Union Bridge (Tweed)

Infobox_Bridge
bridge_name= Union Bridge


caption= Union Bridge viewed from Scotland
official_name= Union Bridge
also_known_as= Chain Bridge
carries= 1 lane of roadway
crosses= River Tweed
locale= Northumberland and Scottish Borders
maint= Tweed Bridges Trust
id=
design= Suspension bridge
mainspan= 129 metres (423 ft)
length=
width= 5.5 metres (18 ft)
clearance=
below=
traffic=
open= July 26, 1820
closed=
toll=
map_cue=
map_

map_text=
map_width=
coordinates= coord|55|45|10.04|N|2|6|15.72|W|region:GB_type:landmark
lat=
long= The Union Bridge, also called the Chain Bridge, spans the River Tweed between Horncliffe, Northumberland, England and Fishwick, Borders, Scotland. When it opened in 1820 it was the longest wrought iron suspension bridge in the world with a span of 137 metres (449 ft), and the first vehicular bridge of its type in the United Kingdom.

Although work started on the Menai Suspension Bridge first, Union Bridge was completed earlier. Today it is the oldest suspension bridge still carrying road traffic. It lies on Sustrans Route 1 and the Pennine Cycleway.

The bridge has been maintained by the Tweed Bridges Trust, since the abolition of turnpike tolls in 1883. It is a Grade I listed building and Scheduled Ancient Monument.

Before the opening of the Union Bridge, crossing the river at this point involved an eleven-mile round trip via Berwick-upon-Tweed downstream or a twenty mile trip via Coldstream upstream. (Ladykirk and Norham Bridge did not open until 1888.)

Design and construction

The bridge's longevity may owe something to the fact that it was designed by a Royal Navy officer, Captain Samuel Brown. Brown's first design for the bridge was prepared in 1817, and reviewed by the eminent civil engineer John Rennie. Brown had built an experimental suspension bridge with a span of 110 ft, which impressed Rennie. Nonetheless, Rennie asked for changes to the design of the stone abutments and towers.

Brown would have been familiar with the fact that a wooden sailing ship is not totally rigid and designed the bridge on the same basis. Originally the deck was supported by three chains of iron bar links on each side. In 1902 a pair of wire rope cables was added. The decking is of timber and the whole structure is designed to flex slightly under load. Standing on it when a vehicle crosses is reminiscent of being on a ship. For this reason, traffic is now limited to one vehicle on the bridge at any one time.

The bridge proposal, received consent in July 1819 using an Act of Parliament that had been passed in 1802, and construction began 2 August 1819. It opened on 26 July the following year, with an opening ceremony attended by Robert Stephenson among others. Captain Brown tested the bridge in a curricle towing twelve carts, before a crowd of about 700 spectators crossed. The final cost was GB£6,449.

Refurbishments

In addition to the 1902 addition of cables, the bridge has been strengthened and refurbishment on many occasions. The bridge deck was substantially renewed in 1871, and again in 1974, with the chains reinforced at intervals throughout its life.

The bridge was closed to motor vehicles for several months during 2007. A newspaper report available online (see external links) indicates that the closure happened shortly before 12th April 2007 and was due to one of the bridge hangers breaking. The affected hanger has temporaily been replaced with threaded bar to allow the bridge to reopen to motor vehicles.

References

* Miller, G. (2006) "Union Chain Bridge - Linking Engineering", "Proceedings of the Institution of Civil Engineers. Civil Engineering", 159 (2), p. 88-95, doi|10.1680/cien.2006.159.2.88
* Paxton, R. and Ruddock, T. (1980) "A heritage of bridges between Edinburgh, Kelso and Berwick ", Edinburgh : Institution of Civil Engineers, Edinburgh and East of Scotland Association, 36 p., No ISBN

See also

*Anglo-Scottish border

External links

* [http://www.chainbridgehouse.co.uk/unionbridge.htm Chain Bridge House page] - note their comments about the effects of wind.
* Just as Berwick received special mention in international documents (see At war with Russia?), so the Tweed Bridges Trust continues to receive special mention in [http://www.opsi.gov.uk/si/si1990/Uksi_19900071_en_1.htm The Transport Levying Bodies Regulations] .
* [http://www.sine.ncl.ac.uk/view_structure_information.asp?struct_id=1425 Information from the Structural Images of the North East (SINE) project] , University of Newcastle upon Tyne.
*
* [http://www.familytraits.co.uk/archive_moments_in_time.html Archived photos] Articles of interest around Berwick Upon Tweed, including Union Bridge
* [http://www.berwickshiretoday.co.uk/viewarticle.aspx?articleid=2694739&sectionid=972] Report of the closure of the bridge shortly before 12th April 2007.