Tag Archives: engineer

Kings Weston Iron Bridge history

It is almost a year since the historic Iron Bridge  across Kings Weston Road was hit by a lorry and damaged an severed an important footpath. At last we have some good news to report: Bristol City Council highways team have now started commissioning survey work of the Grade II Listed structure in advance of physical work being undertaken to reopen it.

A structural survey is just one element of the package of information needed to ensure the most sensitive approach is taken in making repairs; A Listed building assessment and heritage report is also being undertaken by the city’s conservation team to ensure that the significance of the structure is understood, and to inform best practice in dismantling and reinstating damaged elements.

John Loudon McAdam (1735-1836)

The bridge was designed by the eminent highways engineer John Louden McAdam who, at the time, was the engineer tasked with improving the turnpike roads around Bristol. In 1819 the lane, a parish road between Kings Weston and Henbury, was turned into a turnpike road and work commenced to improve standards to justify the tolls levied on such routes.

It wasn’t until 1821 that McAdam noted in his observations that labourers had begun lowering the hill and building walls at Kingsweston Hill. This would have formed the deep cutting through which the current road passes. In the following year he notes the formation of a new footpath in association with the same works which is likely to have been the track approaching the old inn from the Sea Mills direction. It’s probable that the iron bridge was installed at the same time, as the completion of these ambitious works. 

Title page of McAdam’s 1825 Observations

The bridge was constructed of more than 130 individual components of both cast and wrought iron. More technically advanced than most similar structures of the period it used a closed-mould casting technique which allowed the incorporation of strengthening flanges to the structure. New work has been undertaken by KWAG, in cooperation with the Council’s conservation team, that sheds light on the construction and fabrication of the bridge. Following a study of the structure a 3D model has been created which will now be used to inform the best approach to restoration. As you can see, for such a small structure, it’s surprisingly complex! 

The city’s highways officers are currently considering options to raise the bridge to remove the possibility of it being hit again in the future. There is also the potential that the whole of the bridge will need to be dismantled and removed before re-installation. As the project develops we hope to be able to report on progress, but physical work is unlikely to begin before spring 2017. 

exploded diagram undertaken by KWAG showing the construction of the Iron Bridge