| Queen Elizabeth II Bridge | |
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The Queen Elizabeth II Bridge |
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| Carries | 4 lanes of roadway |
| Crosses | River Thames |
| Locale | Dartford |
| Design | Cable-stayed bridge |
| Total length | 812 m (2,664 ft) |
| Longest span | 450 metres (1,476 ft) |
| Vertical clearance | 57.5 m (189 ft) |
| Opened | 30 October 1991 |
| Daily traffic | 72,700 (2007/8 estimate[1]) |
The Queen Elizabeth II Bridge is a 137 m (449 ft) high and 812 m (2,664 ft) long cable-stayed road bridge across the River Thames in south east England. It was opened in 1991 by Her Majesty Queen Elizabeth II.
The bridge is the southbound element of the Dartford Crossing, a strategic congestion charged road crossing the half mile wide river east of London. It was built alongside two earlier tunnels under the Thames, which now form the northbound element of the crossing.
Upon completion, the bridge was Europe's largest cable-supported bridge. As of 2010 by main span length it is the second largest cable-stayed bridge in the United Kingdom behind the Second Severn Crossing (6 m longer and opened in 1996) and the 44th largest cable-stayed bridge in the world.
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The bridge is the easternmost road bridge crossing the River Thames. At the time of opening it was only the second bridge on the River Thames east (downstream) of London Bridge constructed in over a thousand years. The historic reason for this is that bridges prohibited tall ships and other large ships from reaching the Pool of London, which has led to the building of numerous tunnels instead, until the construction of large bridges became feasible.
The bridge's main span, the length of road deck between its two main towers (pylons), measures 450 metres (1,476 ft). This together with two 181 m outer spans either side gives the bridge an overall suspended road deck length of 812 metres (2,664 ft) metres. The outer spans are also supported underneath by concrete pillars.
Connecting with the bridge's road deck joints are the approach roads, elevated on concrete viaducts. The northern elevated approach is 1,052 m (3,451 ft) long, while the southern elevated approach is 1,008 m (3,307 ft) long. The suspended bridge deck when combined together with the approach viaducts forms a total elevated stretch of road 2,872 m (9,423 ft) long.
The road deck of the bridge is supported by cables attached to 84 m (276 ft) metre high steel pylons rising above the road deck, standing on top of 53 m (174 ft) metre high concrete piers. These give the bridge an overall height of 137 m (449 ft).
The highest point of the road deck rises 65 m (213 ft) above the river, giving a clearance below to shipping of 57.5 m (189 ft) to accommodate all but the largest ocean-going cruise liners (for example the MS Freedom of the Seas is 63.7 m tall above the waterline).
The construction project of the bridge was an early example of a government Private Finance Initiative (PFI) project, whereby the bridge was funded by a private consortium in return for an operating concession. Authorised by a Parliamentary bill in 1988, construction began in August 1988 and was completed on 7 June 1991,[2] with the bridge being officially opened on 30 October 1991. The bridge has an expected life span of 120 years.
The bridge superstructure was designed by German civil engineer Hellmut Homberg.[3] The bridge was his last design as he died in July 1990. The bridge was built by Cleveland Bridge & Engineering Company, at the time part of Trafalgar House plc.[4] Construction of the bridge itself cost £120 million (£203 million as of 2012),[5] with another £30m for the approach road viaducts.[6]
The height of the bridge means that it is sometimes closed due to high winds, accidents or in bad weather. Unlike other major bridges, the traffic disruption that this causes can be mitigated in part by the diversion of traffic through one of the Dartford tunnels which were in place before the bridge opened. Despite this, a closure still generates significant delays.
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