IRT Powerhouse

IRT Powerhouse
Company type	Historic power generation facility
Industry	Power generation, Transportation infrastructure
Founded	1902
Founder	Interborough Rapid Transit Company
Defunct	1959 (as a subway power source)
Fate	Incorporated into New York City steam distribution network by Consolidated Edison
Headquarters	Manhattan, New York City, United States
Area served	New York City Subway system (historically)
Key people	Stanford White (architect), John van Vleck (engineering), Lewis B. Stillwell (engineering), S. L. F. Deyo (engineering)
Products	Electricity for subway system, later steam distribution
Parent	Interborough Rapid Transit Company (original), New York City Board of Transportation (post-1940), Consolidated Edison (post-1959)

The IRT Powerhouse, also referred to as the Interborough Rapid Transit Company Powerhouse, is a historic power generation facility originally constructed for the Interborough Rapid Transit Company (IRT), the operator behind the first line of the New York City Subway. This building occupies an entire city block bordered by 58th Street, 59th Street, Eleventh Avenue, and Twelfth Avenue within Manhattan’s Hell's Kitchen and Riverside South districts.

Conceived in the Renaissance Revival architectural style by Stanford White of McKim, Mead & White, the powerhouse was designed as a striking aboveground structure for the IRT. Its exterior is constructed with granite, brick, and terracotta, richly adorned with ornamental detailing. The engineering design of the interior was led by John van Vleck, Lewis B. Stillwell, and S. L. F. Deyo. At its operational peak, the powerhouse produced over .

Land for the site was acquired in late 1901, with construction spanning from 1902 until 1905. Throughout the early to mid-20th century, the facility underwent several alterations, including the addition of a western extension completed in 1950. Following the IRT’s takeover by the New York City Board of Transportation in 1940, the powerhouse continued to supply electricity to the subway system until 1959. Thereafter, Consolidated Edison incorporated it into New York City’s steam distribution network. After prolonged advocacy, the building was officially designated a city landmark by the New York City Landmarks Preservation Commission in 2017.

Site

Situated on Manhattan’s West Side, the IRT Powerhouse straddles the boundary between the Hell's Kitchen and Riverside South neighborhoods in New York City. Its address ranges include 855–869 Eleventh Avenue, 601–669 West 58th Street, and 600–648 West 59th Street. The structure occupies a full block enclosed by 59th Street to the north, 58th Street to the south, Eleventh Avenue on its eastern edge, and Twelfth Avenue alongside the Hudson River to the west. This block covers roughly , positioned just south of Waterline Square. Upon its completion, the powerhouse presented a 200-foot-wide facade along Eleventh Avenue and extended westward for 694 feet, terminating with a provisional brick wall.

Architecture

The IRT Powerhouse is an intricately designed example of Renaissance Revival architecture created by Stanford White, a leading architect from McKim, Mead & White. The building’s interior engineering was overseen by John van Vleck, Lewis B. Stillwell, and S. L. F. Deyo, while John B. McDonald directed machinery placement and overall layout. Structural engineering responsibilities were handled by William C. Phelps, noted for his prior work on Manhattan Railway Company’s 74th Street Power Station.

Members of IRT’s board took an active role in shaping the building’s facade, choosing an elaborate style consistent with prominent civic architecture of that era to ensure visual distinction. The design embodies ideals from the City Beautiful movement, aiming to create not only a functional power source but also a monumental urban landmark. As the electricity provider for the original Interborough Rapid Transit Company subway line, this powerhouse was intended as a visible symbol of infrastructure akin to major transit centers such as Grand Central Terminal or St Pancras railway station.

Form

The IRT Powerhouse was organized into two main sections along its west-to-east axis: the boiler room located on the southern side facing 58th Street, and the engine and generator area positioned on the northern side facing 59th Street. The boiler room spanned 83 feet in width, while the operating plant extended 117 feet across. An annex was constructed at the far western end of the block, completed in 1951.

Rising 125 feet above the basement level, the roof featured multiple pitched gables set back from the street frontage. Initially, the roof was covered with terracotta and incorporated a substantial glass clerestory. Upon opening, the facility included five brick smokestacks designed to mimic those found on nearby Hudson River steamships. Each smokestack weighed approximately 1,160 short tons and reached a height of 162 feet above the roof (225 feet above the boiler grates), spaced evenly at 108 feet apart and constructed with thick brick walls. At the roof line, their diameter was 21 feet, tapering to 15 feet at the top. Shortly after completion, a sixth smokestack of similar design was added. All original smokestacks have been removed since then; only a seventh smokestack, erected in 1967, remains atop the building.

