|Locale||Mortlake and Chiswick|
|Maintained by||Transport for London|
|Preceded by||Kew Railway Bridge|
|Followed by||Barnes Railway Bridge|
|Design||Deck arch bridge|
|Material||Reinforced concrete, Portland stone|
|Total length||606 feet (185 m)|
|Width||70 feet (21 m)|
|Longest span||150 feet (46 m)|
|No. of spans||5|
|Piers in water||2|
|Clearance below||39 feet (12 m) at lowest astronomical tide|
|Designer||Sir Herbert Baker and Alfred Dryland|
|Cleveland Bridge & Engineering Company|
|Opened||3 July 1933|
|Daily traffic||39,710 vehicles (2004)|
Chiswick Bridge is a reinforced concrete deck arch bridge over the River Thames in West London. One of three bridges opened in 1933 as part of an ambitious scheme to relieve traffic congestion west of London, it carries the A316 road between Chiswick on the north bank of the Thames and Mortlake on the south bank.
Built on the site of a former ferry, the bridge is 606 feet (185 m) long and faced with 3,400 tons of Portland stone. At the time of its opening its 150-foot (46 m) central span was the longest concrete span over the Thames. The bridge is possibly best known today for its proximity to the end of The Championship Course, the stretch of the Thames used for the Boat Race and other rowing races.
The villages of Chiswick and Mortlake, about 6 miles (9.7 km) west of central London on the north and south banks of the River Thames, had been linked by a ferry since at least the 17th century. Both areas were sparsely populated, so there was little demand for a fixed river crossing at that point.
With the arrival of railways and the London Underground in the 19th century commuting to London became practical and affordable, and the populations of Chiswick and Mortlake grew rapidly. In 1909 the Great Chertsey Road scheme was proposed, which envisaged building a major new road from Hammersmith, then on the outskirts of London, to Chertsey, 18 miles (29 km) west of central London, bypassing the towns of Kingston and Richmond. However, the scheme was abandoned due to costs and arguments between various interested parties over the exact route the road should take.
After the First World War, the population of the west London suburbs continued to grow, thanks to improved rail transport links and the growth in ownership of automobiles. In 1925, the Ministry of Transport convened a conference between Surrey and Middlesex county councils with the aim of reaching a solution to the congestion problem, and the Great Chertsey Road scheme was revived. In 1927, the Royal Commission on Cross-River Traffic approved the scheme to relieve the by then chronic traffic congestion on the existing, mostly narrow, streets in the area, and on the narrow bridges at Richmond Bridge, Kew and Hammersmith. The Ministry of Transport agreed to pay heavy subsidies towards the cost.
A new arterial road, now the A316 road, was given Royal Assent on 3 August 1928, and construction began in 1930. The construction of the road required two new bridges to be built, at Twickenham and Chiswick. The proposal was authorised in 1928 and construction began in the same year. The bridge, along with the newly built Twickenham Bridge and the rebuilt Hampton Court Bridge, was opened by Edward, Prince of Wales on 3 July 1933, and the ferry service was permanently closed.
The new bridge was designed in reinforced concrete by architect Sir Herbert Baker and engineer Alfred Dryland, with additional input from Considère Constructions, at the time Britain's leading specialist in reinforced concrete construction.
The bridge has concrete foundations supporting a five-arch cellular reinforced concrete superstructure. The deck is supported by a concealed lattice of columns and beams rising from the arched superstructure. The structure is faced with 3,400 tons of Portland stone, except for underneath the arches. The bridge is 606 feet (185 m) long, and carries two 15-foot (4.6 m) wide walkways, and a 40-foot (12 m) wide road. At the time it was built, the 150-foot (46 m) central span was the longest concrete span over the Thames.
Unusually for a Thames bridge, only three of Chiswick Bridge's five spans cross the river; the shorter spans at each end of the bridge cross the former towpaths. To allow sufficient clearance for shipping without steep inclines, the approach roads to the bridge are elevated from some distance back from the river.
The bridge was built by the Cleveland Bridge & Engineering Company at a cost of £208,284 (about £14,896,000 in 2021). Additional costs such as building the approach roads and purchasing land brought the total cost of the bridge to £227,600 (about £16,277,000 in 2021).[n 1] The Ministry of Transport paid 75% of the cost, with Surrey and Middlesex county councils paying the remainder.
The bridge was generally well received. Country Life praised the design as "reflecting in its general design the eighteenth century Palladian tradition of Lord Burlington's famous villa at Chiswick".[n 2]
Chiswick Bridge is a major transport route, and the eighth busiest of London's 20 Thames road bridges. It is possibly best known for its proximity to the finishing line of The Championship Course, the stretch of the Thames used for the Boat Race and other rowing events. A University Boat Race Stone on the south bank, and a brightly painted blue and black marker post near the north bank of the river, 370 feet (110 m) downstream of the bridge, mark the end of the course.