Narrows Bridge
From Wikipedia, the free encyclopedia
The Narrows Bridge is a bridge that connects the Mitchell Freeway and Kwinana Freeway in Perth, Western Australia. It runs over the Swan River at "The Narrows" between Mt Eliza and Mill Point, connecting the northern and southern suburbs of the city. Prior to its construction the only connection between the northern and southern shores of the Swan River between Fremantle and Perth was The Causeway at the eastern side of Perth Water, which is two bridges making connections via Heirisson Island.
Upstream of the bridge, the river widens to an expanse known as Perth Water, and downstream an even larger widening occurs into Matilda Bay and Melville Water.
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[edit] History
The first Narrows Bridge was opened to traffic on November 13, 1959 by the Governor of Western Australia, Sir Charles Gairdner[1]
A lane was later allocated for "peak hour" usage, with automated gates to alternate the direction between north and sound bound depending upon the time of day.
Due to Perth's increasing traffic volumes, a new bridge was built immediately west of the existing bridge and opened in 2001, effectively doubling its carrying capacity. Although similar in appearance the new bridge is very different structurally, being an incrementally launched post-tensioned concrete structure.
A narrow third bridge for the Southern Suburbs Railway was built in 2006 in the 6 metre (19.7 ft) gap between the existing structures. The bridge is made up of nine steel girders, each weighing up to 94 tonnes (103.6 t) and up to 54 metres (177.2 ft) in length. This bridge is used for the southbound track of the railway; the former northbound busway was strengthened and is now used for the northbound railway track.
[edit] Design
The original bridge was designed by G Maunsell & Partners of London. Its length was 335 metres (1100 ft) between abutments, with 5 spans, the central span 98 metres (320 ft). The width of 24 metres (80 ft) designated 21 metres (70 ft) for 6 traffic lanes and 3 metres (10 ft) for footpaths. At the time of completion, the bridge was the world's largest precast prestressed concrete bridge.[2]
The 2001 duplication included carbon fiber reinforcement.
The 2001 duplication was designed by Connell Wagner and constructed by Leighton Contractors. The rail bridge and associated modifications to the original two structures were built by Leighton and designed by GHD. Piling design was by Coffey Geoscience.
[edit] Gallery
 Aerial view of The Narrows Bridge, including the centre railway. |
 Narrows Bridge Plaque. Commenced 1957, A.R.G. Hawke - Premier, J.T. Tonkin - Minister for Works. |
 Narrows Bridge under construction, c. 1957 |
[edit] References
- ^ Edmonds, Jack (editor) (1979) Swan River colony : life in Western Australia since the early colonial settlement, illustrated by pictures from an exhibition mounted by West Australian Newspapers Ltd. as a contribution to celebrations for the state's 150th year Perth : West Australian Newspapers.ISBN 0909699208 - page 88 - aerial photograph of event
- ^ Anon. 1959, World's largest precast prestressed concrete bridge completed, Roads and Road Construction, v. 37, n. 444, pp. 364-367.
[edit] External links
- Narrows Bridge is at coordinates Coordinates:
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