page_title: Cantilever bridge
section_title: Construction methods
hierarchical_section_title: Cantilever bridge / Construction methods
caption_attribution_description: English: The old eastern span of the San Francisco-Oakland Bay Bridge is deconstructed in the reverse order of its construction , image taken 2014-08-23
context_page_description: A cantilever bridge is a bridge built using cantilevers, structures that project horizontally into space, supported on only one end. For small footbridges, the cantilevers may be simple beams; however, large cantilever bridges designed to handle road or rail traffic use trusses built from structural steel, or box girders built from prestressed concrete. The steel truss cantilever bridge was a major engineering breakthrough when first put into practice, as it can span distances of over 1,500 feet, and can be more easily constructed at difficult crossings by virtue of using little or no falsework.
context_section_description: Some steel arch bridges (such as the Navajo Bridge) are built using pure cantilever spans from each side, with neither falsework below nor temporary supporting towers and cables above. These are then joined with a pin, usually after forcing the union point apart, and when jacks are removed and the bridge decking is added the bridge becomes a truss arch bridge. Such unsupported construction is only possible where appropriate rock is available to support the tension in the upper chord of the span during construction, usually limiting this method to the spanning of narrow canyons.
caption: The old eastern span of the San Francisco–Oakland Bay Bridge, pictured in August 2014, is deconstructed in nearly the reverse order of its construction. Similar temporary supports were used under each anchor arm during the bridge's construction.
exif: {}