Video: A look at the Rhyl Foryd Bridge in action.
In response to a tender call from the local authority Denbighshire County Council for a new lifting bridge over Rhyl Harbour, North Wales, engineering consultancy Ramboll and civil engineering company Dawnus developed a design consisting of two mirroring 30 m long decks. The decks are hinged on a central caisson and lifted by cables running up to a central mast.
The bridge, which will be used by pedestrians and cyclists, is likely to be opened several times a day and the council was interested in minimising the use of energy for each lifting operation. The use of moulded structural fibre reinforced plastic (FRP) composite materials for the bridge decks became an integral part of the design to save as much weight as possible to reduce lifting time and reduce power consumption.
Composites also allowed a more sculptured deck shape, which provides a striking, iconic sight when the bridge is opened.
FRP decks save weight
| ... FRP decks would result in considerable weight savings compared with a steel structure. |
Ramboll approached composites manufacturer AM Structures in 2009 to review the concept. Working with structural engineering and composite materials specialist Gurit, AM Structures confirmed that the bridge concept was feasible with some minor changes to the underside geometry, and that the FRP decks would result in considerable weight savings compared with a steel structure.
The updated design proved to be successful and AM Structures was awarded a design and build contract by Dawnus for the fabrication of the two bridge spans.
AM Structures contracted Gurit to carry out the detailed structural engineering of the bridge decks. The decks were manufactured using Gurit’s Corecell™ M-Foam, Ampreg 21 epoxy resin and a mixture of glass and carbon reinforcements.
The bridge, named 'Pont y Draig' (Dragon Bridge), was opened to the public on 22 October 2013.
- To learn more about the design, production and installation of this bridge read the feature article A landmark composite bridge for North Wales, written by Tom Royle, Director of Wizz Consultancy, who developed the quality plan for the project.
