Atwater Kent Powerhouse (5000 Wissahickon Avenue), Philadelphia, PA

The Powerhouse is a long rectangular brick industrial building, approximately 63' wide by 202' long, and constructed of a riveted steel frame with brick infill walls. From the exterior, it is visually divided into two primary masses herein referred to as the western and eastern blocks. Three coal-fired boilers originally occupied the tall western block and provided steam heat to the North and South Plant manufacturing buildings. The eastern block of the building is less than half the height of the western block; it houses the transformers, switchgear, workshops, storerooms and the employee locker room. The Powerhouse is located directly behind the North Plant manufacturing building near the southeastern corner of the property, adjacent to the former Pennsylvania Railroad tracks. The building is organized along the east-west axis and separated by two major brick partitions into three rooms as follows: the boiler room on the west end, the pump room in the center and the transformer room on the east end. From the exterior, the boiler room occupies all of the taller western mass and the pump room and transformer room are massed together to form the shorter eastern block. A centrally located stair tower, on the south elevation, projects its penthouse above the parapet of the taller western mass. The western block was designed to house boiler equipment. The original coal-fired boilers required extensive vertical space for the three-story housings, stacks, fans and coal supply. The boilers were located in alternating structural bays (one bay wide and two bays deep) in the northern two-thirds of the first floor of the western block. The dark brown exterior brick elevations are punctuated with white terra cotta panels, parapet copings and sills. The flat built-up roofs are concealed by brick parapets on all elevations. Painted steel sash industrial windows (mostly original) are stacked to define three bays along the east and west ends and twelve bays along the north and south faces. Almost all of the windows contain at least one operable section. In the taller windows the pivoting sections are ganged together to open from an interior accessed cranking system which no longer functions. Massive original paired wood frame doors remain on the south elevation, however; the primary building access is now from the east and west ends. A service bridge extends from the North Plant's loading dock to a rolling door on the eastern end of the Powerhouse's north elevation. The articulation of the western block works to emphasize verticality and a sense of strength and control. There is no question for the viewer where the heart of the operation was located. The eastern block was designed so much less heroically that it appears at first to be a later addition, however; it was designed and built at the same time as the western block. From the south elevation, the eastern block appears to be a continuous two-story space. From the north elevation moving eastward, the reduction in ceiling height is readily apparent. The center room on the first floor was the original pump room and it still contains a mezzanine level. The extreme eastern room on the first floor is the one-story transformer area. However, an extremely high parapet wall on the south and east sides of the eastern block unify the elevations and make the two rooms read as one block. Above the tall windows of the western block's south elevation are three upper levels, accentuated by brick pilasters attached to the exterior walls. At the top of the pilasters are white terra cotta panels which taper at the top to the face of the brick. The panels feature a tall arched niche with a hood-mould which, although similar to the main building's terra cotta panels, are not duplicated from the main building. The white panels are separated by windows which illuminated the top of the original coal bunker. Below these windows are solid panels with brick marquetry insets. This windowless level corresponded to the upper body of the coal bunker, which was directly inside the exterior wall. The white terra cotta panels appear on all the elevations of the western block however; only the south elevation and the central stair tower have the marquetry insets. This gives slightly more importance to the south elevation, which would have been the original "front" of the building, when as a powerhouse it received incoming services such as the delivery of coal and removal of waste ash from this side. The exterior architectural detail of the eastern block is much more simple than that found on the western block and demonstrates much less visual movement. It consists of rectangles defined by alternating projecting bricks in rows to form a border around a plain running bond field. A row of bricks at the base of the rectangle projects to form a sill which is held up visually by brackets of projecting brick ends. A notched white terra cotta parapet coping is underscored by a corresponding brick soldier course which uses diagonally-cut bricks to produce mitered corners at the notch. The three-story steel sash industrial windows of the south, west and north elevations reflected the scale of the original boilers and provided daylight to the mezzanines which serviced the operations. Although the catwalks in the mezzanines were extensively modified when the original boilers were removed (date unknown), several incomplete levels remain. Some of the catwalks and the fan gallery may be accessed from the central stair tower. Although shown on the original design drawings, the northeast fire exit stair may have been a late addition to the building. It was added as a distinct mass to the Powerhouse and left void of exterior details. Its purpose was to provide an additional exit from the North Plant; however, the exposed bridge and railings linking the tower to the North Plant were removed in the early 1990s. Presently, only a few utility lines span the former bridge location. The upper four levels of the stair tower have been permanently closed. The loading dock on the east side of the Powerhouse is connected to the North Plant's south loading dock and it provides covered pedestrian access between the buildings. However, with its present fencing, the dock cannot receive trailer deliveries. To the south of the Powerhouse, a narrow grassy area is surrounded by continuous curbing on three sides and the building on the fourth; it receives runoff from the paved parking area to the west. The east end of this lawn contains two sub-grade 25,000 gallon oil tanks. Near the center of the lawn is an abandoned electrical platform tower and a single visible surface drain (which was clogged). Along the curb edge of the eastern lawn are partially buried railroad tracks. It is likely that the concrete walls of the original sub-grade coal hopper are still in place near the center of the lawn (adjacent to the clogged drain). The first floor and full basement level are comprised of painted concrete floors and ceilings. The walls are painted brick; however, the pump room and transformer rooms on the first floor have a glazed brick wainscotting.

