Engineering Design Consultants

Heigham Holmes Swing Bridge

The river crossing at Martham Ferry provides access to the environmentally sensitive island of Heigham Homes. This area of land requires ongoing land management to maintain it with access for farm vehicles being important.

The existing swing bridge is a floating pontoon that is raised and lowered onto the concrete abutments by pumping water into and out of the buoyancy tank. The bridge is swung by the operator pulling on a chain linked to the nose of the bridge, which requires a reasonable amount of physical effort. This area of the fens is particularly popular with sailing boats and as such the bridge has to be left in the river open position, this means that when the bridge is swung into the position, once the vehicle has been driven over it, the operator has to go back onto one side of the river, open the bridge and then row back to the other side to carry on their journey. This makes the operation of the bridge very slow and cumbersome.

The bridge is reaching the end of its life and the National Trust are looking to replace it with a new structure that addresses these issues, making it easier for people to operate, as well as safer. Ramboll UK were commissioned to initially carry out a condition survey of the existing bridge, and then to look at the different options for replacing it. Ramboll employed Eadon Consulting to act as specialist subcontractors to review and develop different concepts for the operating mechanism for the bridge.

A number of different bridge concepts were considered including traditional design bascule lift bridges and swing bridges. However due to the surrounding area and architecture, it was felt that a swing bridge similar in concept to the existing pontoon design was the most suitable. A number of operating mechanisms were considered drawing on Eadon's experience of moveable bridge as well as lock gate design. As well as this, Eadon helped assess the feasibility of the pumping system to be used within the buoyancy tanks of the bridge and its effects on the overall operating sequence of the bridge. This information was then used to produce budget costs for the whole project.

The project is now moving forward toward the design phase with Eadon Consulting providing detailed design services for the operating mechanism as well as developing the hydraulic and electrical control systems.

For more information or to discuss your moving bridge or swing bridge requirements, please telephone 0114 399 0400 or email us.

Key Facts
  • Location:
    Heigham Holmes, Norfolk
  • Client:
    Specialist Sub-consultant to Ramboll UK