Completed in 1901, Hinton Bridge is an Allan timber truss road bridge, and has a lift span which in the past accommodated river steamers that travelled the Hunter River system. Hinton is one of only three lift bridges in the Hunter region. Most of its engineering details are intact, and the bridge is in good condition.
As a timber truss road bridge, it has strong associations with the expansion of the road network and economic activity throughout NSW, and Percy Allan, the designer of this type of truss.
Allan trusses were third in the five-stage design evolution of NSW timber truss bridges, and were a major improvement over the McDonald trusses which preceded them. Allan trusses were 20% cheaper to build than Mc Donald trusses, could carry 50% more load, and were easier to maintain.
The people who live in the area around the bridge value the bridge highly, and as such it has social significance.
Hinton bridge is in the Hunter Region, which has 15 historic road bridges each constructed before 1905. It gains heritage significance from its proximity to the high concentration of other historic bridges.
In 1998 there were 38 surviving Allan trusses in NSW of the 105 built, and 82 timber truss road
bridges survive from the over 400 built.
Hinton bridge is a representative example of Allan timber truss road bridges, and is assessed as being Nationally significant, primarily on the basis of its technical and historical significance.
Date Significance Updated
27 January 1999
Description
Designer
Percy Allan
Builder
****
Construction years
**** - 1901
Physical description
Hinton bridge is an Allan type timber truss road bridge. It has 2 external timber truss spans, each of 28.0m (92ft) and one internal steel truss lift span of 17.8m (58ft). There are 7 timber approach spans at one end and 3 at the other giving the bridge an overall length of 178.6m (586ft).
The bridge is 14.3m (47ft) above the high water line and the centre lift span previously rose another 7.90m (26ft). The lifting span was fixed in position in 1940 as the need for river steamers ceased.
The internal lift span is supported by twin cast iron cylinders. The timber truss spans are supported by timber trestles. The superstructure provides a carriageway with a minimum width of 5.1m.. Guard rails are of post and rail construction over the approach and timber truss spans.
1940 - Lifting span fixed in position.
2007 - A $9.8 million maintenance and capacity improvement program was undertaken to strengthen the trusses, approaches and lift span, which had deteriorated to the extent that a 15 tonne load limit was imposed. Many innovations were incorporated into the bridge design to minimise future ongoing maintenance. The works improved the strength of the bridge, while respecting the original design. The deck of the truss spans was replaced with stress laminated timber (SLT) decks and the approach spans replaced with concrete/timber composite decks. A new steel lift span complete with SLT deck was also installed. The timber trusses were designed so that the steel plates take the traffic loading. The design also included the fabrication of new steel cross girders and traffic barrier railings which replaced the old timber components.
Date condition updated
17 April 2009
History
Historical notes
Hinton bridge is an Allan type timber truss road bridge and was completed in 1901.
Timber truss road bridges have played a significant role in the expansion and improvement of the NSW road network. Prior to the bridges being built, river crossings were often dangerous in times of rain, which caused bulk freight movement to be prohibitively expensive for most agricultural and mining produce. Only the high priced wool clip of the time was able to carry the costs and inconvenience imposed by the generally inadequate river crossings that often existed prior to the trusses construction.
Timber truss bridges were preferred by the Public Works Department from the mid 19th to the early 20th century because they were relatively cheap to construct, and used mostly local materials. The financially troubled governments of the day applied pressure to the Public Works Department to produce as much road and bridge work for as little cost as possible, using local materials. This condition effectively prohibited the use of iron and steel, as these, prior to the construction of the steel works at Newcastle in the early 20th century, had to be imported from England.
Allan trusses were the first truly scientifically engineered timber truss bridges, and incorporate American design ideas for the first time. This is a reflection of the changing mindset of the NSW people, who were slowly accepting that American ideas could be as good as or better than European ones. The high quality and low cost of the Allan truss design entrenched the dominance of timber truss bridges for NSW roads for the next 30 years.
Percy Allan, the designer of Allan truss and other bridges, was a senior engineer of the Public Works Department, and a prominent figure in late 19th century NSW.
Timber truss bridges, and timber bridges generally were so common that NSW was known to travellers as the "timber bridge state".
Listings
Heritage Listing
Reference Number
Gazette Number
Gazette Page
Heritage Act - State Heritage Register
01470
Register of the National Estate
015950
National Trust of Australia register
Heritage Act - s.170 NSW State agency heritage register
Assessment of Significance
Historical Significance
Through the bridge's association with the expansion of the NSW road network, its ability to demonstrate historically important concepts such as the gradual acceptance of NSW people of American design ideas, and its association with Percy Allan, it has historical significance.
Historical Association
****
Aesthetic/Technical Significance
The bridge exhibits the technical excellence of its design, as all of the structural detail is clearly visible. In the context of its landscape it is visually attractive. As such, the bridge has substantial aesthetic significance.
Social Significance
The bridge is highly valued by the nearby Hinton community.
Timber truss bridges are prominent to road travellers, and NSW has in the past been referred to as the "timber truss bridge state". Through this, the complete set of bridges gain some social significance, as they could be said to be held in reasonable esteem by many travellers in NSW.
Research Significance
The bridge is highly technically significant because:
-It is one of only two timber truss bridges with a lift span in the Hunter region
-It is an Allan truss, and is representative of some major technical developments that were made in timber truss design by the Public Works Department.
Rarity
Highly rare because of its lift span and age
Representativenes
Representative of Allan timber truss bridges
Integrity/Intactness
Intact
Assessed Significance
State
References
Type
Author
Year
Title
Written
Department of Main Roads, NSW
1987
Timber Truss Bridge Maintenance Handbook
Written
Fraser, D J
1985
Timber Bridges of New South Wales
Written
Allan, Percy
1924
Highway Bridge Construction. The practice in New South Wales
Study details
Title
Year
Author
Inspected by
Guidelines used
Relative Heritage Significance of all Timber Truss Bridges in NSW