Clifton Suspension Bridge
Clifton Suspension Bridge, Designed by Isambard Kingdom Brunel. The bridge has a span of 216m and crosses the Avon Gorge, Bristol, UK. The bridge opened in 1864.
In the mid 18th Century, William Vick who was a wealthy Bristol merchant dreamt of there being a bridge across the Avon Gorge linking Clifton with the private estates of Leigh Woods. He died in 1754, in his will he left the sum of £1000 to be reinvested until it reached the value of £10,000 which he thought would be adequate to pay for a stone bridge across the gorge.
It took until 1829 for the money to have reached a value of £8000, a committee was set up to work out how to put this bridge across the Avon Gorge, but it was realised that £10,000 was only a tiny fraction of the money needed to build a stone bridge or any other sort of bridge.
An iron suspension bridge would be cheaper and changes were made to the plans. A competition was launched in 1829 to find a winning design, Thomas Telford, who was the leading civil engineer of the time was appointed to judge the competition. He rejected all the entries, giving the reason that it was not possible to build a suspension bridge wider than his bridge across the Menai Straits with a span of 176metres that was completed three years earlier in 1826. Telford then submitted his own design and declared himself the winner, this was greatly unpopular and a second competition was launched in 1830, this time with a panel of judges.
On the 16th of March 1831 Isambard Kingdom Brunel was formally announced the winner, with a fashionable Egyptian design. The foundation stone of the new bridge was laid on 21st June 1831. The Bristol Queens Square riots of 29th October 1831 halted construction work on the bridge, the riots severely affected commercial confidence in the city and drove away bridge investors. Work on the bridge did not resume until 1836, but ceased again in 1843 when the funds were exhausted. At this time the towers had been built in unfinished stone and some of the ironwork was ready, however the ironworks were then sold off.
It was not until after Brunel's death in 1859 that any further work on the bridge was carried out, some of Brunel's friends at the Institution of Civil Engineers thought that it would be a good memorial to Brunel to complete his bridge.
In 1860 the Hungerford Suspension bridge over the River Thames in London, built by Brunel in 1845 was demolished to make way for a rail bridge into the new Charing Cross railway station, the wrought iron chains from this bridge were purchased to be used on the Clifton Suspension Bridge. Modifications to the design for Clifton Suspension Bridge were made by engineers William Henry Barlow and John Hawkshaw, the modifications increased the width and strength of the bridge deck, a further chain was added to each side and the towers were left as unfinished stone to help keep the cost of the project down. New investors were found, this enabled work to resume in 1862 and the bridge was completed in 1864.
To demonstrate the bridge was safe to the government inspectors 500tons of stone was placed on the roadway – the bridge sagged by only 15cm and returned to its original position as soon as the load was removed.
Clifton Suspension Bridge was finally opened in December 1864.
Today the bridge is still in use as a road bridge with up to 12000 vehicles crossing the bridge every day, vehicles that cross the bridge are restricted to a maximum weight of four tons.
The Bridge has a span of 216metres between the towers and is 9.5metres wide. The towers stand 26metres above the bridge deck, which is 76metres above the high tide level of the River Avon.
This photograph was taken from a camera lofted by a kite flown from Observatory Hill.
12 September 2009