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A Mammoth Move

Relocating the 50th Street Substation

The “History” article in the January/February 2013 issue of IEEE Power & Energy Magazine covered the design, construction, and railway electrification of the iconic Grand Central Terminal, which officially opened in early 1913. By 1929, it became necessary for the New York Central Railroad to remove the boiler house and substation associated with the terminal and located at 50th Street in Manhattan, New York. This history article, written by Thomas J. Blalock, a frequent contributor to this magazine, covers the herculean effort that took place in 1929 and 1930 to dismantle the facilities at 50th Street, move the usable equipment south a distance of seven city blocks or about 1/3 mi (0.53 km), and build the new substation as much as 100 ft (30.5 m) below street level in a cavernous excavation hewn out of the bedrock of Manhattan Island. The new substation was reportedly the largest substation in the world at that time.

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 Blalock back as our guest history author for this issue of IEEE Power & Energy Magazine.

—Carl Sulzberger
Associate Editor, History

figure 1. The main waiting room of Grand Central Terminal, now an exhibition space called Vanderbilt Hall (photo courtesy of the Museum of Innovation and Science (miSci) Archives, Schenectady, New York).

figure 1. The main waiting room of Grand Central Terminal, now an exhibition space called Vanderbilt Hall (photo courtesy of the Museum of Innovation and Science (miSci) Archives, Schenectady, New York).

The present Grand Central Terminal on 42nd Street in midtown Manhattan, New York City, opened in 1913. A recent article in this column described in detail the electrification of the terminal to eliminate the need for steam locomotives in its operation (see Figure 1).

This project included the construction of a steam plant and a power substation at 50th Street, several blocks north of the new terminal. In 1929, the imminent construction of a new Waldorf-Astoria Hotel at that location required the removal of this facility. The need for a steam plant was eliminated by the decision to purchase the steam from a commercial steam supplier instead. The substation, however, was still necessary since its rotary converters supplied the direct current (dc) for the third rails, which powered the trains in and north of Grand Central Terminal. Consequently, it was decided to move the entire substation to a location within Grand Central itself.

Early Grand Central Power

In 1871, Grand Central Depot was built at the same location as the present Grand Central Terminal. That facility was designed for steam locomotive use exclusively, but electric power was provided for lighting purposes.

Some details regarding the very early use of electric power at Grand Central are contained in an unpublished write-up by the New York Central Railroad (actual author unknown), a copy of which I obtained in 1989 from Robert Walker, the former chief power engineer (now retired) for the New York Metropolitan Transportation Authority (MTA) Metro-North Railroad.

The first electric plant for lighting the depot was constructed in the surface train yards located north of the depot itself, at 46th Street and Madison Avenue. No details of this plant are known, but it would have had to supply arc lighting for the yards since this installation predated the development of the first practical incandescent lamp by Thomas Edison in 1879. By 1882, however, this plant had been expanded to include a 150-hp “Ideal” steam engine belted to two 45-kW Edison bipolar generators that provided dc for 900 incandescent lamps, using a three-wire (110/220-V) distribution system.

In addition, the plant supplied 107 arc lamps within the depot itself. Also, a “breakdown” service from the Edison Electric Illuminating Company had been installed to replace gas light chandeliers that, previously, had been used as emergency lighting sources. Lighting in the depot offices, however, was supplied directly from the Edison Company normally.

In 1888, an annex was built on the east side of the depot to provide more tracks at platforms to accommodate increased rail passenger traffic. Additional electric power for lighting was supplied by a 50-hp steam engine belted to a 25-kW generator in a facility located at 42nd Street and Depew Place (a short north-south street named for Chauncey Depew, president of the New York Central Railroad at the time).

During the late 1890s, a massive reconstruction of the depot was undertaken to provide even more extensive facilities for the still rapidly increasing passenger traffic. The exterior of this new building was completed in 1898, but the interior renovations were not completed until 1900. Due to the magnitude of these alterations, it was decided to rename the facility Grand Central Station (replacing “Depot” in the name).

An extensive new electric generating plant was incorporated into the new facility. This was located beneath the west side of the station, at 43rd Street, and it extended into a vault beneath the sidewalk along Vanderbilt Avenue, a north-south street running along the west side of the station (named for Cornelius “Commodore” Vanderbilt, the instigator and patron saint of the New York Central Railroad empire and its Grand Central complex).

