UB240/159 Station Road is a single span, simply supported, wrought iron half-through type underbridge, carrying the twin electrified track of the Bathgate to Helensburgh Line over a public road in Kilpatrick, West Dumbartonshire.
The structure comprises three longitudinal built-up plate girders. The central girder is a hogback girder and the edge girders are constant depth which support fish-bellied transverse built-up cross girders and a longitudinally spanning timber deck. The abutment and wingwalls are of stone masonry construction.
In order to increase the RA rating of the structure in line with that required for the route, shear strengthening was carried out on the central main girder.
MHB Consultants were commissioned by AMCO to carry out the GRIP 4 and 5 design for the superstructure strengthening, condition led repairs, timber deck replacement and repainting.
During a disruptive possession of the line, web plating to central main girder was completed and a new transverse spanning hardwood deck with loose laid waterproofing system installed.
The structure was blast cleaned and received a new corrosion protection system capable of providing a 25 year service life.
Description of Services carried out by MHB Consultants
• Topographical survey
• Paint survey
• Structural condition survey of exiting metalwork and masonry
• Single option development and technical approvals
• Detailed design of structural strengthening
• Site support during implementation
• Design and scheduling of condition-led repairs
• Temporary works design