Macquarie River railway bridge, Dubbo

The Dubbo rail bridge over Macquarie River is a heritage-listed railway bridge on the Main Western line across the Macquarie River, located west of the Dubbo central business district in the Dubbo Regional Council local government area of New South Wales, Australia. It was designed by John Whitton as the Engineer-in-Chief for the New South Wales Government Railways. The bridge was built during 1884 by Benjamin Barnes, with ironwork by Cochrane & Co, Middlesborough [sic], England. The railway bridge is also known as the Dubbo Lattice Railway Bridge. The property is owned by RailCorp, an agency of the Government of New South Wales. The bridge was added to the New South Wales State Heritage Register on 2 April 1999.

The bridge is sited 462.762 km from Sydney Central station.

History
During the 20-year period 1873-1893 there was a massive programme of public works in New South Wales, particularly in expanding the road and rail networks. It was a boom period that ended with a severe economic depression.

Despite the boom conditions, the respective Chief Engineers, for Roads, William C Bennett, and for Railways, John Whitton, were constrained to economise by using as much local material as possible, consequently an enormous amount of hardwood timber was used for bridgeworks, mostly timber beam and timber truss bridges. However, there were many major rivers to be crossed, requiring long span bridges, for which no form of timber bridge was suitable. These large bridges had to be metal and supplied from England, a very expensive import cost to the successive colonial governments.

Both Chief Engineers were British so they chose the widely used wrought iron lattice truss bridge in the half-through form. Twelve of these were built for the railways and 24 for roads. These two sets of iron lattice bridges are the most significant group of bridges of the colonial period. A high percentage are extant and still in use, 11 on railways and 18 on roads. The current railway lattice bridges are:
 * 1876Bathurst Rail Bridge over Macquarie River
 * 1881Murrumbidgee River at Wagga Wagga
 * 1881Macquarie River at Wellington
 * 1882Peel River at Tamworth
 * 1882MacDonald River at Woolbrook
 * 1884Rail Bridge over Murray River, Albury-Wodonga
 * 1884Macquarie River at Dubbo
 * 1885Murrumbidgee River at Narrandera
 * 1887Lachlan River at Cowra.

Two former railway lattice bridges (1885 Georges River at Como and 1886 Parramatta River at Meadowbank) were converted for use by pedestrian/cycle ways.

The 1871 lattice railway bridge over the Hunter River at Aberdeen was replaced by steel girders and demolished.

Description
A 3-span continuous iron lattice bridge. The spans are 159 ft to centres of piers and the lattice work has four triangulations. The piers of pairs of cast iron cylinders (supplied by Cochrane & Co, England). The bridge has wrought iron plate web girders at each end of the lattice bridge.

Condition
As at 10 August 2006, the physical condition was good.

Heritage listing
As at 10 August 2006, the bridge at the end of the yard is one of John Whitton's single track lattice bridges which were typical of the period of construction and is of high significance to the state system. The viaduct in leading to the actual bridge was originally timber but has been replaced by PWG steel.

This bridge is a member of the most significant group of colonial bridges in New South Wales. Collectively, as items of railway infrastructure, they contributed significantly to the history and development of New South Wales. Each bridge is an imposing structure at its site. In terms of contemporary bridge technology the wrought iron lattice bridge was among the best for major bridgeworks.

Dubbo rail bridge over Macquarie River was listed on the New South Wales State Heritage Register on 2 April 1999 having satisfied the following criteria.

The place is important in demonstrating the course, or pattern, of cultural or natural history in New South Wales.

Twelve wrought iron lattice railway bridges were built in New South Wales during the boom period for railway construction 1871-1887, starting at Aberdeen and ending at Cowra. Nine of the survivors are owned and managed by the Rail Access Corporation.

The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

All nine iron lattice railway bridges are imposing structures.

The place has a strong or special association with a particular community or cultural group in New South Wales for social, cultural or spiritual reasons.

Every iron lattice railway bridge crossed a major river which made it possible for the railway extension to develop the districts reached, socially and commercially.

The place has potential to yield information that will contribute to an understanding of the cultural or natural history of New South Wales.

The iron lattice bridge was a technically sound structure for the bridge technology of the late colonial period. Its strength and durability have shown it to have been a very cost-effective form of bridge.

The place is important in demonstrating the principal characteristics of a class of cultural or natural places/environments in New South Wales.

Collectively, the iron lattice railway bridges represent a significant class of bridge structure.