Burdekin bridge
Encyclopedia
The Burdekin Bridge 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.
The Bridge was completed in 1957. Construction began 10 years earlier in 1947. 1097 metres (3,600 ft) in length, it is one of the longest multi-span bridges in Australia and longer than Sydney
's Harbour Bridge
, Brisbane
's Story Bridge or Newcastle
's Brooklyn Bridge
.
not built with a firm foothold.
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.
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.
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.
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 train
s which take both lanes on the narrow bridge.
In October 2010 the Burdekin Bridge was recognised as a National Engineering Heritage Landmark.
Burdekin River
The Burdekin River in Queensland, Australia rises on the western slope of the Seaview Range and flows into the Pacific Ocean at Upstart Bay over 200 km to the southeast of the source. The river was first encountered by Europeans during the expedition led by Ludwig Leichhardt in 1845 and named...
between the towns of Ayr
Ayr, Queensland
Ayr is a town in Queensland, Australia near the delta of the Burdekin River, named after the Scottish town of Ayr by the settlers from the United Kingdom...
and Home Hill
Home Hill, Queensland
Home Hill, Queensland is a town in Queensland, Australia at the delta of the Burdekin River. It is a sugarcane growing area with underground water supplies to irrigate crops. At the 2006 census, Home Hill had a population of 2,907.- Geography :...
, Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
.
Located on the Bruce Highway
Bruce Highway
The Bruce Highway is a major highway in Queensland, Australia. Commencing in the state capital, Brisbane, it passes through areas close to the eastern coast to Cairns in Far North Queensland. The route is a part of the Australian National Highway and also part of Highway 1...
which is part of Highway 1
Highway 1 (Australia)
Australia's Highway 1 is a network of highways that circumnavigate the Australian continent, joining all mainland state capitals. At a total length of approximately it is the longest national highway in the world, longer than the Trans-Siberian Highway and the Trans-Canada Highway...
, 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.
The Bridge was completed in 1957. Construction began 10 years earlier in 1947. 1097 metres (3,600 ft) in length, it is one of the longest multi-span bridges in Australia and longer than Sydney
Sydney
Sydney is the most populous city in Australia and the state capital of New South Wales. Sydney is located on Australia's south-east coast of the Tasman Sea. As of June 2010, the greater metropolitan area had an approximate population of 4.6 million people...
's Harbour Bridge
Sydney Harbour Bridge
The Sydney Harbour Bridge is a steel through arch bridge across Sydney Harbour that carries rail, vehicular, bicycle and pedestrian traffic between the Sydney central business district and the North Shore. The dramatic view of the bridge, the harbour, and the nearby Sydney Opera House is an iconic...
, Brisbane
Brisbane
Brisbane is the capital and most populous city in the Australian state of Queensland and the third most populous city in Australia. Brisbane's metropolitan area has a population of over 2 million, and the South East Queensland urban conurbation, centred around Brisbane, encompasses a population of...
's Story Bridge or Newcastle
Newcastle, New South Wales
The Newcastle metropolitan area is the second most populated area in the Australian state of New South Wales and includes most of the Newcastle and Lake Macquarie Local Government Areas...
's Brooklyn Bridge
Brooklyn Bridge
The Brooklyn Bridge is one of the oldest suspension bridges in the United States. Completed in 1883, it connects the New York City boroughs of Manhattan and Brooklyn by spanning the East River...
.
History
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 AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
not built with a firm foothold.
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.
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.
Because the bridge does not have rock foundations but is entirely supported by sand, it is sometimes described as a floating bridge
Pontoon bridge
A pontoon bridge or floating bridge is a bridge that floats on water and in which barge- or boat-like pontoons support the bridge deck and its dynamic loads. While pontoon bridges are usually temporary structures, some are used for long periods of time...
. 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 $
Australian dollar
The Australian dollar is the currency of the Commonwealth of Australia, including Christmas Island, Cocos Islands, and Norfolk Island, as well as the independent Pacific Island states of Kiribati, Nauru and Tuvalu...
6 million. Despite these setbacks, the new bridge greatly assisted in travel between Ayr, Queensland
Ayr, Queensland
Ayr is a town in Queensland, Australia near the delta of the Burdekin River, named after the Scottish town of Ayr by the settlers from the United Kingdom...
and Home Hill, Queensland
Home Hill, Queensland
Home Hill, Queensland is a town in Queensland, Australia at the delta of the Burdekin River. It is a sugarcane growing area with underground water supplies to irrigate crops. At the 2006 census, Home Hill had a population of 2,907.- Geography :...
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.
Due to the special construction of the bridge, with steel beams
Girder
A girder is a support beam used in construction. Girders often have an I-beam cross section for strength, but may also have a box shape, Z shape or other forms. Girder is the term used to denote the main horizontal support of a structure which supports smaller beams...
forming a truss
Truss
In architecture and structural engineering, a truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in...
over the highway, it is regularly being closed to let pass oversize road train
Road train
A road train or roadtrain is a trucking concept used in remote areas of Argentina, Australia, Mexico, the United States and Canada to move freight efficiently. The term "road train" is most often used in Australia. In the U.S. and Canada the terms "triples," "turnpike doubles" and "Rocky Mountain...
s which take both lanes on the narrow bridge.
In October 2010 the Burdekin Bridge was recognised as a National Engineering Heritage Landmark.