The basement-level boiler room for this plant had only 9 ft (2.74 m) of headroom. Thus, an unusual type of boiler installation was utilized. This consisted of six 200-hp “Belpaire” locomotive-type boilers that required comparatively little headroom for their installation and operation. The boiler room was 300 ft (91.4 m) in length, and the boilers all fed into a 10-in (25.4-cm) diameter steam main.

This main provided steam for the operation of four Ball and Wood high-speed, horizontal steam engines. The engines drove four Crocker-Wheeler dc generators with a total capacity of 425 kW. At some later date, a fifth Ball and Wood engine was added to drive a 150-kW General Electric dc generator, which increased the total plant capacity to 575 kw. This amounted to a total of 5,230 A supplied at the standard 110 V, and all distribution was by means of simple two-wire circuits. There was no motor load of any consequence, and the combined arc and incandescent lighting load was said to be equivalent to 6,000 incandescent lamps of that period.

As was often the practice in that early era, the exhaust steam from the engines was not wasted but was used for heating the station building. There was no breakdown service provided from the New York Edison Company, which indicates complete faith in the reliability of the generating plant itself. The switchboard controlling the outputs of the generators must have been elaborate and impressive. Unfortunately, no known photos of it survive, but it was said to have been constructed of Tennessee marble.

Grand Central Terminal

The earlier Grand Central facilities featured surface train yards necessitated by the use of steam locomotives. As time went on and rail traffic increased, the noise and dirt associated with these surface operations became more obnoxious for residents to the east and west of the yards.

All train traffic in and out of Grand Central has always been from the north only (this will soon change with the completion of the East Side Access project, which will allow trains access to Grand Central Terminal from Long Island). By the end of the 19th century, the four main Grand Central tracks had been placed in a tunnel beneath Park Avenue, north of the train yards, to improve the environment along upper Park Avenue.

The continued use of steam locomotives in the Park Avenue tunnel led inevitably to a horrific crash due to the inability of a locomotive engineer to see a red signal because of the excessive smoke in the tunnel. This event occurred in 1902 and, as a result, the City of New York decided to ban the use of steam locomotives on Manhattan Island by 1 July 1908.

The New York Central Railroad placed the responsibility for a solution to this problem in the hands of a young civil engineer named William Wilgus, who had joined the railroad in 1893 and was named chief engineer in 1899. Wilgus and the Electric Traction Commission (ETC), an independent panel of experts that he appointed in late 1902 and chaired, developed the brilliant solution to electrify all train operations at Grand Central and on the New York Central Railroad and related rail lines into New York City. This solution would allow the train yards to be relocated beneath the surface and, thereby, to open up the remainder of Park Avenue for development.

Wilgus convinced the New York Central Railroad that it was futile to attempt to adapt the existing Grand Central Station for this new mode of operation and that the funds simply had to be spent to start over and construct an entirely new terminal. The result of that decision led to the present day Grand Central Terminal, which opened in 1913 (the existing surface tracks had been electrified temporarily to meet the 1908 deadline).

The electrification was to be dc at approximately 600 V distributed via third rails with one track rail serving as the return. Eventually, this power system was extended through the Bronx and into Westchester County to the north. The entire installation was designed by the General Electric Company and included special electric locomotives (known as “electric motors” or “S motors”) to replace steam locomotives.

Since the previous Grand Central facilities had been chronically overcrowded in spite of almost continual enlargements of the station, Wilgus also convinced the New York Central executives to construct a truly huge new facility. It included two underground track levels, the upper for long distance trains and the lower for local suburban (commuter) trains. There would be a total of 49 tracks at platforms (32 on the upper level and 17 on the lower level). The track configurations in the two yards would be incredibly complex. The two main interlocking machines for controlling switches and signals to avoid the possibility of a collision had a total of 760 operating levers, 360 for the upper level and 400 for the lower level.

figure 2. The Glenwood Power Station along the Hudson River in Yonkers, New York (photo courtesy of the Museum of Innovation and Science (miSci) Archives, Schenectady, New York).

figure 2. The Glenwood Power Station along the Hudson River in Yonkers, New York (photo courtesy of the Museum of Innovation and Science (miSci) Archives, Schenectady, New York).

The New Power Houses

Two large steam generating stations were constructed to supply third-rail power for the newly electrified Grand Central operation. One station was located in the Port Morris section of the Bronx and the other in the Glenwood section of Yonkers in Westchester County to the north. These stations generated 11,000-V, three-phase, 25-Hz alternating current (ac) power that was distributed to a series of rotary converter substations located along the routes of the railroad. The rotary converter substations, in turn, provided 600–650-V dc for the third rails (see Figure 2).

