The Union Bridge (also Union Chain Bridge) is a suspended-deck suspension bridge that 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 Britain.
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 Category A listed building in Scotland and a Grade I listed building in England. It is a Scheduled Ancient Monument in both countries.
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.
In addition to the 1902 addition of cables, the bridge has been strengthened and refurbished 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 12 April 2007 and was due to one of the bridge hangers breaking. The affected hanger has temporarily been replaced with threaded bar to allow the bridge to reopen to motor vehicles.
In December 2008 the bridge was closed to traffic as a result of a landslide.