Statement of Special Interest
A group with the Marriage House (see separate listing).
A very fine example of an 18th century bridge design by pre eminent civil engineer John Smeaton, his first example of a bridge executed in fine dressed sandstone with classical detailing and forming a prominent structure in the landscape of the border between Scotland and England. The bridge is a seminal example of British civil engineering significantly influencing the design and construction of bridges of this period and beyond.
John Smeaton, (1724-1792) is highly regarded as making a significant contribution to the built heritage of the 18th century through his broad engineering prowess which spanned a wide spectrum to included bridges, mills, lighthouses, canals, harbours as well as major contributions to engineering science. He is widely renowned as Britain's first civil engineer and responsible for many important innovative structures such as the third Eddystone lighthouse (1755-9) which was to become the prototype for all masonry lighthouses built in the open sea. During this project he identified the compositional requirements needed to create hydraulic lime which allowed mortar to be more efficiently used under water. Smeaton is known for 4 prominent bridges, Coldstream, Hexham, Perth and Banff, Coldstream being the first where he adopted the roundel oculi detailing which was to become his hallmark on subsequent bridges. From the mid 18th century the design of major bridges developed lighter structures with flatter arches. In Coldstream the main arches were all built the same size to save on shuttering costs.
The architect Robert Reid of Haddington, who had prepared initial designs for the bridge in 1762, became local overseer of the project built to Smeaton's plans. It was Smeaton's second design which incorporated ornament and detailing from Reid's earlier plan. Work began in July 1763 and the bridge was opened to traffic on October 28th 1766.
Coldstream Bridge was commissioned by local road trustees and the Tweed Bridges Trust costing £6000 and spanning 173 metres. The bridge toll house (Marriage House, see separate listing) was built separately by Robert Reid with a second storey below road level to form a house for himself arguing that the two storey structure would help support the bridge structure. Smeaton supported this theory when the road trustees disapproved of Reid's plan for his own house. The cottage was often used for elopements due to its location and became known as the Marriage House.
The bridge has undergone 20th century alterations including strengthening its piers and rebuilding the parapet in 1922 and renewing its internal structure, provision of reinforcing concrete relieving arches and the widening of the roadway with cantilevered footpaths in 1960-61. The alterations however are subtle and do not detract from the imposing character of the original 18th century bridge design. The weir slightly downstream was added c1784.
Formally a Scheduled Monument, de - scheduled (July 2012). List description updated 2012 following descheduling. That part of the bridge in England is also listed and included in the list for Cornhill o Tweed Parish, Northumberland.