Our work at Berwyn Viaduct involved two distinct schemes of work.
The first phase followed an initial assessment of the six span Viaduct, which had shown that due to cracking and movement of the masonry, the capacity of the structure was restricted and that there was a risk of further movement and damage occurring to the Viaduct which would have a major impact on the operation of the line.
The principal cause of the weakness of the structure was the failure of the drainage system. Consequently the first phase of the work involved removing all of the fill over the structure, re-opening all the drainage points and constructing a shaped concrete fill over the arches to ensure discharge to the drainage points prior to backfilling with a free draining material.
The second phase of the work involved reinstating the cantilever platform, originally fixed to the side of the Viaduct to provide an extension to the platform at Berwyn Station. The original platform had been removed following the Beeching cuts in the 1960’s.
This work required close consultation with the Local Authority Conservation Officer and CADW (the Welsh equivalent of English Heritage) as the Viaduct is a listed structure. The work was complicated by the fact that it is situated adjacent to the river Dee, which frequently floods and also crosses a further minor road and the site is constricted between the railway and the adjacent A5 trunk road. This required close liaison with a number of statutory bodies including the Highway Authority and the Environment Agency regarding the river.
The project ran extremely smoothly, and was completed on time and to budget.
The success of the project and the authenticity of the reinstatement won us the prestigious Institution of Civil Engineers Historic Bridge and Infrastructure Award 2003.