ASME-Landmark:AC Electrification of the New York, New Haven, & Hartford Railroad


In 1903, a New York State law prohibited the use of steam locomotives in New York City. At the time, the New York, New Haven, and Hartford Railroad ran commuter trains into the city; recognizing that changing locomotives at the city limits would cause massive congestion and delays, the railroad chose to operate entirely under electric power.

At the time, the New York City subway systems and a Hudson River railroad line used lower voltage direct current (DC) electrification, but DC current over longer distances would mean high transmission losses or frequent and closely spaced substations. Thus, the railroad chose alternate current (AC) electrification, with locomotives that could operate on the third-rail DC system within city limits and the AC system on the main line.

On July 24, 1907, the first regular train to be operated under electric power completed a trip from Grand Central to New Rochelle, New York. Electrification was extended to Stamford in October of 1907.

The major components of the system were developed by the engineering staffs of the New York, New Haven, & Hartford Railroad and the Westinghouse Electric and Manufacturing Company of East Pittsburgh, Pennsylvania.

This was a pioneering venture in mainline railroad electrification and was a proving ground for railroad electrification technology, establishing single-phase alternating current as a technical and economical alternative to direct current. This concept exerted considerable influence over subsequent systems both in the United States and abroad.

The Cos Cob plant, which switched from coal to oil and gas in the late seventies, operated until October 1986. The plant was demolished in 2001. See ASME website for more information