The River Clyst cycle bridge and boardwalk provides an extension to the Exe Estuary National Cycle Route. The project was not only technically challenging but, as it is located in an RSPB reserve, the environmental impact had to be kept to a minimum.
Marley Eternit smooth Antislip Plus deck boards were specified by Devon County Council as the ‘optimum solution for a cycle path’. The smooth boards delivered a low noise solution and the 3 anti-slip inserts were chosen for an extremely low slip risk.
The vision behind the path specification was that visitors to the area would be ‘hidden’ from the birds, to minimise disruption to their natural habitat. Castelled decking can be quite noisy when traveling over it with pushchairs, wheelchairs or cycles. This would not have met the conservation requirements for the RSPB site.
The slip resistant qualities of Marley Eternit’s JB Antislip Plus decking have been independently tested by the Health & Safety Laboratory (HSL). This resulted in a Pendulum Test Value (PTV) score of 69, even when wet, which is significantly above the minimum required score of 33.
Another reason JB Antislip was chosen was following its success for Nutwell Boardwalk in 2008. The timber deck at Nutwell has weathered well and the anti-slip inserts (resin bonded as part of the manufacturing process) have proven extremely durable.
To meet the use class requirements of a project in a coastal estuary, all boards were treated to ‘Use Class’ 4. For total peace-of-mind the timber was pre-cut to size and pre-drilled before ‘Use Class’ 4 preservative treatment. This high specification ensures complete coverage without cut ends onsite and doesn’t leave exposed untreated timber open to the elements.
Logistically, it was impossible to access the site with a large enough crane by road, so the specialist sub-contractor teamed up with Axminster excavators to find a solution, comprising of a bespoke hydraulic lifting platform and rafts, to float the bridge spans to site. All of this had to be done through the narrow estuary channel, working with the ebb tide to pass under bridges that would have been too low at high tide. EMS floated the bridge spans to site and the bridge was installed from the waterway in a 30 minute high tide window.
Once the bridge spans were in place, the timber decking was installed onto it. As the cutting and drilling had been completed during manufacture, the process was more efficient onsite.
The planning and installation of this job by Exeter Maritime Services, demonstrated innovative thinking and precise execution. The team used local knowledge and worked with nature to complete the job.