The Iron Bridge, England

Hefte zur Baukunst, a publication series issued by the Hermann Reemtsma Stiftung, puts the spotlight on architectural structures that are of historic importance, documenting their background, development, and professional restoration.

The second volume in the series is devoted to the Iron Bridge, which crosses the River Servern, in Shropshire, 60km to the northwest of Birmingham. Owing to its vast resources of iron ore and coal, the region is known as the birthplace of Great Britain's Industrial Revolution. In order to establish a reliable link between the mines and factories situated on both sides of the River Severn, an initiative was set up in the 18th century to replace the unstable wooden bridge with a modern iron construction.

The architect Thomas Farnolls Pritchard (1723–1777) and his technical advisor John Wilkinson (1728–1808) designed a structure that had no precedent. They could not draw on any previous data since nobody at the time had any experience with, or had ever calculated, the load-bearing capacity of an iron structure. In the end, the bridge reputedly required a total of 385 tons of cast iron and more than 1,700 individual pieces.

Instead of bolts and rivets, merely dovetails and tenon and mortise joints were used. The Iron Bridge was opened to traffic in 1781, and, in 1986, the structure was designated a UNESCO World Heritage Site. An expert survey conducted in 2000 and in-depth research on materials, surfaces, and construction techniques resulted in a detailed conservation plan, which was successfully carried out in the following years.