New Haven RR Cos Cob 1906 Power Plant

(HAER; Satellite, shut down Sept. 22, 1986)

The first single phase power plant in the world supplied 25hz at 11,000 volts for the electrification of the New York, New Haven & Hartford Railroad using Westinghouse equipment. That became the standard for American railroads. Until this electrification, railroads (streetcars, elevated, etc.) generally used direct current. Typically at 600 volts.

HAER CONN,1-GREWI,15A--5

5. VIEW TO THE EAST NORTH EAST FROM PEAK OF THE TURBINE HALL. THE BRICK STACK TO THE RIGHT EXHAUSTED BOILER 904 WHICH WAS INSTALLED IN 1944. STEEL SHEATHED STRUCTURE IN CENTER OF PHOTOGRAPH HOUSED BOILERS 902 AND 903. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

Regular power plants such as ComEd's Fisk generated three phase power at 60hz. And for applications over about 5hp, three phase is preferred. Three phase power requires three wires for transmission.

DeBruler

Single phase requires two wires: supply (high voltage) and return (ground). The rails can be used for the ground wire. So single-phase requires stringing just one wire above the tracks. 

HAER CONN,1-GREWI,15A--10

10. VIEW OF CATENARY AND EAST SIDE OF COS COB POWER PLANT FROM THE EAST NORTH EAST. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

 

Albert R Brecken posted
Cos Cob generating station ( now demolished ) erected by the NHRR in 1906 when railroads ,elevated lines, and street railways had to provide their own power; the very last of such structures to cease operating.

Steven J. Brown posted
NJ Transit GG1 4883 (built 1939 as PRR 4883, scrapped circa 1983) is at South Amboy, New Jersey - September 8, 1982.

 

HAER CONN,1-GREWI,15A--20
20. VIEW OF CATENARY, FEEDER TOWERS AND COS COB POWER PLANT (CENTER BACKGROUND) LOOKING WEST FROM THE NORTH SIDE OF THE MIANUS RIVER BASCULE BRIDGE. NOTE THAT THE CATENARY ENDS AT BRIDGE 313. TRAINS ARE CARRIED ACROSS THE BASCULE BRIDGE BY THEIR OWN MOMENTUM AND PICK UP THE CATENARY ON THE EAST SIDE OF THE RIVER. THE FEEDER LINES CARRY POWER ACROSS THE RIVER ABOVE THE LEVEL OF THE OPENED BASCULE ON THE TOWERS TO THE LEFT AND RIGHT. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

HAER CONN,1-GREWI,15A--24
24. VIEW OF FIRING AISLE OF EAST BOILER ROOM LOOKING SOUTH. BOILERS 900 AND 901 ARE ON THE RIGHT, BOILERS 902, 903, AND 904 ARE ON THE LEFT. NOTE REMAINS OF THE LARRY CAR TRACK SYSTEM FOR TRANSFERRING COAL TO BOILER HOPPERS ABOVE THE AISLE. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

HAER CONN,1-GREWI,15A--40
40. VIEW OF TURBINE HALL LOOKING SOUTHWEST AT WESTINGHOUSE-PARSONS TURBINE NUMBER 2. THIS UNIT WAS INSTALLED IN 1925. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

HAER CONN,1-GREWI,15A--42
42. VIEW OF TURBINE HALL LOOKING WEST NORTHWEST FROM THE MEZZANINE. TURBOGENERATORS 1, 2 AND 3 ARE IN THE FOREGROUND. UNITS IN THE BACKGROUND ARE FREQUENCY CONVERTERS WHICH SUPPLIED 25 CYCLE POER DURING THE TRANSITION FROM COS COB POWER TO UTILITIES POWER. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

There are many more internal photos in the HAER report.

This is the post that taught me about this landmark in electrical development.

Dennis DeBruler

Shut down Sept 22, 1986.

"By 1924 it carried the heaviest passenger traffic of any railroad of its length in the United States, and today brings almost two-million commuters to New York City monthly." [ctmq]

The decision to go with an alternating-current system at 11,000 volts and 25 cycles was based on sound scientific reasons. The determination of the most economical and desirable frequency and voltage of the transmission system involved the consideration of many factors. The choice of frequency was limited to 15 cycles or 25 cycles. The lower frequency afforded a material reduction in weight, size and cost of motors, a reduction in conductor losses and induction disturbances, together with an increase in power factor of the motors. However, adoption of 15 cycles would have materially decreased the commercial value of the system as a whole; other incidental railroad uses would be restricted or prevented. [The footnotes quote three experts that recommend 15 cycles because it simplifies single phase motors for heavy work. That explains why 60hz was not considered.]

New Haven's standard frequency in use for its streetcar operations was 25 cycles, it had power stations generating 25 cycles for trolley operations and its shops were equipped with 25- cycle motors. Adopting 15 cycles would have resulted in the abandonment of a large amount of standard apparatus or installation of expensive frequency converters. [I didn't know any streetcar system used AC. I thought they were all 600v DC with a lot of substations to convert AC to DC.]

Also, New York Central had adopted 25-cycle generators. The management considered a change from 25 to 15 cycles the "equivalent to a break in gauge" and it was decided that "the practical commercial value of the higher frequency outweighed the theoretical merits of the lower one."

Then the engineers considered the voltage to be generated. One proposed system required generators to be designed to the highest practical contemporary limit, 22,000 volts AC. This would maximize transmission range at the expense of constructing voltage-reducing transformer substations along the line. However, the engineers found that system capital cost could be reduced by cutting the system voltage to 11,000 volts AC. This simplified the electrical equipment needed on board the locomotives and eliminated the need for intermediate substations. Operating cost was decreased, and electrical efficiency increased. Current collector design (the pantagraph system) was also simplified. 

[HAER-data, pp30-32]

In the 1980s, the railroad converted to 60hz power from public utilities and upped the voltage to 13,000. [HAER-data, pp97-98]