RAB Associates

The busy A55 Chester to Bangor trunk road, along the pretty North Wales Coast, takes a constant stream of heavy goods vehicles to and from the sea port ferry at Holyhead. As well as being a major tourist route, this road has to take local industrial traffic.

Many of the inspection chambers, which have been sited in the wheel track area, require constant re-bedding in order to prevent the dislodged, loosened cover and frames from becoming a safety hazard. These repairs require carrying out every 18 to 24 months and Conwy County Borough Highways Department obviously considered this too often! Therefore, they called in RAB Associates to advise, design and specify a cost-effective, long-term solution.

Clearly this had to be addressed using the most advanced method of ironwork bedding compounds. Conwy Highways Department had tried several proprietary systems such as Polyester, Epoxy and Polyuride Resins, all with limited success to date.

RAB’s solution was to remove the cast iron cover and frames, remove any loosened brickwork and/or concrete reducing rings. The surrounding distressed road surfacing was also removed.

Using ‘Permatrack Compounds’ the re-bedding to match adjacent levels of the previous items could be quickly completed.

The repair was finalised by the introduction of ‘Permatrack’ and pre-coated high PSV chippings to fill the surrounding void, which now matches the existing road levels.

The highways engineer and his inspectors approved of the ‘Permatrack System’ and when asked to say “why” responded:

• ‘It works’
• ‘It’s quick to install’
• ‘Shorter shut down periods are planned’