Narrows Bridge (Perth) facts for kids
Quick facts for kids Narrows Bridge |
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The Narrows Bridge seen from QV1, showing the two road bridges and the railway bridge.
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| Type | State Registered Place |
| Designated | 23 April 1999 |
| Reference no. | 4795 |
The Narrows Bridge is a very important road and railway crossing over the Swan River in Perth, Western Australia.
It's made up of two road bridges and one railway bridge. They are built at a narrow part of the river, which is why it's called the Narrows. This spot is between Mill Point and Point Lewis. The bridge connects the Mitchell and Kwinana Freeways, linking the northern and southern parts of the city.
The first road bridge opened in 1959. It was the biggest bridge in the world at the time made from a special type of concrete called precast prestressed concrete. To build the northern part of this bridge, a lot of land had to be created by filling in parts of the river.
The bridge was part of the Kwinana Freeway, which was quite short back then. Over the years, the freeway grew longer, and more and more cars used the bridge. Because of this, a second road bridge was opened in 2001, next to the first one. Then, in 2005, a railway bridge was built in the space between the two road bridges. Trains started using the Narrows Bridge in 2007 when the Mandurah line opened.
Contents
Building the First Road Bridge (1959)
| Narrows Bridge Southbound |
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The bridge from Kings Park, around 1959.
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| Coordinates | Lua error in Module:Coordinates at line 614: attempt to index field 'wikibase' (a nil value). |
| Carries | Kwinana Freeway (southbound road lanes) |
| Crosses | Swan River |
| Maintained by | Main Roads Western Australia |
| Heritage status | WA Heritage Register |
| Characteristics | |
| Material | Reinforced concrete |
| Total length | 396.5 m (1,301 ft) |
| Width | 27.4 m (90 ft) |
| Longest span | 98 m (322 ft) |
| Number of spans | 5 |
| Piers in water | 2 |
| History | |
| Designer | Sir William Holford |
| Construction begin | 8 June 1957 |
| Opened | 13 November 1959 |
People thought about building a bridge at this narrow part of the river as early as 1849. A plan for a bridge came up in 1899, but it was too expensive. Serious planning for the bridge finally started in 1947. However, it was put on hold to build new bridges for The Causeway first.
After the new Causeway bridges opened in 1952, traffic into the city doubled. This made people want a bridge at the Narrows even more.
Choosing the Bridge Location
Work to check the bridge site began in August 1954. The idea for the bridge at the Narrows came from the Town Planning Commission. But some people were not happy. They worried the bridge would block the beautiful views of the city. Also, people living in the rich Mill Point area were upset about a big highway being built near their homes.
The chosen spot also meant that about 60 acres (24 hectares) of land had to be created from Mounts Bay. This was done by filling the area with 4.5 million cubic yards (3.4 million cubic metres) of sand. Much of this sand was dug up from Melville Water in the river.
Funding and Approval
The state government started saving money for the new bridge in September 1954. The construction of the bridge was approved by the government, led by Premier Albert Hawke, in November 1954. They approved it quickly because a new traffic link was urgently needed.
The riverbed where the bridge would be built was very soft. It had mud up to 80 feet (24 metres) deep, with sand beds even deeper. An engineer named Ernie Godfrey traveled overseas to learn about building bridges in similar soft ground. He found a British company, Maunsell & Co., to design the bridge.
How the Bridge Was Built
Construction of the road system began in 1956. The contract to build the bridge was signed in March 1957. The bridge was built by a Danish company, Christiani and Nielsen, working with a Western Australian company, J. O. Clough & Son.
The first temporary wooden pole for the construction was put in place in June 1957. The first permanent pole for the bridge was put in on August 18, 1957. Workers started making the special concrete beams in September 1957. The last concrete beam was put into place in June 1959.
During construction, in February 1959, the Deputy Premier, John Tonkin, announced the bridge would be called the Golden West Bridge. But Golden West was also a popular soft drink, so the name was changed.
The bridge cost £1.5 million (about $3 million AUD today). The whole road system cost £3.5 million. It took 2 years and 5 months to build the bridge. The Governor, Charles Gairdner, officially opened it on November 13, 1959. He was also the first person to drive across the new bridge.