The Port Morris Station is long gone, but the Glenwood Station survives today. It is in derelict condition, but the most recent of a long series of attempts to renovate it for adaptive reuse is currently underway.

In addition, a service plant was constructed along the east side of Park Avenue between 49th and 50th Streets, and this came to be known as the “50th Street Plant.” Its location was actually above part of the underground train yards north of Grand Central.

One function of this service plant was to supply both steam and hot water to Grand Central Terminal and to buildings located adjacent to it and along Park Avenue to the north. These services were necessary because the underground train yards eliminated the possibility of these buildings having basements to contain their own boiler rooms.

figure 3. Steam turbine generators for light and power at 50th Street (photo courtesy of the Museum of Innovation and Science (miSci) Archives, Schenectady, New York).

figure 3. Steam turbine generators for light and power at 50th Street (photo courtesy of the Museum of Innovation and Science (miSci) Archives, Schenectady, New York).

The 50th Street plant also generated electric power for lighting and motor use within the terminal. Three steam-turbine-driven 500-kW, 275-V dc generators were installed for this purpose (see Figure 3).

Originally, ten boilers were installed, having a total capacity of 6,000 boiler hp. However, space was provided for the possible future addition of at least 14 more such boilers. In 1913, this plant was providing steam and hot water to a total of 28 buildings in the area bounded by 42nd Street and 50th Street and by Lexington and Madison Avenues to the east and west, respectively.

Apparently, the additional boilers were soon added at the 50th Street plant because it was reported to have reached its capacity by 1918. A second steam plant was then constructed in that year to provide additional capacity. This was located in a large excavated area beneath Grand Central Terminal itself. The necessary smokestack for this boiler plant was run up through the northwest corner of the adjacent Commodore Hotel, which happened to be under construction at the same time.

This plant consisted of four operating floors, all below street level. The basement was used for the handling of ashes from the boilers located on the main floor above. A room devoted to the metering of the steam supplied was located above the boiler floor, and above that were the coal bunkers that were supplied from the street.

The 50th Street Substations

figure 4. The interior of traction Substation No. 1 at 50th Street (photo courtesy of the Museum of Innovation and Science (miSci) Archives, Schenectady, New York).

figure 4. The interior of traction Substation No. 1 at 50th Street (photo courtesy of the Museum of Innovation and Science (miSci) Archives, Schenectady, New York).

Rotary Converter Substation No. 1 for third-rail power was originally located adjacent to the 50th Street service plant. Ultimately, it contained a total of seven rotary converters of various sizes, which aggregated 14,500 kW of 600-V dc traction power (see Figure 4).

In addition, there was an adjoining substation to supplement the three 275-V dc turbine-driven generators for the supply of lighting power. This was designated as Substation No. 1A, and it contained four 1,500-kW rotary converters that also operated from the high-voltage power supplied by the Port Morris and Glenwood power stations.

An adjacent battery house contained an 8,000-Ah rated battery to act as an emergency backup for the 250-V dc lighting supply. A “balancer set” consisting of two identical coupled 125-V dc generators (with either one acting as a motor at any given time) provided a derived neutral connection for 125-V lighting.

Substation No. 1 was completed first, in 1906, to provide third-rail power to meet the imposed 1908 deadline for the elimination of steam locomotive usage. The service plant for the supply of steam and hot water was not completed until 1910. Its turbine-driven dc generators then supplied all power for lighting until the completion of Substation No. 1A in 1913.

The Loss of the 50th Street Power House

A major facet of the plan for a new Grand Central Terminal as set forth by William Wilgus was the development of the air rights above the underground train yards along a reconstructed Park Avenue. The revenue to the New York Central Railroad resulting from the eventual sale of these air rights would pay for a large portion of the new terminal construction.

In 1929, the original Waldorf and Astoria Hotels on Fifth Avenue between 33rd and 34th Streets were demolished to allow for the construction of the Empire State Building. These hotels (which actually were physically connected) had been built during the 1890s by two feuding cousins: John Jacob Astor IV and William Waldorf Astor.

Grand Central’s 50th Street power house had become something of an eyesore along the developing Park Avenue. Consequently, the New York Central Railroad decided to sell that parcel of land for the construction of a new Waldorf-Astoria Hotel. This was made possible by a decision to eliminate the production of steam for the terminal and adjacent buildings. Instead, the required steam would be purchased from the New York Steam Corporation, which operated a boiler house on the East River at a location known as Kips Bay, several blocks south of Grand Central.

