Forth Road Bridge – A9000 FRB SSUDA Refurbishment, 11 & 12

Tender description

The Forth Road Bridge is a long span suspension bridge which carries the A9000 over the Firth of Forth. It was opened in 1964 and is a Category A listed structure. The bridge has a main span of 1006 metres, and side spans each 408 metres long. The structure supports a dual two-lane carriageway without hard shoulders. The suspended span under deck access (SSUDA) system was designed for the inspection of the suspended span and for carrying out minor remedial works such as painting, replacing bolted connections and maintenance of the deck half joints. The SSUDA system was initially installed in 1981. The two walkways below the pedestrian footpaths/cycleways are designated as the A-Lines. The walkways below each carriageway are the C-Lines, and the D-Line is below the central reservation. The longitudinal stiffening truss, or ‘top chord’ is designated as the B-Line, from which temporary ‘B-Line hangers’ are suspended. Aluminium staging boards and handrails can be fitted to span transversely between the walkways/B-Lines to create safe working platforms, with temporary ladders providing access to the platforms from the footpaths. The SSUDA system requires refurbishment to address advancing corrosion, strengthening to increase its load capacity from 0.7kNm2 to 1.5kNm2 and improvement to address the safety risks to maintenance operatives using roped access to install and remove temporary B-Line hangers. The SSUDA refurbishment scheme has been divided into 12 smaller phases to better coordinate works and improve quality control. Phases 1 to 10 have been previously refurbished. It is proposed that the final two phases, 11 and 12, located at each main tower (PP39N-52N) & (PP36S-52S), will be refurbished in accordance with the previous schemes. Each will be issued as separate tenders over FY26/27. A specification for the requirements of the works will be provided, and the contractor will be required to supply, install, commission and carry out the SSUDA refurbishment. Access will require working at height, therefore suitable qualifications will be required for potential contractors. The Contractor must have demonstrable experience of similar works. The Contractor must also be approved to the applicable sector schemes for these kinds of works.