Yowaka Bridge near Eden

Item

Name of Item	Yowaka Bridge near Eden
Item Number	4300515
Type of Item	Built
Item Sub-Type	Concrete Beam
Roadloc
Address	**** Princes Highway 14 km north of Eden 2551
Local Government Area	Bega Valley
Owner	Local Government
Current Use	Road bridge
Former Use	Road bridge

Statement of significance

The Yowaka Bridge is of State significance. It demonstrates how bridge designs evolved to address the structural capabilities or reinforced concrete compared to the traditional materials of masonry, timber and steel. It is a fine example of a continuous girder reinforced concrete bridge, a type constructed in a limited period between 1934 and World War 2. It is part of the upgrade of the Princes Highway which commenced in 1924. It includes aesthetic qualities such as shuttering / formwork patterning, curved lines and a light graceful form, which addresses the construction process and structural characteristics unique to reinforced concrete. It is one of four continuous two girder reinforced concrete bridges in NSW and the only example with concrete bearings.

This bridge has been assessed as being of State significance.

Date Significance Updated

14 May 2009

Description

Designer	****
Builder	****

Construction years	**** - 1936
Physical description	Four span, concrete simply supported continuous over pier bridge on a 26 degree skew. It is supported on three internal piers and abutments on both ends. The north end is anchored on to the abutment and the remaining supports have rocker bearings to allow movement to the bridge deck. The deck was widened in 1994. Each of the three piers consists of two octagonal columns about 2.3 metres from the top of the pile cap. A concrete diaphragm connects the two columns at mid-height and is approximately 1.8 metres high. The thickness of the diaphragms is approximately 0.32m. Two of the piers are supported on caissons while the third is supported on driven piles. The overall length of the bridge is 65.22 metres with spans of 14.42m, 18.28m and 14.32 m respectively. The deck is integral with two downstand beams running the full length of the bridge. The beams are curved, with haunches at each support point. Traverse cross beams, integral with the deck span are located between the longitudinal beams at regular intervals. The reinforcement in the original concrete consists of round bars. The concrete finish to the original structure is shutter or board finished and is aesthetically laid in the soffit area and horizontal on the abutments and piers.
Physical Condition and/or Archaeological Potential	Original condition assessment: 'The bridge was in good condition but was damaged by fire as a result of a fuel tanker accident in June 1999.' (Last updated: 24/12/1999.) 2007-08 condition update: 'Fair.' (Last updated: 17/4/09.)
Modifications and dates	Widened in 1994 by overlaying the original deck with reinforced concrete and cantilevering it to the increased width. The longitudinal beams were post-tensioned at the end spans to augment the load carrying capacity.
Date condition updated	17 April 2009

History

Historical notes

The current bridge replaced an earlier timber bridge named Saltwater Bridge. (The Yowaka River was previously known as Saltwater River). Early road construction south of Nowra was not as continuous or well planned as in the Illawarra. The majority of roads were rough bridle tracks and were privately funded. An official line was surveyed in 1859 from Merimbula to Bega. In 1864, the government extended the road from Moruya to Bega. River crossings were problematic and it was not until the 1870s that improvements on river crossings were undertaken in the form of punts or bridges. It is likely that the first Saltwater River bridge was constructed in the 1870s or 1880s. Construction of the current bridge was undertaken as part of improvements to the Princes Highway in the 1930s. It was widened in 1994 to cater for modern traffic demands.

Listings

Heritage Listing	Reference Number	Gazette Number	Gazette Page
Heritage Act - State Heritage Register	01486

Heritage Act - s.170 NSW State agency heritage register

Assessment of Significance

Historical Significance	Yowaka Bridge demonstrates the adoption or reinforced concrete as a relatively new material and the development of reinforced concrete bridge designs, which emerged during the late nineteenth and early twentieth centuries. Continuous girder bridges were one of the five reinforced concrete bridge types developed following the formation of the Main Roads Board in 1924. The bridge forms part of the Princes Highway and was part of the overall improvement works on the highway after the formation of the Main Roads Board.
Historical Association	****
Aesthetic/Technical Significance	The surface form and texture created by the formwork and shutter design on the soffit, abutments and piers demonstrates that the architectural attributes of the bridge were part of the overall design and were not purely utilitarian. The level of detailing present on the soffit indicates that the architectural detailing was as important as the structural design. The subtle arches, level springings and haunches along the main beam / girder complement the structural characteristics and potential of reinforced concrete, which allowed a lighter and more graceful bridge design.
Social Significance	****
Research Significance	The bridge type was developed specifically for the use of reinforced concrete during a period when the material was gaining predominance over masonry and timber as the primary bridge construction material. It demonstrates the high level of knowledge and application of modern engineering and bridge designs in reinforced concrete undertaken by the Main Roads Board.
Rarity	In 1999, one of four continuous two girder reinforced concrete bridges in NSW and the only example with concrete bearings. (Others are Kellys Gully Creek near Warialda Rail; Warialda Creek; Croobyar Creek)
Representativenes	Yowaka Bridge is a fine example of a continuous reinforced concrete girder bridge. It contains all the attributes of a continuous reinforced concrete girder bridge as well as the fine architectural detailing. It is one of only ten such bridges in NSW.
Integrity/Intactness	****
Assessed Significance	State

References

Type	Author	Year	Title
Graphic	Department of Main Roads, NSW	1938	General Plan and Elevation of Bridge over Warialda Creek

Graphic	Department of Main Roads NSW	1934	General Plan and Elevation of Bridge over Kellys Gully

Graphic	Department of Main Roads, NSW	1934	General Plan and Elevation of Bridge over Saltwater Creek

Written	Roads and Maritime Services (replacing Roads and Traffic Authority)		Bridge Inspection Reports - General file No. 1108, 1123, 1514, 1225

Study details

Title	Year	Author	Inspected by	Guidelines used
Yowaka River Bridge Heritage Assessment and Statement of Heritage Impact	1999	Heritage Design Services, DPWS		Yes

Custom fields

Roads and Maritime Services (replacing Roads and Traffic Authority) Region	Southern
Bridge Number	5997
CARMS File Number	1/32.1696
Property Number	Bridge
Conservation Management Plan	****

Images