Denison Bridge

Denison Bridge
Coordinates
Carries	Motor vehicles, Pedestrians,
Crosses	Macquarie River
Locale	Bathurst, New South Wales
Heritage status	Registered
Preceded by	Bridge (1856-1867)
Characteristics
Design	Truss bridge
Material	Steel
Total length	142.7 metres (468 ft)
Width	6.1 metres (20 ft)
Longest span	34.5 metres (113 ft)
Number of spans	9 (three at 6.7m, 34m, 34.5m, 34m, three at 6.7m)
History
Construction end	1870

The Denison Bridge is a heritage-listed road bridge 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. The bridge structure, except for the deck, is original and in excellent condition.

The Denison Bridge was registered on the Register of the National Estate in 1978.

Historical details

File:Denison Bridge, Bathurst.jpg

Denison Bridge, Bathurst

Denison bridge was an advanced design for its period and a major engineering achievement, it was the maximum span possible with a wrought iron truss span structure. Three colonial engineers are associated with the bridge; William Bennett (Commissioner and Engineer for Roads), Gustavus Alphonse Morrell (Assistant Engineer and designer) and Peter Nicol Russell (P N Russell & Co). It is the second oldest metal truss bridge in New South Wales after the Prince Albert bridge at Gundagai.

Engineering details

The new bridge was designed on the new American Pratt truss type construction style.

First Denison Bridge

The first Denison Bridge was a three span laminated bow-string arch British type bridge commenced in January 1855 and completed the following year. The first bridge only lasted 11 years after it was destroyed by floods in 1867. The following article of the time provides great detail of the construction and the features of the first Denison Bridge:

The bridge is built of wood, strengthened in parts by iron rods; it has five arches, so to speak, built upon the suspension principle. The arches at either end are small, having a span of about fifty feet, while, the remaining space is divided between the other three arches, the centre one being apparently somewhat larger than the two others. There are two distinct lines of roadway, separated by the middle support of the bridge: one for carriages passing eastward, and another for those passing in an opposite direction. No separate provision has yet been made for foot passengers, but I believe it is contemplated to add that accommodation at a future time. The roadway is formed of wood, not otherwise covered than with a coating of preparation to resist the action of the weather, mixed with some rough material to give foothold to the horses passing over. The total length of the bridge is about, I should say, 400 feet. The whole building is well defended by strong side rails and balustrades, as well on the outer sides as on the inner line. The three are uniform. The whole of the upper part, above the roadway, is painted of a light colour, and has a very airy appearance. That below the road and under water is covered with tar, &a., and remains of its natural colour, relieving, very much, the appearance of the upper works of the bridge, and giving it a light appearance when viewed from the banks of the river. Returning to the upper works. On a buttress, at either end of the bridge, is raised a lamp, the light from which will serve to show the divisions of the track at night. The approaches to the bridge, on either side, have been well defended, and led up to, by strong fencing-not the primitive split-post and rail bush stuff, but good, legitimate, strong post and rail, well painted. A very good arrangement has been contrived to prevent collision. It consists merely in an application of those "rules of the road" which are practically on the road so little attended to.

See also

• Historic bridges of New South Wales

References

Article about repairs to bridge after near collapse dated 16 March 1990

External links

• Engineering Heritage Sydney, Denison Bridge Commemoration Plaque