IEEE Power & Energy Magazine - September/October 2015 - 72

history

Thomas J. Blalock

an unusual frequency
40-Hz power in the early years

IN THE 1890s, 60-Hz HAD NOT
yet become the definitive standard
frequency to be used for the supply of
alternating current (ac) power in the
United States. It was in use, but two
other frequencies became significant
as well. As a result of the huge success
of the first 25-Hz power house at Niagara Falls, New York, in 1895, this frequency became a standard for use with
large, slow-speed rotating machines.
The resulting dual-frequency standard of 25/60-Hz was considered by
many to be unfortunate. Consequently,
the General Electric Company (GE) attempted to introduce a single frequency,
40 Hz, hoping that it would eventually replace both of these established frequencies. This concept came too late, however, and just served to further complicate
the situation with a third frequency.

Background
Following his pioneering work with the
incandescent lamp at Menlo Park, New
Jersey, Thomas Edison established the
Edison Machine Works on Goerck
Street (now gone) in lower Manhattan,
New York City, for the manufacture
of dynamos and related direct current
(dc) equipment. This factory produced
the Edison "Jumbo" dynamos used in
the landmark Pearl Street generating
station nearby in 1882.
The great success of the Pearl Street
station, however, led to such an increased demand for dynamos (dc generators) that the Goerck Street factory
Digital Object Identifier 10.1109/MPE.2015.2435597
Date of publication: 18 August 2015

ieee power & energy magazine

The early development of alternating current (ac) power systems was marked
by the use of a number of different frequencies, which generally ranged from
16 2/3 Hz to as high as 133 Hz. It was found that higher frequencies were better for electric lighting while lower frequencies had advantages for operating
electrical equipment such as motors, generators, and rotary converters. Over
the years, much effort went into developing a single compromise frequency that
would be suitable for most electrical applications. Eventually, 60-Hz power came
to predominate in North America, in part of South America, and in a handful of
other counties. Similarly, a standard of 50 Hz was adopted in Europe, Africa, Asia,
Australia, and in the remainder of South America. Prof. Dr. Gerhard Neidhöfer
authored a comprehensive article on the development of the 50- and 60-Hz frequency standards that appeared in the July/August 2011 issue of this magazine.
This issue's "History" article, written by Thomas J. Blalock, a frequent contributor to IEEE Power & Energy Magazine, details the promotion, chiefly by the
General Electric Company, of a 40-Hz frequency standard that enjoyed some
initial success but ultimately failed to displace 60 Hz as the standard frequency.
Tom Blalock earned a B.S.E.E. degree from Lafayette College and an M.E.E.E.
degree from Rensselaer Polytechnic Institute. His duties as a development engineer at the former General Electric High-Voltage Engineering Laboratory and
later as a test engineer in the Transformer Test Department, both in Pittsfield,
Massachusetts, included a broad range of duties, including lightning protection
and high-voltage switching surge studies. Since retiring from General Electric,
Tom has actively pursued his hobby of "industrial archaeology," with particular emphasis on the exploration, preservation, and careful documentation of
historically important and interesting electric power projects and equipment.
We welcome Tom back as our guest history author for this issue of IEEE

Power & Energy Magazine.
-Carl Sulzberger
Associate Editor, History

quickly became hopelessly overcrowded. Therefore, Edison sent out "scouts"
to search in the surrounding countryside for a new location for this opera1540-7977/15©2015IEEE

tion. One such scout came upon two
nearly completed industrial buildings
on the outskirts of the city of Schenectady in upstate New York. Walter
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