THE IRON BRIDGE - WORLD HERITAGE SITE - SHROPSHIRE

Without the work of Abraham Darby, who in 1709 was the first to make iron ore by smelting coking coal; and John "Iron-Mad" Wilkinson, who pioneered the use of iron in manufacturing with his various innovations, this bridge, and the entire Industrial Revolution it kick-started, would never have happened.

Work began in 1777 to construct an arched bridge across the river Severn in Coalbrookdale. The bridge was designed by John Wilkinson and constructed by Abraham Darby III. It was completed in 1779.

The deck stands 18 m above the river, with a span of 30.63 m. The construction used 384.6 tons of iron, 1,700 individual components were cast individually to ensure they fit with each other. The outer ribs are engraved with the words "This bridge was cast at Coalbrook-Dale and erected in the year MDCCLXXIX".

The cost of the bridge was estimated at £3,250 (£426,353 in today's money) and paid for by subscribers to the project, mainly John "Iron-Mad" Wilkinson himself. The final cost for the build is unknown, but records suggest it could have been as high as £6,000 with the extra cost being covered by Abraham Darby III. The bridge became highly profitable and the tolls were giving the shareholders an annual dividend of over 8%, and iron became the industrial revolution building material.

The bridge was designated a Scheduled Ancient Monument in 1934, and in 1979 was recognised as an International Civil Engineering Landmark by the American Society of civil engineers. Then, in 1983, the bridge became Grade I listed, and three years later was awarded a Unesco World Heritage Site, which included the settlement of Ironbridge.