The IRT Powerhouse, also known as the Interborough Rapid Transit Company Powerhouse, is a former power station of the Interborough Rapid Transit Company (IRT), which operated the New York City Subway's first line. The building fills a block bounded by 58th Street, 59th Street, Eleventh Avenue, and Twelfth Avenue in the Hell's Kitchen and Riverside South neighborhoods of Manhattan, New York City, United States.
The IRT Powerhouse was designed in the Renaissance Revival style by Stanford White, an architect working with the firm McKim, Mead & White, and was intended to serve as an aboveground focal point for the IRT. The facade is made of granite, brick, and terracotta, incorporating extensive ornamentation. The interiors were designed by engineers John van Vleck, Lewis B. Stillwell, and S. L. F. Deyo. At its peak, the powerhouse could generate more than .
The land was acquired in late 1901, and the structure was constructed from 1902 to 1905. Several changes were made to the facility throughout the early and mid-20th century, and an annex to the west was completed in 1950. The New York City Board of Transportation took over operation of the powerhouse when it acquired the IRT in 1940. The building continued to supply power to the subway system until 1959, when Consolidated Edison repurposed the building as part of the New York City steam system. The New York City Landmarks Preservation Commission designated the powerhouse as a city landmark in 2017, after several decades of attempts to grant landmark status to the building.
Site The IRT Powerhouse is on the border of the Hell's Kitchen and Riverside South neighborhoods on the West Side of Manhattan in New York City, United States. It carries the addresses 855–869 Eleventh Avenue, 601–669 West 58th Street, and 600–648 West 59th Street. The building fills the entire block bounded by 59th Street to the north, 58th Street to the south, Eleventh Avenue to the east, and Twelfth Avenue and the Hudson River to the west. The block measures about and is just south of Waterline Square. When it opened, the IRT Powerhouse had a frontage of along Eleventh Avenue and extended westward, with a temporary brick wall at the western end.
Architecture The IRT Powerhouse is an elaborately detailed Renaissance Revival building, designed by Stanford White, one of the principal architects of the firm McKim, Mead & White.; ; ; The interiors were designed by the IRT's managing engineers John van Vleck, Lewis B. Stillwell, and S. L. F. Deyo. The machinery and internal layout were designed by IRT engineer John B. McDonald. The structural design is largely attributed to William C. Phelps, who had also been involved in constructing the Manhattan Railway Company's 74th Street Power Station between 1899 and 1901.
The IRT's directors were personally involved in designing the IRT Powerhouse's facade. According to an IRT history, the directors decided on "an ornate style of treatment" similar to that of other civic projects of the time, while also rendering the building "architecturally attractive".; ; The building's magnificence and ornate details reflect the ideas of the City Beautiful movement. The powerhouse provided power for the original subway line of the Interborough Rapid Transit Company (IRT). It and served as an aboveground focal point for the system, akin to Grand Central Terminal or St Pancras railway station.
Form As constructed, the IRT Powerhouse was separated transversely into two sections, both running along the west–east length of the building. The boiler room was on the south, facing 58th Street, while the operating plant with the engines and generators were on the north, facing 59th Street.; ; ; The section allocated to the boiler room was wide, while that allocated to the operating plant was wide.; ; The westernmost section of the block is occupied by an annex completed in 1951.
The roof above the IRT Powerhouse is above its basement. The roof consists of several smaller pitched gables set back from the street. The roof was initially clad with terracotta and contained a large glass clerestory.; ; The building opened with five brick smokestacks, designed to echo the smokestacks on the great steamships at the nearby Hudson River piers. These chimneys weighed apiece and rose above the roofs, or above the grates in the boiler rooms. The smokestacks were spaced apart and were lined with thick layers of brick.; ; The chimneys measured across at the roofline and across at their tops. A sixth smokestack, similar to the others was added shortly after the powerhouse was completed. All of these original smokestacks have been demolished. A seventh smokestack, built in 1967, remains on the building's roof.
Facade
The facade of the powerhouse is self-supporting and independent of the interior.; ; ; The base of the powerhouse is clad with Milford granite along its northern, southern, and eastern elevations. The upper stories are clad with brick and terracotta and are divided vertically into bays.; ; ; On the second and third stories of each bay (except for the outermost bays on each side), there are double-height round-arched window openings topped by decorative archivolts and scrolled keystones. These arched window openings largely contain latticed window frames. In the outermost bays, there are two rectangular windows on either of the second and third stories. There are ornamented horizontal friezes running above the first and third stories and a course above the fourth story. The facade was capped by a cornice, which was later removed. The overall design of the facade is based on the Boston Public Library, but with over-scaled design elements.
