Dyer & Butler
Refurbishment of Viaduct
Situated southeast of Hayle Station the viaduct carries the Penzance to Paddington main line, constructed circa 185, comprising 36 masonry piers with a deck composed of longitudinal riveted plate girders supporting transverse timber decking and a ballasted track.
Steelwork corrosion to various components of the riveted plate girders and bracing was evident. There was no water-proofing between the ballast and timber decking except at road spans 8 and 20 resulting in timber decay and water percolating down to girders.
Crouch Waterfall designed the permanent refurbishment works of the Viaduct. All major work undertaken during November 2014 in a 16-day 24-hour a day operation with Crouch Waterfall providing full site engineering support throughout. The line was completely closed.
All elements requiring repair or replacement were marked on site as the engineers surveyed all the metallic structure from rivet head loss to flange and web deterioration.
All deck timbers were replaced on a like for like basis using hardwood and zinc galvanised fixings, with new loose laid waterproofing. All steel structure was hand cleaned before laying new timbers.
Timber ballast boards were replaced with steel L sections anchored to the timbers, existing guard rails and timber posts were replaced with galvanised ‘KeeKlamp’ type posts and rails fixed to new ballast plates.
As per Network Rail request the provision of a future canopy was integrated in the design.