Facade

The powerhouse’s facade is structurally independent from its interior framework. The base of the building is faced with Milford granite on its northern, southern, and eastern sides. The upper levels are clad in brick and terracotta, arranged vertically into distinct bays. Each bay—except for those at the outer edges—features double-height round-arched windows on the second and third floors, crowned by decorative archivolts and scrolled keystones, mostly fitted with latticed window frames. The outermost bays contain two rectangular windows per floor. Ornamental horizontal friezes run above both the first and third floors, with an additional course above the fourth story. The original cornice has since been removed. The overall facade design draws inspiration from the Boston Public Library, incorporating exaggerated architectural elements.

The most ornate section faces Eleventh Avenue and consists of eight bays. The central six bays slightly project forward and are bordered by brick and terracotta pilasters topped with glass transom panels interspersed with regularly placed palmette motifs. These pilasters align vertically with where the original chimneys once stood. The northernmost bay contains the original main entrance—a rectangular doorway framed with classical detailing. On the attic level of the fourth story are pairs of rectangular windows set within decorative surrounds, topped by a parapet featuring a tablet. A planting bed enclosed by an iron railing separates this facade from the sidewalk; this space was originally designed as a sunken basement courtyard.

Both the southern elevation along 58th Street and northern elevation along 59th Street extend across nineteen bays each but exhibit subtle differences. The 58th Street facade includes basement-level openings and buff brick transom panels above arched openings; in contrast, the 59th Street side lacks basement apertures and instead has glazed glass transoms. Bays on both sides are divided by paired rusticated brick pilasters accented with simple banding. The attic story on these elevations contains groups of three rectangular windows framed decoratively, except for paired windows in the outermost bays. The easternmost bays on both facades incorporate portals that were originally used for freight trains operated by New York Central Railroad along Eleventh Avenue; this rail line was subsequently relocated to what is now known as the West Side Line. Several base-level openings are fitted with roll-down metal gates.

Structural characteristics

The structure is upheld by a steel skeletal framework weighing approximately . The floors and coal storage areas utilize I-beams and plate girders similar to those found in plate girder bridge construction, necessitating girders of bridge-grade strength due to the steel specifications. Steel materials were provided by the American Bridge Company. Floor girders are positioned below the surface, supported by connecting beams underneath, which rest on riveted "seats" fastened to the webs of the girders. Column girders vary according to load requirements; columns supporting cranes are reinforced with cantilevered elements.

Concrete arches reinforced with expanded metal mesh form the floors, featuring slabs at least thick. These are engineered to endure test loads of on flat roof sections, within the engine room, and in the boiler section. The engine room includes an additional slate slab floor resting on brick partitions above the concrete arches, with its primary operational floor situated on a mezzanine level above the boiler house floor. Separate column frameworks support the roofs over both the operating and boiler areas. The original chimneys were anchored on platforms constructed from I-beams and deep plate girders.

Due to uneven bedrock depths ranging from , the foundation employs multiple construction techniques. Cast-iron bases distribute loads from superstructure columns; where bedrock was near the surface, these bases rest on thick concrete pads. Some foundations are founded on concrete piers capped with granite blocks. Each of the twelve engine positions is supported by substantial granite bases. In total, the foundation accommodates 397 superstructure columns.

Equipment and operations

The layout of the IRT Powerhouse followed a design typical for large-scale power plants. A brick partition separated the boiler room from the engine-generating room to contain any steam failures. Electrical switches and controls were installed in galleries along the north wall, while auxiliary steam piping and maintenance equipment were mounted on the south wall. Operations benefited from several traveling cranes. Upon completion, it was intended to be the largest generating station globally.

Boilers

John van Vleck designed the boiler system as six independent units to enhance operational flexibility. Each unit comprised twelve boilers arranged in two rows, supplying steam to two engines, along with condensers, boiler-feed pumps, smoke flue systems equipped with economizers, and auxiliary machinery. Five units were uniform in design; the sixth contained a steam turbine dedicated to powering subway tunnel illumination. Boiler feedwater was sourced from city mains. The boilers were arranged on a single level with economizers positioned above, optimizing space utilization and ventilation under a ceiling height of 35 feet.

The powerhouse consumed around 1,000 short tons of coal daily, producing 132,000 horsepower. Coal deliveries arrived via a 700-foot pier along Twelfth Avenue and were conveyed to basement storage through conveyor belts. Seven coal bunkers located above the boilers—each separated by chimneys—stored coal supplies; vertical conveyors distributed coal evenly among them. This arrangement allowed for multiple coal grades to be used: higher-grade coal during peak demand periods and lower-grade coal at other times. Ash produced during combustion fell into hoppers beneath the boilers; locomotives transported ash hoppers to conveyors that sorted ashes for either barge loading or storage in bunkers.

