page_title: Clackline Bridge
section_title: Design and construction
hierarchical_section_title: Clackline Bridge / History / Design and construction
caption_attribution_description: English: A plan from 1935 showing the location of the then-new overhead bridge over the gully at Clackline, Western Australia, to be opened by the Acting-Minister for Works (Mr. H. Millington). A new portion of the main road between Perth and Northam was constructed to serve the bridge and avoid a dangerous deviation and two railway crossings.
context_page_description: Clackline Bridge is a road bridge in Clackline, Western Australia, 77 kilometres east of Perth in the Shire of Northam, that carried the Great Eastern Highway until 2008. It is the only bridge in Western Australia to have spanned both a waterway and railway, the Clackline Brook and the former Eastern Railway alignment. The mainly timber bridge has a unique curved and sloped design, due to the difficult topography and the route of the former railway. The bridge was designed in 1934 to replace two dangerous rail crossings and a rudimentary water crossing. Construction began in January 1935, and was completed relatively quickly, with the opening ceremony held in August 1935. The bridge has undergone various improvement and maintenance works since then, including widening by three metres in 1959–60, but remained a safety hazard, with increasing severity and numbers of accidents through the 1970s and 1980s. Planning for a highway bypass of Clackline and the Clackline Bridge began in the 1990s, and it was constructed between January 2007 and February 2008.
context_section_description: Main Roads engineer Ernest Godfrey completed a design for the Clackline Deviation, a single bridge over the waterway and railway, in August 1934. Godfrey was the first bridge engineer for Main Roads, and is credited with introducing concrete and steel bridges into Western Australia; however, for Clackline Bridge, he proposed using timber – the standard material for the preceding hundred years – with steel construction only for the longer span over the railway. He also suggested that a footpath be included on the bridge, so that schoolchildren and other pedestrians would have a safer railway crossing. The cost was estimated at £8500, plus an additional £700 for the footpath. The initial design was moved 10 feet (3.0 m) south, to satisfy the Railways Department's requirement that the route not be too close to the Toodyay railway line (a spur line off the Eastern Railway) that ran parallel to the highway. This shift increased the curve radius, but required "the destruction of some well developed pine trees inside the old boundary fence of the [Clackline School] playground".
  Construction was undertaken by Main Roads Department day labourers, starting in January 1935, as part of an unemployment relief works program. The Western Australian Government Railways (WAGR) was involved in various aspects of the project – some railway land acquisition was required, and WAGR supplied and supervised a five-ton crane, used to erect the railway span girders. The bridge was completed less than one year after construction began, which would later be described as "a considerable achievement of the management and workforce for such a complex structure". Clackline Bridge was opened on 30 August 1935 by Acting Minister for Works H. Millington, having cost £9000. The first vehicle to cross the bridge was Millington's car, carrying himself and Albert Hawke on the front bumper, and a small boy who decided to take a ride on the rear bumper. Afterwards, there was an official lunchtime party in Northam, hosted by the Northam Roads Board.
caption: Clackline Bridge allowed the main road to avoid two railway crossings and dangerous curves, as shown in this map from 1935.
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