The Iron Bridge

At first sight the Iron Bridge is smaller and more delicate than its reputation: a single semicircular arch of openwork iron, a little over 30 metres across, leaping the River Severn in a steep wooded gorge in Shropshire. Its importance is out of all proportion to its size. Opened to traffic on 1 January 1781, it was the first major bridge anywhere built of cast iron, and it proved that iron could carry a structure that had always been made of stone or timber. The gorge around it, where coal, iron ore, limestone and fireclay lay close to the surface, was one of the cradles of the Industrial Revolution: at nearby Coalbrookdale, in 1709, Abraham Darby I had first smelted local iron ore with coke.

The idea came from the architect Thomas Farnolls Pritchard, better known for chimneypieces and funeral monuments, who in 1773 suggested an iron bridge to the ironmaster John Wilkinson. A single span was essential: the banks were unstable and boats needed to pass beneath. Pritchard died in December 1777, only a month after work had begun, and it was Abraham Darby III, grandson of the pioneer, who cast and raised the bridge. Because nobody had yet worked out how to join iron on this scale, the foundry borrowed from carpentry: its almost 1,700 parts, weighing some 378 tons in all, are fitted together with mortise-and-tenon and dovetail joints, and pieces that look identical differ by centimetres because each was cast to fit its neighbour. The five ribs went up in the summer of 1779, and a watercolour by the Swedish painter Elias Martin, rediscovered in Stockholm in 1997, is the only known picture of the work in progress. The outer ribs still carry the line "This bridge was cast at Coalbrook-Dale and erected in the year MDCCLXXIX".

The bridge became a sensation. Painters and engravers came to draw it, and an engraving of it hung in Thomas Jefferson's dining room at Monticello. It was the only bridge on the Severn to come through the great flood of February 1795 undamaged, although the gorge's shifting banks kept squeezing it for two centuries; in the 1970s a concrete inverted arch was laid under the riverbed to hold the abutments apart. Closed to vehicles in 1934 and free of pedestrian tolls since 1950, it is now the centrepiece of the Ironbridge Gorge World Heritage Site, inscribed in 1986. Cross it on foot, look down at the ribs from the old tollhouse on the south bank, then walk along the river to see the whole arch reflected in the water with the village of Ironbridge climbing the hillside behind.

Getting there

The bridge stands in the village of Ironbridge in the Ironbridge Gorge, about 6 km from the centre of Telford in Shropshire. The nearest large airport is Manchester Airport (MAN), about 80 km to the north. The gorge's other industrial sites, including Coalbrookdale and Blists Hill Victorian Town, are close by.