IEEE Power & Energy Magazine - November/December 2015 - 99

his Postal Telegraph installation and
commercial implementation with alley
L. The GE patents taught the concept,
but Frank Sprague detailed exactly how
to construct every element of his "Traction System" patent.
Convinced that he held the upper
hand, combative GE President Charles a.
Coffin struck first, refusing to fill a tiny
US$365 switch order from Sprague Electric. Sprague responded by cancelling a
US$40,000 order for GE motors needed

in the London elevator installation, giving the business to Westinghouse and
saving US$10,000 in the process. Coffin
then dramatically raised the stakes by announcing that GE would no longer supply any motors and controllers to Sprague
Electric. Gleefully, Frank Sprague replied
that any equipment he did not manufacture himself would henceforth be subcontracted to Westinghouse.
Having won an 1898 contract across
the river from Manhattan in Brooklyn,

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done previously in their extensive research and development organization
and what they could reverse engineer
from the Sprague system. The program was directed by a tough, talented
engineer, E. Wilbur Rice, Jr., who also
held an 1895 patent that read much like
the MU control system, including the
use of pilot motors. as Sprague and
GE started to compete for the same
burgeoning business opportunities, it
quickly became apparent that ownership of the controlling patents would be
a key element to success.
although a detailed analysis of the
patent litigation is beyond the scope of
this article, the related material in the New
York Public Library Frank J. Sprague papers makes for fascinating reading. The
earliest MU patent was "Electrical Railway System," U.S. No. 434,687 (filed 13
august 1889 and issued 1 august 1890)
by prolific independent inventor Charles
J. Van Depoele. although clearly the MU
technology conceptually, Frank Sprague
was able to convince the Patent Office examiner that the control system wouldn't
work. another independent inventor, F.C.
Esmond, received a January 1900 patent, "Unit Multiple System of Control of
Electric Railway," that was also an MU
system. But, for pure volume, in the period from late 1896 until april 1898, GE
led the way with MU-related patents by
W.B. Potter, Frank Case, E. Wilbur Rice,
and others. It is no wonder that GE was
convinced it could win any litigation with
seemingly undermanned Frank Sprague.
But the world's largest electrical company grossly underestimated its opponent
and the masterpiece he and his patent attorney, Thomas Ewing, Jr. (later the U.S.
commissioner of Patents), had created.
U.S. No. 660,065 "Traction System" (filed 30 april 1898 and issued
16 October 1900) by Frank J. Sprague,
with its 59 pages, 73 drawings, and
263 claims, covered every aspect and
detail of the MU system and its controls, which is one reason for the long
gap between filing and issuance as he
successfully argued, defended, and
modified its many elements with the
patent examiner (see Figure 8). He also
enjoyed first reduction to practice with

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Table of Contents for the Digital Edition of IEEE Power & Energy Magazine - November/December 2015