The Denison Bridge is a heritage-listed footbridge over the Macquarie River in Bathurst, New South Wales, Australia. It is the fourth oldest metal truss bridge existing in Australia.
The bridge, completed in 1870, replaced an earlier bridge that was built in 1856 and destroyed in 1867 floods. It was designed by Gustavus Alphonse Morrell and built from 1869 to 1870 by P. N. Russell & Co. The bridge structure, except for the deck, is original and in excellent condition and for over 120 years the bridge carried the Great Western Highway over the Macquarie River.
In the early 1990s a realignment of the Great Western Highway resulted in the Evans Bridge replacing the Denison Bridge, with the latter converted to pedestrian traffic only. It was added to the New South Wales State Heritage Register on 1 August 2003, having earlier been listed on the now-defunct Register of the National Estate in 1978.
Historical details
Despite the growing importance of Bathurst as the principal urban centre over the Blue Mountains, the Macquarie River, which flows past the town on the Sydney side, was not bridged until 1856.
After years of local agitation, a long timber bridge with five laminated timber arches was started in 1855 and was opened on 1 January 1856 by the Governor, Sir William Denison. A bullock was roasted on a spit and 3000 people celebrated the new bridge, named after the Governor.
This was the last "official" bridge designed by the Colonial Architect's Department under its brief direction by architect and engineer, William Weaver (1828–68). It was supervised by his Clerk of Works, William Downey, during 1855.
Eleven days later another bridge over the Macquarie River a kilometre downstream was opened by a local entrepreneur, George Ranken (frequently quoted as Rankin): this bridge was known as the Eglinton Bridge or Rankin's Bridge.
The Denison Bridge was washed away by the great flood of 1867 and its debris also destroyed Rankin's Bridge, so after eleven years of having two bridges, Bathurst again found itself with only a ford or a ferry to cross the Macquarie. A narrow temporary wooden bridge was put across near the remains of the Denison Bridge later in 1867, but this was closed for safety reasons in June 1868. The government recognised that a permanent replacement was urgently needed. A new site was chosen 100 metres downstream from the first Denison Bridge and a realignment was made to the road approaches.
The new Denison Bridge was designed by Gustavus Alphonse Morrell, Assistant Engineer to the Department of Roads and foundation member of the Engineering Association of NSW. The bridge contract drawings bear Morrell's signature and that of William Christopher Bennett, Commissioner for Roads.
The bridge was constructed in 1869 to 1870 by the prominent engineering firm, P. N. Russell & Co at a cost of 18,818 pounds through the NSW Public Works Department. Most of the angle irons and bars were specially rolled for the job at P. N. Russell & Co's Pyrmont Rolling Mills and at Bathurst's two iron foundries of that time, including the nearby Denison Foundry. Only heavy iron plates and bars were imported. The cast-iron cylinders used in the piers were cast at P. N. Russell & Co's foundry in Sydney, mainly using pig-iron from the Fitzroy Iron Works.
Like the first bridge, the new one was opened by the Governor of the time, who was now the Earl of Belmore. Denison had left the colony in 1861 for Madras and then to retirement in England, where he died in 1871. But the new bridge, opened in June 1870, was the replacement of the Denison Bridge of 1856 and the name of Denison was retained.
Although incorporated in the original design, footways were never built as part of the bridge. A steel footbridge was erected in 1950, on the upstream side, by the Department of Main Roads.
In 1964-65: six piles were driven under the timber approach spans, 23 stringers were replaced, 6 round timber girders renewed, longitudinal sheeting replaced and deck bitumen sealed, timber decking replaced by high tensile bolts in three top chord joints, expansion bearings were repaired and one girder replaced. The deck was emulsion-sprayed and grit-covered. Further repairs in 1975-76 cost $11,377. A concrete deck was laid in 1981.
In use for over 120 years as a road bridge, its service life was interrupted only for a 9-day repair period in the 1960s. It was superseded by a prestressed concrete bridge upstream and closed to vehicular traffic in the early 1990s and adapted for use as a footbridge.