First iron bridge. The Iron Bridge spanning the River Severn at Coalbrookedale in Shropshire, Britain. Completed in 1779 it was the first cast iron bridge in the world to be built and has come to be regarded as a symbol of the beginning of the Industrial Revolution. Iron Bridge is also one of the last of its type to have survived intact. Its main designer was Thomas Farnolls Pritchard, and it was erected by Abraham Darby III in just three months using sections made in a local foundry. Supported by five parallel curved ribs, each almost 61 metres (m) in length, the bridge has a span of 30m and stands 12m above the river. The bridge contains about 385,082 kilogrammes of iron.