Building Description Atwater Kent Manufacturing Company, Philadelphia Pennsylvania

The former Atwater Kent Manufacturing Company facility consists of two expansive radio manufacturing buildings located in northwest Philadelphia on two parcels of land totaling 34 acres. The two parcels are located on Wissahickon Avenue, separated by U.S. Route 1, formerly known as Roosevelt Boulevard, and Abbottsford Avenue. The first building was erected in 1923 on the southwest side of Abbottsford Avenue, and is known as the South Plant. The second facility was built in 1928 on the northeast side of Abbottsford Avenue, and is known as the North Plant.

The former Atwater Kent Manufacturing Company, South Plant, is bounded by SEPTA, and Conrail tracks on the southwest, and Roberts Avenue and King Street on the southeast. The South Plant site presently consists of the original 1923 building, the southwest addition built in 1925, and a concrete block structure built in 1970. The South Plant is not the subject of this recordation, and has been previously described in great detail in permanent literature by Fogg (1925), Ashworth (1926), and Barucco (1992). Ashworth's article provides a table entitled "Summary Data on Atwater Kent Plant," which lists in the greatest detail all of the physical characteristics of the facility, including the type and manufacturer of all the principal fixtures and mechanical equipment of the building.

The former Atwater Kent Manufacturing Company, North Plant, consists of five buildings with parking areas on a 27-acre industrial parcel. The property fronts to the northeast on Wissahickon Avenue, and is bounded by Abbottsford Avenue to the southeast, the SEPTA railroad tracks to the southwest, and the National Guard Armory to the northwest.

The dominating feature of the North Plant property is the immense, three-level manufacturing building, rectangular in plan and covering approximately 11 acres. The manufacturing building itself has been historically referred to as the North Plant. Other buildings comprising the facility include the Powerhouse, built in 1927-28 along with the North Plant; a one-story brick and concrete gatehouse; a four-story concrete storehouse; a one-story concrete utility building; and a large air-conditioning condenser unit. With the exception of the Powerhouse, the remaining structures on the property post-date the period of historical significance of the property.

The North Plant measures 911'-5" by 515'-5", with its long axis paralleling Wissahickon Avenue, and consists of a main level, a basement, and a sub-basement. The building is constructed on a slope which drops nearly 40' between Wissahickon Avenue and the railroad tracks. As a result, the front elevation of the building is 28' in height, while the rear elevation is 68' in height. The foundation and structural frame of the building are reinforced concrete, and the exterior walls are load-bearing brick. The columns are spaced 40' on center, and carry a proprietary saw-tooth roof system known as the "Super-Span Saw-Tooth" roof, designed by The Ballinger Company of Philadelphia, the building's architects. The 48 triangular roof sections each consist of an integral steel truss, north-facing glazing panels, and south-facing reinforced gypsum roof panels. Due to the recent failure and collapse of sections of the gypsum roof panels, the entire roof has been enclosed and supported from below with plywood and a wooden structural system. To reduce heat loss and water infiltration, the skylights were encapsulated with a fiberglass and polymer resin coating. Design details and the history of the development of the saw-tooth roof structure are further discussed below.

The brick exterior walls are organized into a system of bays flanked by shallow brick pilasters. The building is capped with a brick parapet ornamented with diamond-patterned frieze panels. Terra cotta is used for window sills, coping, and decorative belt-courses and downspout openings. The building's original metal-frame industrial windows have all been replaced with tripled 1/1 aluminum-frame insulated-glass replacement windows. Four sets of windows are located in each bay defined by the pilasters, except in the corner bays, which contain two sets. Other window openings have been enclosed with a variety of materials, including wood panels, brick, and glass block.

The principal entrances are located on the northeast side, and consist of four-bay pedestrian doors on the main and basement levels. The interior of the building has been extensively remodeled over the years with the addition of concrete block and gypsum board partition walls, various floor coverings, and escalators. The "Super-Span Saw-Tooth" roof trusses and skylights are completely obscured from view with a suspended ceiling. Originally, the ceiling was completely open to the main manufacturing floor. Unit heaters, a relatively new concept at the time, were suspended from the roof trusses. The heaters consisted of hot water radiators supplemented with electric fans to circulate the air. The skylight sections of the roof were of the movable type, operated by rods running down the columns, and provided ventilation on warm days.

Sections of the original maple strip flooring on the main level are exposed in parts of the office areas. The interior of the building was originally planned as single open spaces on each level, interrupted only by restrooms, stairways, and elevator housings. Lower levels, which were used for storage and shipping of the finished products, are largely intact as originally designed, with open concrete columns, floors, and walls. Hanging fluorescent lighting fixtures and vinyl flooring tiles have been added.

The Powerhouse is a flat-roofed, rectangular-plan, brick industrial-type building, approximately 63' wide by 202' long. The Powerhouse was built to shelter two coal-fired boilers which provide steam heat to the main manufacturing building at the North Plant. The building is located on the western edge of the property, between the main manufacturing building and the tracks of the former Pennsylvania Railroad. The building is of riveted steel frame construction with brick enclosure walls, and consists of three sections arranged linearly along the northwestsoutheast axis of the building. The main section housing the boiler room occupies the north half of the building, followed by two smaller sections which house transformers, switching equipment, workshops, storerooms, and a locker room. Industrial-type metal-frame windows are stacked in tall vertical openings to form three bays across the ends of the building and twelve bays along its length. The building retains all of its original solid-section steel windows, which are divided into 14" x 20" lights with horizontally pivoting ventilators of either, four or eight lights. The building retains two of its original exterior doors. They are large paired wood swinging doors with nine lights over two recessed panels.

The boiler room section visually dominates the building, due to its size and its distinctive exterior architectural detailing on the upper third of the walls. The boiler room section is six. bays in length and more than twice the height of the adjoining sections, measuring 63' wide, 118' long, and 87' high. A stair and elevator tower located at the southwest comer rises an additional 16' above the roof, and provides access to five levels of steel catwalks within the open boiler room. The upper portions of the building's facades feature recessed brick panels, carrying smaller windows than the corresponding bays below, flanked by corbeled brick pilasters surmounted by decorative terra cotta capitals in the form of lancet windows with steep gable hoods. Decorative brick wall panels are located beneath the top windows of the tower and main block and feature diagonally patterned brickwork.

The three sections of the building are separated by interior brick fire walls and sliding steel fire doors which automatically close by gravity in the event of fire. Door openings in the interior brick walls are headed with brick rowlock arches. The west facade of the two smaller sections of the building features a high brick parapet which conceals the differing roof elevations. The parapet is decorated with corbeling, which outlines panels corresponding to the window openings below. The parapet of the entire building is capped with terra cotta tiles and scuppers.