Manhattan Bridge ca. 1936

The Manhattan Bridge, the first suspension bridge to use flexible steel towers, was built concurrently with the Queensboro Bridge. Gustav Lindenthal's technical innovations for the Manhattan Bridge, and his insistence on incorporating aesthetic elements into the design, were disapproved by Tammany Hall politicians and other powerful figures: Such political resistance prevented Lindenthal from acquiring funds or political backing for his design and eventually he and Hornbostel were replaced by designer Leon Moisseiff and the architectural firm Carrere and Hastings, respectively. Moisseiff altered Lindenthal's plan by substituting conventional wound steel cables for nickel-steel chains and by reducing the proposed size of the structure's tall stiffening trusses. It has been speculated that the real cause of Tammany opposition to Lindenthal's design was that it called for nickel-steel and therefore failed to provide business to the Roebling Company, the only one producing steel cables. Various explanations have been offered was to why the completed bridge could just barely support the necessary weight: that Moisseiff neglected to undertake certain critical calculations (he later designed the Tacoma-Narrows Bridge, Tacoma, Washington, which collapsed shortly after its 1940 opening, taking his career with it) or that inferior materials, inadequate to withstand predicted traffic-load pressures, were used. Whatever the cause, the Manhattan is the most troublesome of New York City's suspension bridge, although it has the greatest traffic capacity of the four East River bridges.