The Burdekin
Bridge (known as the Burdekin River
Bridge or Silver Link) spans the Burdekin River between the towns of
Ayr and
Home Hill, Queensland, Australia. Located on the Bruce Highway which is part of Highway 1, it is an important link in the national road network. It is a road-rail
bridge which provides high flood immunity link between north and south Queensland.
Burdikin Bridge Construction
New Bridge, Burdekin River 1957
The
Bridge was completed in 1957. Construction began 10 years earlier in 1947. At 1097 metres (3,600 ft) in length, it is one of the longest multi-span bridges in Australia and longer than
Brisbane's Story
Bridge or New South Wales's Hawkesbury River Railway
Bridge. It is 46 metres shorter than
Sydney's Harbour
Bridge.
Originally, it was thought that the
bridge could not be built in its present location. No trace of
rock could be found on which to build the
bridge foundations. In 1946, two high-ranking Government engineers visited India to inspect a number of bridges built on sand foundations. The same technique was used for the Burdekin
Bridge and it is the only
bridge in Australia not built with a firm foothold.
News article from The Proserpine Guardian 14 February 1947
News Paper article in Bowen Independant, April 4th 1947
The
bridge rests on 11 huge, hollow, concrete caissons sunk into the river bed. The caissons are 17 metres across the top (measured parallel to the stream) and vary in width from 5.5 to 7.6 metres. The caissons were sunk into the river bed to a depth of about 30 metres. Add to that the approximately 20 metres that the caissons rise above the bed and the end result is some very massive pieces of concrete. Each weighs about 4,000 tons. The caissons were fitted with steel "cutting edges" to help them sink. The steel used in the cutting edges weighed 238 tons.
Aerial photograph of Burdekin Bridge construction site showing piers with Railway Bridge in foreground 1952
Construction of the first caisson started in 1947 after the "wet season". As each caisson rose in height, sand was removed from the centre of the caisson to make it sink into the sand bed. To get such a tremendous mass to sink gradually and evenly was difficult. To add to the difficulties, often a caisson became stuck and a diver had to be sent down to find the problem and remedy it. Another difficulty was that each caisson had to be sunk to a secure depth before the "wet season". If a caisson was not firmly anchored deep enough, a flood could have swept it away.
Approach to Burdekin, bridge 1957
Burdekin Bridge 1963
My Fathers photo of Burdikin Bridge, 1968
Because the
bridge does not have
rock foundations but is entirely supported by sand, it is sometimes described as a floating
bridge. It is not a true floating
bridge as it does not float on water.
The metal
bridge spans were bolted together with high-tensile bolts instead of being riveted. At the time, no other Australian
bridge had ever been constructed this way.
With all the difficulties, plus the shortage of steel after the Second World War, the construction took almost a decade to complete at a cost of $6 million. Despite these setbacks, the new
bridge greatly assisted in travel between
Ayr, Queensland and
Home Hill, Queensland and formed a vital link between North and South Queensland.
The Silver Link replaced a
bridge which is set just off the river bed. It was regularly covered and washed away by flood waters but it is still possible to see the remains of the
old bridge when the river level is low.
Remains of the old bridge
Due to the special construction of the
bridge, with steel beams forming a truss over the highway, it is regularly being closed to let pass oversize road trains which take both lanes on the narrow
bridge.
In October 2010 the Burdekin
Bridge was recognised as a National Engineering
Heritage Landmark.
Burdikin Bridge 50th year
A 5-year
bridge maintenance and rehabilitation project had commenced in 2013. It is the first major structural rehabilitation work undertaken since the
bridge construction