The purchased steam, by the way, would be distributed using a series of already existing tunnels beneath the lower-level Grand Central train yard. In later years, those tunnels would become notorious as the warm shelters used during the winter by some of New York City’s many homeless people.

This decision also eliminated the need for the steam plant located beneath Grand Central itself. Therefore, it was possible to renovate this large area for the construction of a new substation that would replace both Substation No. 1 and Substation No. 1A at 50th Street.

The Big Move

The purchase of all new electrical equipment for this new substation would have been a waste of money since most of the existing equipment at 50th Street was still perfectly usable. Consequently, a plan was devised to move this equipment to the former steam plant space.

Of course, train service could not be disrupted during such a move. Therefore, a new underground circuit breaker house was constructed at 49th Street to feed the 36 existing feeder cables that supplied power to all of the third-rail sections in the underground train yards. This installation was supplied from the still operating Substation No. 1 at 50th Street, and 12 new main cables were installed to it from the new substation location beneath the terminal. As rotary converters and other equipment were gradually moved from Substation No. 1 to the new substation (designated as Substation “1T”), these newly installed circuit breakers allowed individual third-rail feeder cables to be reconnected as desired.

It was impractical to consider moving all of this heavy electrical equipment on the surface streets. Instead, pieces of equipment were lowered through a hatchway in the floor of the old Substation No. 1, using its overhead traveling crane, to flat cars located on tracks in the upper level train yard beneath.

Incidentally, one of these tracks that still exists beneath the present Waldorf-Astoria Hotel (designated as Track 61) is said to have been used by President Franklin Delano Roosevelt as a convenient nonpublic access to the hotel after traveling by rail from his home in Hyde Park, New York, to the north. This tactic helped with the constant struggle to keep public attention diverted from his need for a wheelchair due to his affliction with polio.

The flat cars containing electrical equipment were maneuvered to the lower-level train yard at designated hours of the day so as not to unduly interrupt normal train traffic. Then, beneath the terminal, the pieces had to be lowered through another hatchway a distance of 50 ft (15.2 m) to the floor of the new substation space. Temporary rope block-and-tackle arrangements were used for lowering parts at both locations, and a total of 850 tons (863.6 metric tons) of electrical equipment was eventually moved in this manner. A new 35-ton (35.6-metric ton) overhead traveling crane was used to reassemble the rotary converters and other equipment in Substation 1T.

The space just above the new Substation 1T, which formerly had served as a steam supply metering room, was adapted to house ventilating fans to circulate air through the substation below. The exhaust air was then directed up what originally had been the smokestack built into the corner of the Commodore Hotel.

Additional space was carved out beneath the adjoining Graybar Building to house heaters and pumps utilizing part of the now-purchased steam to produce hot water and circulate it throughout the terminal and to neighboring buildings.

The space above the ventilating room over Substation 1T, which originally had contained coal bunkers for the boilers below, was adapted as a new home for the backup battery from the 50th Street battery room. In this case, the battery sections actually had to be raised from the lower track level along which they had been transported from 50th Street, since the former coal bunker space was located just below street level.

figure 5. An overview of Substations 1T and 1L from the east end (photo courtesy of Gerald Weinstein, photographer).

figure 5. An overview of Substations 1T and 1L from the east end (photo courtesy of Gerald Weinstein, photographer).

The battery consisted of 160 cells, each of which measured 7 ft (2.13 m) in length by 2 ft (0.61 m) in width and stood about 3-ft (0.91-m) high. Each cell, containing lead plates and filled with sulfuric acid solution, weighed 4,550 lb (2,063.8 kg). Not only was it impractical to move these cells at street level, it was also illegal to transport open acid containers along the street. Each cell was jacked up and mounted onto a trailer that then was towed by a battery-powered tractor (ironically) to another hatchway in the floor of the 50th Street substation. The cell, on its trailer, was then lowered by block and tackle a distance of 55 ft (16.8 m) to a trucking “subway” associated with the lower train yard level. It was then towed, using another electric tractor, south to the terminal along a wide trucking platform that ran along the east side of the lower yard. There, an existing elevator was used to raise it to the level of the former coal bunker space, now the battery room.

This complex moving operation was begun in March 1929 and was completed, ahead of schedule, by Christmas of that year. The operation was under the direction of F.B. Freeman, the chief engineer of the New York Central Railroad. The actual work was performed by the Thompson-Starrett Contracting Company and was carried out with the assistance of engineers from the General Electric Company.

figure 6. The 600-V traction (third rail) rotary converters in Substation 1T (photo courtesy of Gerald Weinstein, photographer).

figure 6. The 600-V traction (third rail) rotary converters in Substation 1T (photo courtesy of Gerald Weinstein, photographer).