The Powerhouse is currently under consideration for listing onto the National Register of Historic Places under Criterion A, because of its properties which are "associated with events that have made a significant contribution to the broad patterns of American history."

The Powerhouse was completed in 1929 and provided coal-fired steam heating to both the North and South Plants of the Atwater Kent Manufacturing Company. Coal was the primary source of fuel for steam generation at the Powerhouse when it was completed. At an unknown date in the building's history, the fuel source was converted to oil. When the South Plant was sold off, the Powerhouse was used to provide heat strictly for the North Plant. At present, the North Plant is scheduled for demolition upon completion of a new office building. In accordance with a Memorandum of Agreement between the Pennsylvania State Historic Preservation Office, the United States General Services Administration (current owner of the complex) and the Advisory Council on Historic Preservation, the Powerhouse will remain architecturally intact to serve as a reminder of the facility that once covered 34 acres, employed over 12,000 people and produced over 6,000 radios per day during its brief life.

The Atwater Kent Manufacturing Company was once the largest manufacturer of radios in the world and its founder, Arthur Atwater Kent, was a prominent force in Philadelphia's industrial development. Kent was a prolific inventor of electrical components and systems who obtained 93 patents over his career. He relocated the Kent Electric Manufacturing Company (formed in 1895) from Massachusetts to Philadelphia in 1902 and diversified from the production of fans and motors into the production of electrical components for automobiles. In 1905, he invented the Unisparker which combined ignition points, condenser, centrifugal advance mechanism, and distributor in one unit. This system was used in automobiles until the recent development of fully electronic systems. In 1921, Kent became fascinated with radios and quickly moved from the manufacture of components into the manufacture of complete radios. Kent brought numerous firsts to the radio marketplace, including radios operating on alternating current. He popularized one-dial tuning and the sheet metal cabinet, which further reduced production costs and expanded the low-end market.

In 1923, Kent began construction of a new manufacturing facility in northwest Philadelphia. The South Plant was constructed first and was followed by the North Plant in 1928. Construction of the Powerhouse followed immediately after the North Plant. The North and South Plants were connected by a pedestrian and vehicular bridge over Abbottsford Avenue (which separated them); the bridge was demolished with the construction of U.S. Route 1 in the late 1940s.

During the period of peak production at the North and South Plants, Kent spent millions of dollars on major advertising campaigns in print and on the radio. In 1925, he sponsored the popular "Atwater Kent Hour" radio program which featured leading musical talents of the day. Kent strongly believed in advertising and it kept him in position as the market leader at least until the Depression. Kent dissolved the company and auctioned off the equipment in 1936. In 1941, the U.S. Signal Corps acquired the North Plant for its Eastern Depot. After World War II, the property remained with the U.S. Government. It became the home of the Veterans Administration in 1949 and later housed The National Archives (1950s) and The U.S. Treasury (1960s).

Although the Powerhouse complies in its basic form to the functional requirements of a coal-burning power plant, it adopted architectural motifs and materials similar to those of the main plant. The Powerhouse does not contain the patented "Super-Span" roof system found in the North Plant; however, it is a largely unaltered example of an industrial building prototype, separated out from the primary buildings and given it its own distinct form as a power provider. In modern buildings, the power source is invisible. However, with the demolition of the North Plant at the Atwater Kent facility, the Powerhouse hopes to be seen as an architectural pictograph of the immense impact of radio.

Description Architect
1929 Original Construction The Ballinger Company
Last Reviewed: 2021-08-24