The most elaborately designed section of the building's facade is the eastern elevation facing Eleventh Avenue, which consists of eight bays. The six center bays project slightly and are flanked by brick and terracotta pilasters. Within these six bays, the tops of the arched openings contain transom panels made of glass. There are palmettes placed at regular intervals along the pilasters. The pilasters correspond exactly to the original chimneys. The northernmost bay, the furthest right along the Eleventh Avenue facade, contains the original main entrance, a rectangular doorway with a classically designed frame. The fourth-story attic contains pairs of rectangular windows in each bay, surrounded by ornamented window frames. A parapet, containing a tablet with the words , runs above the center of the attic. Between the facade and the sidewalk is a planting bed surrounded by an iron railing; the space originally contained a sunken basement court.
The southern elevation on 58th Street and the northern elevation on 59th Street are both nineteen bays wide and differ only slightly from each other in design. The 58th Street facade has basement openings, and the tops of the arched openings contain transom panels made of buff brick. On the 59th Street facade, there are no basement openings, and the arched openings are topped by transom panels with glazed glass. On both facades, each bay is separated by pairs of rusticated brick pilasters, which contain simple bands placed at regular intervals. The fourth-story attic contains triplets of rectangular windows in each bay, surrounded by ornamented window frames, except in the outermost bays, where the windows are paired. There are portals on the easternmost bay of both facades, which were originally used by New York Central Railroad freight trains running along Eleventh Avenue; the rail line was later relocated into the West Side Line.; ; ; Several openings at the base contain roll-down metal gates.
Structural features The building is supported by a skeletal steel superstructure that weighs about . The floors and coal bunkers generally consist of I-beams, as well as plate girders similar to those used on plate girder bridges. The strength of the steelwork necessitated that the building use girders that would normally be used on bridges. The American Bridge Company manufactured the steel used in the superstructure. The floor girders are below the floor surface, and connecting beams are placed beneath the girders. The floor beams rest on "seats" that are riveted to the webs of the girders. The column girders vary in dimension based on the expected load for each column. The columns that support the cranes used in the operating house are supported by cantilevers.
The floors themselves were made of concrete arches, reinforced with expanded metals, with the floor slabs being a minimum of thick. The floor construction was to withstand test loads of on all flat portions of the roof, in the engine house, and in the boiler house. In the engine house, a secondary floor surface of slate slabs on brick partitions is placed atop the concrete arches. The engine room's main operating floor is on a mezzanine above the boiler house's floor. The roof over the operating house is supported by the crane-supporting columns, while the roof over the boiler room is supported by its own set of columns. The original chimneys were supported by platforms of I-beams and a system of plate girders deep.; ; ;
The foundation was constructed using various methods because of the uneven depth of the underlying bedrock, which ranged from about . Cast-iron bases were used to distribute the weight carried by the superstructure columns. Where the bedrock was near the bottoms of the cast-iron bases, a pad of concrete thick was poured under the bases. Some of the cast-iron bases rest on concrete foundation piers topped by granite. Massive granite bases were also poured into the foundation underneath where each of the twelve engines would be placed. The foundation also supports the 397 columns in the superstructure.
Equipment and operations
The IRT Powerhouse was similar in layout to larger power plants. The boiler room and the engine and generating room were separated by a brick partition wall. Galleries along the north wall of the generating room supported electrical switches and control board, and galleries along the south wall supported the auxiliary steam piping. The main northern gallery also housed equipment for a repair and machine shop. The walls of the boiler room were wainscoted on the lower portion and exposed brick on the upper portion. In case of a steam pipe failure in the boiler room, the brick wall would stop the steam from spreading to the generating room. Several traveling cranes were also installed throughout the powerhouse. When built, the IRT Powerhouse was intended to be the largest generating station on earth.
Boilers John van Vleck designed the boiler plant of the power house according to a unit plan that divided the plant into six independent functional sections, allowing for high operational flexibility.; ; ; ; ; Each unit contained two rows of six boilers, feeding two steam engines in the generating room. For each unit there were also two condensers, two boiler-feed pumps, two smoke-flue systems with economizers, and two complements of auxiliary apparatus. The twelve boilers were symmetrically arranged around one of the six chimneys.; ; ; ; Five of the boiler/engine units were identical; the sixth had a steam turbine plant, installed to power the generator for lighting the subway tunnels.; ; City mains provided the boiler feedwater.; ; The arrangement of the boilers on a single level, and placement of the economizers above the boilers, saved space. The layout permitted a higher, well-lit boiler room, which helped reduce temperature extremes and the risks caused by escaping steam.; ; ; The boiler room ceiling was high, providing space for ventilation.