The New Substations

The cavernous space occupied by the former steam plant beneath Grand Central Terminal was functionally divided in two. The eastern half was devoted to the installation of 600-V rotary converters to supply dc traction power to the third rails and was designated Substation 1T. The western half was devoted to 250-V rotaries for dc lighting and general power in the terminal and was designated Substation 1L.

Substation 1T contained five rotary converters, three of which had been moved down from 50th Street, including one fairly new 4,000-kW converter. The other two were 4,000-kW machines constructed by General Electric for this new facility, and the total capacity provided was 16,500 kW (see Figures 5–8).

Similarly, Substation 1L contained five converters, four of these being 1,500-kW machines from 50th Street, plus one new 2,000-kW machine, for a total of 8,000 kW.

figure 7. Main positive dc breakers on the Substation 1T switchboard (photo courtesy of Gerald Weinstein, ­photographer).

figure 7. Main positive dc breakers on the Substation 1T switchboard (photo courtesy of Gerald Weinstein, ­photographer).

To the north of this space, another substation (designated “1B”) had been in operation since before 1927 to also provide 250-V dc power, not only for the terminal but for the Graybar Building above it and for the Commodore Hotel as well. This installation consisted of four 2,000-kW rotaries plus an adjacent battery room.


In 1989, Robert Walker very kindly arranged for the author to tour the substation areas beneath the terminal. The last of the Substation 1T rotary converters had just been shut down a few weeks prior to this. Three more traction rotaries were still in place, and two of these were in the process of being dismantled. Only two or three of the original five rotaries had been operational in the years prior to this, which had led to necessary overloading of the machines during morning and evening rush hours when the heavier train traffic required additional third-rail power.

All of the Substation 1L rotaries had been replaced by a series of 660-V solid-state rectifier units to supply third-rail power since, by this time, there was no longer any need for 250-V dc lighting and power. In Substation 1B, only one of the original rotaries was still in place, and it had been out of operation for some time.

The fifth traction rotary had experienced a spectacular demise in March 1988. It failed catastrophically and threw hot metallic shrapnel around the substation. Fortunately, there were no injuries, but the New York City Fire Department was kept busy for a while putting out small fires caused by flying debris. This event served to hasten the process of bringing the three new 3,300-kW solid-state traction rectifier units online.

figure 8. The 250-V dc lighting and power feeder board in Substation 1L (photo courtesy of Gerald Weinstein, photographer).

figure 8. The 250-V dc lighting and power feeder board in Substation 1L (photo courtesy of Gerald Weinstein, photographer).

Since not all of the available space in Substation 1T was required for the installation of the solid-state rectifiers, at least one of the 4,000-kW traction rotaries has been saved in place for posterity.


The author is indebted to Gerald Weinstein, CEO of General Tools & Instruments in Manhattan, for providing photographs and other information regarding Substation 1T; to Chris Hunter and staff of the Museum of Innovation and Science (MiSci) Archives in Schenectady, New York, for early photographs; and to Robert Walker for additional information regarding operation in later years.

For Further Reading

J. J. Cunningham and J. L. Sprague, “A Frank Sprague triumph: The electrification of Grand Central Terminal,” IEEE Power Energy Mag., vol. 11, no. 1, pp. 58–76, Jan.-Feb. 2013.

Unpublished and undated write-up (author unknown) on the electrical history of Grand Central by the New York Central Railroad, obtained from ­Robert Walker in 1989.

A. W. Robins and the New York Transit Museum, Grand Central Terminal: 100 Years of a New York Landmark. New York: Stewart, Tabori & Chang, 2013.

“The heating and lighting equipment of the Grand Central Station,” Elect. World, vol. 32, no. 14, pp. 339–340, Oct. 1, 1898.

“New terminal for New York central lines,” Elect. World, vol. 60, no. 25, pp. 1309–1318, Dec. 21, 1912.

“Electrification by G.E.,” Bulletin 116 of the Central Electric Railfans’ Association, Chicago, 1976. (Reprint of a 1929 publication by permission of the General Electric Company.)

“Power and heat for the Grand Central Terminal area,” Railway Age, pp. 632–634, Mar. 15, 1930.

F. B. Freeman, “Moving a substation underground,” Scientific American, vol. 142, no. 6, pp. 458–459, June 1, 1930.

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