract, including
systems in Italy and Germany.
In 1890, Edison General Electric
Company, which manufactured much of Sprague's equipment, purchased and
absorbed the Sprague Electric Railway & Motor Company, and Sprague
turned his attention to the field of vertical transportation.
Thomson and Frank Sprague in their later years working for General
to the Engineering Hall of Fame
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