Cos Cob Power Station was a historic power station near the
Metro-North Railroad
The Metro-North Commuter Railroad Company , also branded as MTA Metro-North Railroad and commonly called simply Metro-North, is a suburban commuter rail service operated by the Metropolitan Transportation Authority (MTA), a New York State publ ...
tracks, the
Mianus River
The Mianus River is a river in Westchester County, New York, and Fairfield County, Connecticut, in the United States. It begins in the town of North Castle, New York (east of Armonk) in a series of ponds at about altitude. Flowing northeas ...
and Sound Shore Drive in the
Cos Cob area of
Greenwich, Connecticut
Greenwich ( ) is a New England town, town in southwestern Fairfield County, Connecticut, United States. As of the 2020 United States census, 2020 census, it had a population of 63,518. It is the largest town on Gold Coast (Connecticut), Connectic ...
.

The Spanish Revival style station building of 1907 was significant as part of the first mainline railroad electrification in the United States, using
alternating current
Alternating current (AC) is an electric current that periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in w ...
(AC) electrification. The New York City subway systems and a Hudson River railroad line used lower voltage
direct current
Direct current (DC) is one-directional electric current, flow of electric charge. An electrochemical cell is a prime example of DC power. Direct current may flow through a conductor (material), conductor such as a wire, but can also flow throug ...
(DC) electrification, but for longer distances that would mean high transmission losses or frequent and closely spaced substations.
[
A 1903 New York State law prohibited the use of steam locomotives in New York City. The New Haven line of the ]New York, New Haven and Hartford Railroad
The New York, New Haven and Hartford Railroad , commonly known as The Consolidated, or simply as the New Haven, was a railroad that operated principally in the New England region of the United States from 1872 to 1968. Founded by the merger of ...
ran commuter trains into the city, and electrification all the way to New Haven would avoid massive congestion and delays to commuter trains if locomotives were changed at the New York City limits or at Stamford, CT
Stamford () is a city in Fairfield County, Connecticut, United States, outside of New York City. It is the sixth-most populous city in New England. Stamford is also the largest city in the Western Connecticut Planning Region, Connecticut, Weste ...
.
The "New Haven" chose AC electrification as proposed by Baldwin-Westinghouse, with locomotives which could operate on the third-rail DC system within city limits, and the AC system on the main line.
The plant was built by Westinghouse in 1907 in Mission Style, and was located where the Mianus River empties into the Cos Cob Harbor of Long Island Sound. The plant used coal-fired steam turbines, and the three-phase alternators supplied single-phase power at 11 kV 25 Hz directly to the catenary. They also supplied power to the New York Central
The New York Central Railroad was a railroad primarily operating in the Great Lakes and Mid-Atlantic regions of the United States. The railroad primarily connected greater New York and Boston in the east with Chicago and St. Louis in the Midw ...
's Port Morris generating station to compensate the NYC for power consumed by New Haven trains on the NYC's third-rail supplied line to the Grand Central Terminal
Grand Central Terminal (GCT; also referred to as Grand Central Station or simply as Grand Central) is a commuter rail terminal station, terminal located at 42nd Street (Manhattan), 42nd Street and Park Avenue in Midtown Manhattan, New York Ci ...
within the city limits.
The station was designated a Historic Mechanical Engineering Landmark in 1982 by the American Society of Mechanical Engineers
The American Society of Mechanical Engineers (ASME) is an American professional association that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via "continuing edu ...
.
The power station was decommissioned in 1986–87.[ and ]
The plant was listed on the National Register of Historic Places
The National Register of Historic Places (NRHP) is the Federal government of the United States, United States federal government's official United States National Register of Historic Places listings, list of sites, buildings, structures, Hist ...
in 1990,[ but despite the listing and local and national debate, the plant was demolished in 2001. Part of the site is now a public park, and a plaque commemorating the plant is located at the nearby Cos Cob Railroad Station.][
]
See also
* National Register of Historic Places listings in Greenwich, Connecticut
References
Further reading
*
External links
*
**
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{{National Register of Historic Places, state=collapsed
Power stations in Connecticut
Buildings and structures in Greenwich, Connecticut
Former coal-fired power stations in the United States
Long Island Sound
New York, New Haven and Hartford Railroad
Industrial buildings and structures on the National Register of Historic Places in Connecticut
National Register of Historic Places in Fairfield County, Connecticut
Railway buildings and structures on the National Register of Historic Places
Energy infrastructure completed in 1907
Transport infrastructure completed in 1907
Buildings and structures demolished in 2001
Historic American Engineering Record in Connecticut
Demolished buildings and structures in Connecticut
Historic districts on the National Register of Historic Places in Connecticut
Railway buildings and structures on the National Register of Historic Places in Connecticut
Energy infrastructure on the National Register of Historic Places
Former power stations in Connecticut