The bridge was part of the new Kwinana Freeway, which was 2.4 miles (3.9 km) long. It was called the "most modern highway" in Western Australia. At the time, the Narrows Bridge was the largest bridge in the world made from precast prestressed concrete.
Bridge Design Details
The bridge was designed by G. Maunsell & Partners and William Halford & Partners. The design used prestressed concrete, which was new for bridges in Western Australia. The bridge curves upwards along its length.
Because the soil was so soft, 160 special "Gambia piles" were used for the foundations. These hollow piles were driven into the ground and then filled with concrete.
The bridge has five sections, called spans. The middle span is 320 feet (98 metres) long. The bridge also carries water pipes, gas pipes, and drainage pipes underneath.
There are footpaths 8 feet (2.4 metres) wide on both sides of the bridge. These paths are separated from the road by lightweight aluminum fences. The street lights are built into these fences.
The bridge deck was made by creating individual concrete pieces on the southern river shore. These pieces were then lifted into place and joined together with strong wires. The new bridge could handle 6,000 cars per hour in each direction, with a total of six traffic lanes.
After the Bridge Opened
In 1996, the bridge was strengthened, and decorative lights were added for nighttime. The bridge was added to the state's heritage list in 1999. It was also named an important engineering landmark.
The bridge made it easier to travel to Perth's city center from the south. This caused many more people to move south of the river. As a result, traffic on the bridge grew, leading to daily traffic jams during busy times. Even with an extra lane added, making seven lanes in total, the bridge became the city's worst traffic bottleneck.
Building the Second Road Bridge (2001)
| Narrows Bridge Northbound |
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The second bridge (in the foreground) with its darker road surface.
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| Carries | Kwinana Freeway (northbound road lanes); Northbound railway line |
| Crosses | Swan River |
| Maintained by | Main Roads Western Australia |
Ideas for a second Narrows Bridge came up in the 1970s, but nothing happened. By 1998, the original bridge was carrying 155,000 vehicles every day. This was far more traffic than the bridge was designed for.
In 1998, the state government announced a plan to add four more traffic lanes. This was part of a bigger project to improve the Kwinana Freeway. The Minister for Transport, Eric Charlton, approved building a separate second road bridge next to the original one. This new bridge would be 6 meters (20 feet) away from the first one. It was designed to look very similar to the original.
The building contract was given to Leighton Contractors in March 1999. The designers were Connell Wagner.
How the Second Bridge Was Built
The second bridge was built using a method called "incremental launching." This meant that 28-meter (92-foot) sections were made on the shore. Then, they were pushed out into place as the building went on. The bridge was built in two halves, which were later joined together.
While it was being launched, the bridge rested on temporary poles. These poles were removed once the bridge was fully in place on its permanent supports. About 250 steel poles were needed for the construction.
Building the second bridge faced some delays due to worker strikes and an algal bloom in the Swan River. The bridge finally opened to traffic on February 26, 2001. The new bridge had six lanes, including one for buses. The original bridge was also changed to have six traffic lanes.
Building the Railway Bridge (2005)
| Narrows Rail Bridge | |
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| Carries | Southbound railway line |
| Crosses | Swan River |
| Characteristics | |
| Number of spans | 5 |
| Piers in water | 2 |
| History | |
| Opened | 23 December 2007 |
While the second road bridge was being built, the idea of a new train line, the Mandurah line, became a big topic in politics. The government at the time wanted to build the railway in a different way. But when a new government, led by the Labor party, won the election in 2001, they decided to build the railway across the Narrows Bridge.
A third bridge was needed for the railway because there wasn't enough space planned when the second bridge was built. Leighton Constructions won the contract to build this part of the railway. They built a narrow railway bridge in the 6-meter (20-foot) gap between the two existing road bridges. The eastern side of the northbound road bridge (built in 2001) was also strengthened to hold the northbound railway track.
Construction of the railway bridge was planned to start in July 2005 and finish by December 2005. The first passengers rode trains across the Narrows on December 23, 2007, when the Mandurah line officially opened.
The railway bridge deck was made from nine huge steel beams. Each beam weighed up to 99.5 tonnes (219,000 pounds) and was up to 54 meters (177 feet) long. These beams were built in Kwinana and brought to the site by road. Then, a large crane carefully lowered them into place.
Images for kids
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The bridges viewed from the west at sunset.
