Union Bridge (Tweed)
Coordinates: 55 ° 45 ′ 9 ″ N , 2 ° 6 ′ 24 ″ W.
| Union Bridge | ||
|---|---|---|
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| use | Local road traffic | |
| Subjugated | tweed | |
| place |
Horncliffe , England Fishwick , Scotland |
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| construction | Chain bridge | |
| overall length | 110 m | |
| width | 5.5 m | |
| Number of openings | 1 | |
| Pillar spacing | 132 m | |
| location | ||
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The Union Bridge , also known as the Union Suspension Bridge or Chain Bridge , spans the River Tweed between Horncliffe , Northumberland in England and Fishwick , Scottish Borders in Scotland .
The wrought iron chain bridge was built by the engineer Samuel Brown between August 1819 and July 1820 in less than 12 months, while it took about three years to build a comparable stone bridge. It was the first suspension bridge in Europe that carts could use. Today it is the oldest suspension bridge that is still used for road traffic.
description
The bridge has an unusual, non-symmetrical side view . Your chains are carried at the western, Scottish end of the bridge by an 18 m high brick portal standing directly on the bank , which has a 3.65 m wide and more than 5 m high passage for the road. At the eastern, English end of the bridge, the chains are anchored in a rock wall a little away from the bank, so that the road leads laterally onto the bridge deck and the bridge deck only begins some distance in front of the anchorage. The span of the chains is much larger than the length of the bridge deck. The pillar axes are 132 m (432 ft ) apart, while the bridge deck has a span of only 110 m (361 ft). It is 5.50 m (18 ft) wide.
The bridge deck of the Union Bridge , which is slightly upwardly tensioned, consists of wooden beams that were formerly provided with iron ruts for the wheels of the wagons. The roadway is supported by a total of twelve chains made of approximately 4.5 m long iron rods. Two chains lying close to each other form a strand, three such strands hang on top of each other on both sides, with the connecting elements of the next higher chain being shifted by 1.5 m (5 ft). The vertical hanging rods are attached to the connecting elements of only one strand, so that only every third rod (after renovation every fourth rod see below) is attached to the same chain. Below the bridge, the hanging rods are connected with cross bars that go under the bridge. The chains are passed through the structures at both ends of the bridge and anchored more than 7 m deep in the ground on the western side, while on the eastern side they are attached to the rock wall within the structure. During a later renovation, a wire rope was pulled in above the chains for reinforcement. At the opening ceremony in July 1820, a load test was carried out with 12 loaded wagons with an estimated total weight of 20 tons. After that, the audience could no longer be held back. It was estimated that 700 people were on the bridge at the same time, which corresponds to a weight of about 47 tons. But the bridge withstood this unforeseen stress test without any problems.
Until the opening of the Menai Suspension Bridge , construction of which began earlier but was not completed until 1826, it had the longest span of any modern bridge.
The bridge is a Grade I listed building and a Scheduled Ancient Monument under monument protection .
Individual evidence
- ^ A b c Robert Stevenson : Description of Bridges of Suspension . In: Sir David Brewster, Robert Jameson (Eds.): The Edinburgh Philosophical Journal . tape 5 , no. 10 . A. Constable & Company, Edinburgh 1821, p. 237-252 ( Google Book [accessed January 18, 2014]).
- ↑ At that time, a weight per person of 150 pounds = 68 kg was calculated.
- ↑ The Chagsam Bridge in Tibet, which can only be used by pedestrians , had a comparable span of around 137 m.
Web links
- The Union Chain Bridge
- Union Bridge, Horncliffe. In: Bridges On The Tweed . Retrieved January 18, 2014 .
- Union Bridge. In: Structurae