Forth Bridge: the restoration challenge

The Forth Bridge is a symbol of engineering excellence and remains an icon for both railway and civil engineers throughout the world. Following in the footsteps of designers Sir Benjamin Baker and Sir John Fowler and contractor Sir William Arrol, this first full restoration project since its opening in 1899 proved to be a significant challenge. In undertaking this unique restoration project, Network Rail and Balfour Beatty were required to understand the dynamics and engineering principles of the bridge. The original design was not conceived with a complex maintenance regime in mind and certainly not the scale and complexity of scaffold access systems. It was a principal concern that the existing structure was never put out of balance by the average of 4000 t of scaffolding, encapsulation, materials and equipment required. The restoration works to the world's first cantilever and Britain's first all-steel bridge were complex and were carried out with its protected status as a grade A listed Victorian engineering icon in mind.