Future Fibres was initially approached in August 2010 to provide Acciona Infrastructures with a composite solution for this innovative footbridge design to be built in Cuenca, Spain, for the end of that year. The carbon cables were required to support the bridge platform and meet strength and stretch parameters specified by the bridge designers. The limiting factors on the solution were the cable diameter to suit the concrete walkway sections and the tight time frame in which the project had to be completed.

The final design involved 16 lines of cables, side by side, made up of five individual cables joined with link plates, to achieve the required 216m long, 3m wide foot bridge. Each of the eighty, 43.4m long, solid carbon cables had a working load of approx 95 tonnes, a diameter of 42mm and weighed in at just less than 100kg. Once installed, they were pre-tensioned to 70 tonnes before nearly 700 tonnes of concrete was laid on top.

This innovative composite solution enabled the design team to develop a new concept in bridge technology; one which would not have been possible with standard building materials. Unsupported spans were significantly increased, supporting structure was reduced and installation time and cost were reduced by over 80%.

This is remarkably similar to what composite masts and rigging have achieved for the yachting industry. There is no doubt that composites have enabled designers to design sailing yachts which would not have been physically possible with aluminium masts and rod rigging. Masts are getting taller, superstructure costs are coming down and ease of handling leads to significant reductions in installation, service and repair costs.

The Future Fibres Innovations division is a separate entity within the business. It is tasked with exploiting technology developed across the company and applying the inherent advantages of composite technology to other market sectors.

More information:www.futurefibres.com