Forth Road Bridge – Main Cable Internal Inspection 2025

Description

The Forth Road Bridge is a suspension bridge with a 1006m main span and equal side spans of 408 m and carries a dual 2-lane carriageway and two 4.5m wide foot/cycle ways over the Firth of Forth between Fife and West Lothian. The bridge opened in 1964. The main suspension cables are approximately 600 mm diameter and the angle of the main cable varies along its length. The existing main cable wire is made up of 11,618 high tensile steel wires, 4.98mm in diameter. The cable bands support the deck via the hanger cables. The works include the provision of all temporary, proprietary and permanent works required to enable internal inspections of the selected main cable panels. In delivering the works the SubContractor shall provide all labour, Contractor’s equipment, materials, supervision and management including the alteration and subsequent testing of two existing high level platforms and refurbishment of the main cable compacting and wrapping machines. The internal inspection of the main cables requires the removal of elastomeric wrap and the 3.78 mm diameter wrapping wire, inserting wedges into the exposed main cable to examine the internal wire condition, removing main cable wires for testing, repairing any wire breakages found during the inspection, re-compacting the exposed section of the main cable, reinstating the wire wrapping and installation of the elastomeric wrap over the wrapping wire. In addition, the SubContractor shall be responsible for removal, reinstatement and recommissioning of a dehumidification equipment (sleeves etc.) and reinstatement of any damage to the acoustic monitoring system. The project has an estimated value of 2,000.000GBP