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C. Building the Bridge

The Allegheny County Commissioners' decision to build a bridge across such a commercially and strategically important navigable waterway in 1928 involved more than just Henry Tranter's exhortations and a set of blueprints prepared in the offices of the County Department of Public Works. Before securing a necessary charter for the bridge from the U. S. House and Senate, replete with the signature of President Herbert Hoover, the bridge plans had to first receive approval from the Army Corps of Engineers and the Secretary of War. Other less-esteemed agencies participated in the bridge approval process as well. For example, the Pennsylvania Water and Power Resources Board gave its assent, as did the county and city planning commissions, the City Art Commission, the Grand Jury, and the Allegheny County Court of Quarter Sessions (White and Von Benewitz 1928).

Therefore, the county commissioners' decision in 1928 to include the West End-North Side Bridge in their "People's Bond Issue" represented only a first step. It was not until November 1928 that County Commissioners Joseph Armstrong, E. V. Babcock, and Charles McGovern adopted a resolution directing the location, construction, and maintenance of the West End-North Side Bridge, "deeming it expedient for the purpose of accommodating public travel." The commissioners approved the bridge cost at $3,540,000 and, on December 9, 1929, the Allegheny Court of Quarter Sessions, having been assured that the notice of the bridge's imminent construction had been duly advertised in city newspapers, approved the bridge plan and ordered its construction. It was in September 1930 that the Allegheny County Bureau of Bridges, aided by the County Bureau of Architecture, accepted the bridge design (Allegheny County Controller's Annual Report, December 31, 1930; Allegheny County Bridge Docket, November 8, 1929; December 9, 1929; December 20, 1929).

Described as a "tied-arch" bridge, the West End-North Side span was designed by the Allegheny County Department of Public Works, Bureau of Bridges. Historically and technically, the bridge was the second long-span tied-arch bridge to be constructed in America. The first was the Tacony-Palmyra Bridge that spans the Delaware River in eastern Pennsylvania. The West End-North Side Bridge design features pre-stressed wire-rope hangers, a principle which disguises the massive weight of the bridge. Like the "string of a bow," the hangers put the stress of the bottom chord in tension with the main arch. It was also the first bridge to employ high strength silicon steel (U. S. Department of Interior, 1967).

Since this study focuses on the bridge's impact on the Chateau area on North Side, another aspect of the bridge's design warrants greater attention. In order to articulate traffic patterns efficiently between North Side and the Saw Mill Run Boulevard and the Lincoln Highway on West End, the bridge design raised Main and Steuben streets on West End to the upper bridge level, tying the bridge on grade to Carson Street. Connecting the high level bridge to the high grades on the southern and northern ends necessitated high level approaches. Therefore, on the southern end, three Warren half-through (pony) truss bridges approach the bridge from Carson Street. On the northern side, four Warren (pony) trues bridges approach the bridge from Western Avenue (Allegheny County Controller's Annual Report, December 31, 1939:252). While the truss bridge approach on the southern end crossed only the railroad tracks of the Pittsburgh and Lake Erie Railroad, on the northern side, the bridge approach cut through established industrial and residential property. Its route included the land adjoining Crucible Steel Company and land occupied by Rodgers Sand Company and the Stroh Steel Hardening Process (Allegheny County Department of Public Works, Bureau of Bridges, November 1929).

The July 17, 1984, "Final Environmental Impact Statement" (U.S. DOT) found that removal of the pony trusses would not affect the National Register of Historic Places qualities of the West End-North Side Bridge. However, it is clear that the relationship of the bridge to the history of improving the efficiency of Pittsburgh's traffic articulation, especially the engineering of street grades to conform with the bridge height, made the truss bridge approaches an integral part of the design. Viewed from a distance, the two Warren truss bridge approaches to the tied-arch main span create a somewhat symmetrical balance (U.S. DOT 1984:118).

On February 6, 1930, the county awarded the contract for the bridge construction of the giant stone substructure to the Foundation Company of New York. Eight months later, the county gave the contract for the superstructure to the American Bridge Company. While portions of the southern approach opened in advance of the bridge completion, the entire project opened officially with a ribbon-cutting ceremony on December 2, 1932, a full five months before the contracted date of completion (Allegheny County Controller's Annual Report, December 31, 1952; U. S. DOT 1984:118-125).

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