Gustav Lindenthal - Construction Techniques

Construction Techniques

During the time Lindenthal practiced engineering, the railroad industry was expanding and replacing many wooden-truss bridges with stronger ones capable of handling the heavier locomotive loads. In order to accommodate these heavier trains, different construction materials were being utilized. The materials being considered by engineers like Lindenthal were reinforced concrete, cable, and steel. Steel and reinforced concrete were two main materials used in the truss bridges Gustav Lindenthal designed. The use of reinforced concrete was a relative new idea in bridge construction, with its first use in 1889.

The design of the Hell Gate Bridge required a different approach to bridge construction. Nearly all major members of Hell Gate are composed of smaller trusses. The erection of the Hell Gate was carried through without the assistance of any false work, or work that was not part of the actual bridge. This was accomplished by building the two halves of the arch simultaneously from each tower. The steel work was supported with the use of cables during construction to carry the load of the arches until they finally met at the center of the span.

In another instance, a bridge needed to be constructed over the Monongahela River, after the ferry, which was used for many years beforehand, became outdated. The first bridge, designed by John Roebling, continuously swayed and deflected, as well as being "shaky and loose." Lindenthal was then given an opportunity to design a replacement, the Smithfield Street Bridge in Pittsburgh. This bridge, completed in 1883 using the structural form of a lenticular truss, could withstand higher stresses, as well as using resources that made it more economical (Approximately $23,000 was saved simply by using these materials). "Lindenthal's use of steel instead of iron wherever possible was based upon economy as much as anything."