Engines

Steam generated by each set of six boilers was directed into a steam main, which either supplied the high-pressure cylinders located in the basement or fed into a 12-inch pipe manifold linking all boiler groups. Valves enabled the operation of individual boiler/engine groups independently or allowed steam to be distributed evenly among engines situated in the generating room.

The engines consisted of 12,000 hp reciprocating units, each pair including both high and low pressure cylinders. Two barometric jet condensers were assigned to each engine, utilizing filtered water from the Hudson River to condense steam. The condensate water was discharged back into the river, as the jet condensers prevented the reuse of steam as boiler feedwater. Each of these twelve condensers handled a capacity of 10 million gallons daily.

Generators

Nine flywheel-type alternating current generators, each rated at 5,000 kW and operating at 75 rpm, were directly coupled to the steam engines. This configuration provided an optimal balance between large capacity and mechanical dependability, requiring only two bearings and accommodating load variations during peak periods efficiently. These generators produced three-phase, 25-cycle alternating current at 11,000 volts.

Electric current flowed through switchboards to eight substations distributed throughout Manhattan and the Bronx. Large oil-operated high-tension switches located on the plant’s main gallery enabled circuit interruption. The substations converted AC power to 600 volts DC to supply the third rail system used by trains.

Among the AC generators were four turbo generators rated at 2,000 hp each; three were operational upon plant completion. Each turbo generator was powered by a 1,250 kW alternator supplying station lighting and, combined with the AC generators, contributed to a total output of 100,000 hp. Additionally, five DC exciters rated at 250 kW each provided excitation current for rotating fields—three driven by induction motors and two powered by 400 hp marine-type steam engines.

History

The initial planning for the city’s inaugural subway line commenced with the Rapid Transit Act passed by the New York State Legislature in 1894. Engineers led by William Barclay Parsons, chief engineer of the Rapid Transit Commission, developed subway plans that were formally adopted in 1897. In February 1900, the Rapid Transit Subway Construction Company (RTSCC), established by John B. McDonald and financed by August Belmont Jr., signed Contract 1 with the Rapid Transit Commission to build and operate the subway under a 50-year lease agreement. Belmont founded the Interborough Rapid Transit Company (IRT) in April 1902 to oversee subway operations.

Planning and construction

The RTSCC was tasked with constructing and operating a steam-powered powerhouse for subway operations. Ideal locations required proximity to coal transport routes and adequate water supply, making riverside sites preferable. Parsons advocated for a Midtown Manhattan location near the subway’s distribution hub, dismissing options in Lower Manhattan and Long Island City. By mid-September 1901, RTSCC had contracted Allis-Chalmers for engines and Babcock & Wilcox for boilers at a combined cost of $1.5 million. Shortly thereafter, McDonald acquired land bounded by 58th Street, Eleventh Avenue, 59th Street, and Twelfth Avenue for $900,000.

Following this purchase, Belmont, Deyo, McDonald, and van Vleck traveled to Europe to examine railway power facilities. Architect Stanford White was engaged to design the powerhouse; his plans were finalized by February 1902. Originally planned as a concrete structure, brick was ultimately chosen after bricklayers threatened labor action. The building’s length was extended from 586 feet to 694 feet following IRT’s signing of Contract 2 that same year. Plans were submitted to the New York City Department of Buildings in May 1902.

Despite multiple labor strikes, construction advanced swiftly. By late 1903, subway completion was near but labor disputes postponed its opening. During these delays, IRT considered obtaining power from the Metropolitan Street Railway's powerhouse on 96th Street. In January 1904, negotiations successfully prevented strikes after subcontractors employed nonunion laborers. By April of that year, over four hundred workers were engaged in powerhouse construction; most of the structure was finished except for its western section. Two months later, it was described as "the largest [...] project in the city actually under construction."

Subway powerhouse

The 59th Street powerhouse, part of the IRT, commenced operations on October 27, 1904, coinciding with the launch of the initial subway line. This facility was among the last projects designed by architect White before his passing in 1906. At the outset, one of the six boiler and engine units was not operational but became functional by late 1904 or early 1905. Adjacent to the powerhouse’s western side, a separate storage facility was established. Shortly after opening, the IRT implemented a coal analysis laboratory at the unloading dock to monitor fuel quality, enhancing furnace efficiency and overall plant output.

By 1907, rapid expansion of the IRT required increased capacity, prompting the installation of additional stokers that raised boiler output by 50%, alongside upgrades to eighteen boilers. In preparation for system enlargement under the 1913 Dual Contracts, five vertical turbo-generators rated at 7,500 kW each and surface condensers were installed between 1909 and 1910, boosting generating capacity by 15,000 kW without needing more steam heating. From 1913 to 1917, stokers were replaced to improve operational efficiency. The year 1917 saw the addition of three horizontal GE turbo-generators rated at 35,000 kW each and superheaters for thirty boilers. A centralized control service launched in 1915 coordinated operations at both the 59th and 74th Street plants along with multiple substations. After a coal shortage caused a power outage in 1917, regulations mandated maintaining coal reserves at both facilities. Four new boilers equipped with underfeed stokers were added in 1924; no significant enhancements occurred over the next sixteen years.

