American Bridges of the NSW North Coast Railway

Abstract

The North Coast Railway of New South Wales from Maitland to South Grafton, 1911–1923, was the first trunk line of the NSW railway network built to uniform standards for track and structures, particularly the underbridges. Unlike the earlier trunk lines, north, west and south of Sydney, which were progressively upgraded to main line standards, the North Coast Railway was designed and built to main line standards to ensure reliable long-term, cost-effective performance compatible with the projected extension of the standard gauge railway to Brisbane. Importantly, all the steel trusses, steel girders and transom-topped timber spans were based on American bridge technology, including the American Railway Engineering Association Design Code. The original steel bridges continue in service (the timber bridges having been replaced by welded steel girders) and now constitute a family of historical bridges of high heritage signifi cance. This paper summarises the background to the change from British bridges to the new designs by eminent bridge engineer J. W. Roberts, culminating in closing the gap across the Clarence River in 1932 with an American double-deck bascule bridge.