History of the Union Chain Bridge
Captain Samuel Brown’s Union Chain Bridge over the River Tweed near Paxton is a majestic, extremely important and yet seemingly hidden, wrought iron suspension bridge. Some have described its design, and that of others, as a ‘web of iron,’ conjuring an image of a spider throwing its delicate, glimmering threads across a valley. It ‘unites’ England with Scotland and, completed in 1820, is fast approaching its 200th birthday.
The original crossing was a perilous ford, slightly downstream from where the bridge was eventually built. When the river was high there could be loss of cargo and even of life, and until the completion of the Union Bridge no other bridge crossed the Tweed between Berwick and Coldstream. In addition to the risk posed by the ford, it was a need to the transport coal and lime from Northumberland to Berwickshire where it was used in agriculture that further warranted the construction of a new bridge.
Fortunately, there were important acts of parliament which, from the 17th up until the 19th century, encouraged the improvement of infrastructure, including the Union Chain Bridge. Turnpike Trusts were created with powers to collect tolls for maintaining the principal roads and bridges in Britain. The £7,700 needed to construct the Union Bridge was provided by Berwick and North Durham Turnpike Trust. This amount was roughly one third of what it would have cost to build a masonry bridge and the construction time of just 11 months was significantly less too.
Once the Trustees were able to fund a bridge, all they needed was a method and this is where fate came into play. Captain Samuel Brown RN, a retired naval captain, was developing, with much determination and fervour, wrought iron chains and links at a works he had set up at Millwall on the Isle of Dogs. Brown’s invention, which he in turn tested and patented, lent itself completely to the construction of a suspension bridge – and he knew it. So much so he built a 105 ft long replica to prove his theory.
With Brown’s confidence, ambition and determination to succeed, the Union Chain Bridge could come into being. One would imagine the activities of others, such as Thomas Telford, could only spur him on. Although work on Telford’s Menai Bridge began before work commenced on the Union Bridge, the Union Bridge was completed first, making it, at 449ft/137m, the longest iron suspension bridge in the world when it opened. It was also the first bridge of its type to carry vehicles.
Brown had turned to the production of wrought iron chains after being affected by the loss of Royal Naval ships which had broken free from their weak hempen ropes. Together with his main financier and collaborator, his cousin Samuel Lennox, Brown ultimately supplied rigging chains to the Royal Navy until 1926. Lenox had an iron works in Newbridge, South Wales and it was from here that the fabric of the Union Bridge came.
It was with great celebration and fanfare that the Union Chain Bridge was opened on the 26th July 1820. Some of the most important engineers of the day were present, including the Scottish civil engineers Robert Stevenson and John Rennie. Its strength was demonstrated with a procession of loaded curricles followed by 600 eager spectators.
At 146 metres (480ft) the span of the suspension chains were several times larger than anything for many years. The bridge’s deck was made from timber, with a span of 120metres (390ft). The bridge is embedded into the rock on the English side, but hung from a free-standing support tower on the Scottish side. This design was finalised with consultation from both Rennie and Stevenson.
To pay for its upkeep tolls were collected at a small house on the English side of the bridge. In 1883 this collection of tolls ended, and so in 1884 The Tweed Bridges Trust became its new custodians. In 1903 additional cables were added in order to strengthen the bridge. Later, in 1955 the toll house, which housed a family across only two rooms, was deemed unsuitable for habitation and was demolished, although the foundations can still be seen.
Unfortunately, and possibly because Brown was a pioneer working with what were new technologies, most of his other constructions eventually failed. Both his Trinity Chain Pier at Newhaven, Edinburgh and his Brighton Chain Pier were destroyed by a storms. His railway suspension bridge across the Tees had to be replaced.
What cannot be doubted is the influence of Brown’s patented inventions. It is interesting to note that Brunel’s design for the Clifton Suspension Bridge borrows much from Brown’s Union Bridge design and that Brown himself entered the competition for the Clifton Bridge, coming third behind two designs submitted by a young Brunel. The famous photograph of Brunel taken in 1857 shows the engineer posing in front of chains produced by Brown Lenox & Co.
Until the 1970s the bridge existed with little maintenance – apart from the additional steel wire cable – but in 1973 a detailed inspection was carried out by the county surveyor. The importance of the bridge both to local users and to the history of civil engineering as a whole prompted the commencement of repair work in May 1974. The bridge was closed for 6 months and the entire deck was replaced.
Today, the bridge is maintained by Northumberland County Council. It is a Grade 1 listed building, and it has received no major attention since its 1974 overhaul, apart from the replacement of some fractured hangars in 2007. It is estimated by Scottish Borders Council that a complete refurbishment of the bridge would cost £4.7 million (£2.35 million from either authority).
A depiction of the bridge commissioned by the trustees and painted before its completion by Alexander Naysmith can be seen on display at Paxton House. It was presented as a gift to Samuel Brown in recognition of his great achievement.