In 1940, ownership of the IRT transferred to the New York City Board of Transportation (BOT), integrating it with other subway lines. The BOT assumed control of the 59th Street plant, which by that time contained outdated boilers that limited train speeds. To remedy this issue, an expansion westward toward Twelfth Avenue was approved in 1946 with a $655,000 contract awarded in 1948. Completed in 1950, this annex introduced one highly efficient boiler with a capacity of 62,500 kW that consumed only one-third the coal compared to older units and replaced existing switchgear equipment. A circuit testing procedure in 1951 temporarily interrupted subway operations. That same year, responsibility for running the plant shifted from BOT to the New York City Transit Authority (NYCTA).

Sale

By the mid-1950s, much of the equipment within the 59th Street powerhouse had become outdated and contributed significantly to pollution levels; many components had remained unchanged since its original construction. The NYCTA estimated that approximately $200 million would be necessary to modernize its three transit powerhouses. Discussions arose advocating for NYCTA to divest these plants. In November 1956, Mayor Robert F. Wagner Jr. proposed selling them to Consolidated Edison (Con Ed), although this suggestion met opposition from the Transport Workers Union of America. Early in 1957, NYCTA urged Wagner to decline Con Ed’s initial $90 million bid over concerns that a low sale price might trigger fare hikes.

A revised offer from Con Ed emerged in April 1958 at $123 million; after receiving guarantees that fares would not increase, NYCTA withdrew its objections. By February 1959, Con Ed increased its proposal to roughly $126 million, and the New York City Board of Estimate approved the transaction in March. Although an unidentified investor consortium also expressed interest, Con Ed ultimately purchased all three plants at auction in May 1959 as the sole bidder. This sale released $9.26 million previously earmarked for plant upkeep, enabling NYCTA to allocate funds toward acquiring additional subway cars.

Later years

Following the acquisition of the transit power plants, Con Ed launched an extensive modernization initiative. The 59th Street facility underwent significant renovations to support the New York City steam system. Oil shipments to Pier 98 fueled the former IRT Powerhouse operations. By 1960, older low-pressure boilers were replaced with advanced high-pressure models, which lowered the workforce from 1,200 to fewer than 700 employees and introduced topping turbines. Additional enhancements included installing extra boilers, a turbo-generator in 1966, and consolidating four chimneys into a single smokestack. By 1968, the plant's fuel sources were limited exclusively to oil and gas.

The New York City Landmarks Preservation Commission (LPC) initially evaluated the IRT Powerhouse for landmark designation in 1979. While historian John Tauranac and various preservation advocates supported this effort, Con Ed opposed it except for preserving the Eleventh Avenue facade. Renewed LPC hearings in 1990 and public campaigns in 2007 revived the push for landmark status; however, Con Ed's resistance—citing substantial alterations to the structure—prevented official designation. Even after receiving hundreds of supportive public comments during a 2009 review, LPC declined to grant landmark status due to continued opposition from Con Ed.

Efforts to preserve the powerhouse persisted into the mid-2010s as the LPC prioritized it among long-delayed landmark considerations. Public hearings demonstrated widespread support for protection, yet Con Ed remained the only dissenting party. As a result, LPC postponed formal designation while negotiating preservation approaches that would accommodate ongoing plant operations. Ultimately, on December 5, 2017, the powerhouse was officially designated a city landmark, followed by LPC’s approval of a restoration plan in January 2018.

Though it ceased power generation, the IRT Powerhouse continued to function within a steam network supplying approximately 1,500 buildings in Manhattan; as of 2022, the nearby 59th Street steam plant accounted for roughly 12 percent of this capacity. Over time, oil deliveries to Pier 58 decreased significantly, leading to increased dependence on natural gas pipelines. By 2022, the steam system’s fuel composition consisted of about 3 percent oil and 97 percent natural gas.

Reception

At the time of the subway’s inauguration, an engineer remarked that its design evoked the appearance of a public library or art museum. The building has since maintained critical acclaim; a New York Times writer in the 1990s described the IRT Powerhouse as a "thoroughly classical colossus of a building." Clifton Hood, author of a comprehensive history of the New York City Subway published in 2004, characterized it as "a classical temple that paid homage to modern industry." Notable architects, historians, and artists—including Robert A. M. Stern, Barry Bergdoll, Andrew Dolkart, and Chuck Close—have expressed admiration for the structure in letters submitted to the Landmarks Preservation Commission.

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