The Iron Bridge

The Iron Bridge, Shropshire

The construction of an iron bridge over the River Severn in 1779 was a new leap forward in human technology. With its iconic shape and dramatic location, it was a tourist attraction before it was even built. Over 200 years of wear and tear required an extensive programme of restoration of the bridge by its guardians English Heritage.

The opportunity to closely record the historic structure for the first time resulted in a unique collaboration. In conjunction with the physical survey undertaken by Ironbridge Archaeology and the English Heritage Metric Survey team, a comprehensive re-examination of the historical sources was made by David de Haan of the Ironbridge Institute.

The results of this unique collaboration revealed how the bridge had been put together. This has been derived from the discovery of 'carpenters marks' on the ironwork, as well as sampling of the structure and an analysis of its components.

Although various assembly methods had been suggested over the years, no-one really knew how the bridge was built. This study discovered that the Iron Bridge had used a surprisingly simple but sophisticated technique of ropes and gantries.