Ashburton River Road Bridge

Values

the place demonstrates rarity and technical achievement as an early attempt at a concrete bridge and demonstrates a number of technical innovations new to the state at the time of construction;

the place has historical associations with the development of Main Roads as a state department, particularly the transition between Main Roads Board and Main Roads Department 1926-1930;

the place is associated with the public works instituted by the Western Australian government during the Depression to provide relief to the unemployed;

the place is associated with the development of the Ashburton area in the early 20th Century; and,

The place was designed by E Godfrey, a pioneering bridge designer who worked for Main Roads 1928-1957.

Physical Description

The place is a composite steel and concrete traffic bridge over the Ashburton River with steel footings and joists. The bridge encompasses four spans for a total length of 74 m in length and 4 m in width, with a maximum height of 14 m.

The bridge rests atop a number of hollow steel tube piers, set into reinforced concrete, sprayed with bronze as a form of waterproofing. The steel joists supporting the decking were attached directly to the tops of the hollow piers, without the need for capping. The original deck was composed of jarrah, although the current surface is bitumen.

The bridge is still in use, the condition of the bridge is described as good.

History

The Interwar period in the East Pilbara was characterised by a slow growth, with the regional economy based upon mining and pastoralism. Transport methods included rail, shipping, the introduction of aeroplanes in 1921 and the continued use of camels. Cars were introduced in 1913 but faced problems due to the lack of parts and harsh local environment. A source of frustration for locals was the Fortescue River crossing near Roy Hill station, which was impassable during flooding and unsuited to heavy vehicles. In particular, the mail was frequently delayed during the flood season.

A bridge over the Ashburton River was first proposed in 1910 in relation to the proposed upgrades of the Onslow jetty, which settlers had hoped to upgrade into shipping facilities capable of servicing the lead mines. Unfortunately, the cost of both an upgraded shipping facility and a bridge over the Ashburton River was considered too costly, and the matter was still being debated in 1920. It was not until 1925 that a site for a bridge was selected.

The Main Roads Board was established in 1926, taking over some of the responsibilities of the Public Works Department, including bridge construction. The board was re-established as the Main Roads Department in 1930.

The economic policies of the Western Australian government during the 1920s can be described as broadly expansionist, in particular agricultural and pastoral expansion, which suffered severe contraction due to droughts and the effects of the Great Depression. At the end of the 1920s and the during the early 1930s, the government responded in a number of ways, including stimulating the building market and investing in the expansion of industrial development, in particular the mining industry and capital works projects such as dams, sewerage, clearing and roads. The development of roads in particular became important as families to the capital for work and created rapid urbanisation. Main Roads was an active part of this response, providing short-term work for unemployed on a variety of infrastructure projects, even while struggling to cut costs and staff within their own structure. These works included road works and bridgeworks, with a focus on the southwest of the state. The northwest received less attention, the unemployment focused on the worst roads and river crossings.

The specific project details for the Ashburton River Bridge are not available, as the Main Roads file on the bridge (MR38-29) cannot be located. However, a notation on the cover of a related file at the Stat Records Office indicates that the road works were part of a larger unemployment relief project. As such, it is possible that Ashburton River Road Bridge was part of this unemployment project although more research will be needed to confirm this.

Ernie Godfrey was responsible for final design of the Ashburton River Road Bridge. Godfrey arrived in Western Australia from Victoria in 1928, to take charge of the Bridge Section of the Main Roads Board. Active and well-respected, Godfrey was a key designer on a number of large bridge projects until his retirement in 1957 and later acted as a consultant for the design and construction of the Narrows Bridge from 1958-1959.

Tenders were called for the construction of the bridge in 1927 at a cost of £6500. Despite this work on the bridge was not immediately carried out, in part due to the need for materials to be made in Perth and shipped to Onslow, as well as painstaking studies on the physical properties of the sand and stone. The Resident Engineer for the Northwest was at this time C Field, assisted by F Brennan, who carried out the boring operations at the proposed bridge site in June 1928. By January 1929 the bridge design was announced, this time at a cost of £10,000. Despite the announcement declaring that work would commence in April, the tender was not accepted until August that year, a tender of 15303 accepted by £Atkins and Gorham. At this time the bridge design was described as:

The length of the Ashburton River bridge overall will be 243ft., consisting of five intermediate spans of 40ft. and two end spans of 20ft. The foundation to piers will consist of reinforced concrete piles driven in two groups of three and surrounded with concrete. Concrete piles will be driven at the abutments which will be of mass concrete. The piers will consist of two steel cylinders with steel girder cross bracing, electric-arc-welded to the sides of the cylinders. The whole of the piers will be fabricated in Perth at the wonks of the manufacturers, after which the piers will be metal sprayed as a rust preventive. The maximum weight of any one pier will be about seven tons. Each pier will carry two broad flanged beam girders, supporting intermediate steel girders carrying the jarrah deck floor.

The apparent lack of progress on the bridge was cruised at the time as being deliberately impeded to have the completion coincide with upcoming government elections.

Preliminary work on the bridge proceeded sluggishly, the head of construction, J Head, still preparing for construction in February 1930. By March Godfrey himself visited the site to inspect the progress which was described as “unfortunately being somewhat retarded by the lack of certain equipment which is not expected to arrive for some time.” Work did not recommence until August 1930, when the necessary material to complete the bridge arrived from Perth. Work was finally completed in May 1932, the bridge opened by R Forrest with Godfrey and the construction contractors present. It was noted at the opening that the bridge was the only one of its kind in Australia. The use of sprayed bronze in particular was a form of waterproofing was unique at this early stage, and was not a common practise until 25 years later. Godfrey himself remarked on the bridge in 1960:

The bridge represents a pioneering endeavour in the area near Onslow on the North West Coast where facilities and materials for construction were limited.

The steelwork on the bridge was recondition in 1963 and repairs were made to the deck in 1965. The jarrah deck was replaced in 1992 with a concrete overlay, and the timber handrails were replaced with steel.

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This information is provided voluntarily as a public service. The information provided is made available in good faith and is derived from sources believed to be reliable and accurate. However, the information is provided solely on the basis that readers will be responsible for making their own assessment of the matters discussed herein and are advised to verify all relevant representations, statements and information.