Engineering Design Consultants

Queensferry Crossing

Eadon Consulting were initially approached in 2014 by Forth Crossing Bridge Constructors to carry out the independent Category 3 check of the welding gantry designs for the new Queensferry Crossing which lies just north of Edinburgh. The crossing, which forms the centrepiece of a major upgrade to the cross-Forth transport corridor in the east of Scotland, is the longest 3-tower, cable-stayed bridge in the world.

The project consists of two types of gantry each weighing around 10 tonnes. Their construction is made up of 3 dimensional steel space frames spanning the full width of the main bridge deck, in two handed half sections. The leading gantry, type A, is about 5m wide and has a cantilevered deck which allows access to work on the deck joint when a new section of the deck needs to be lifted in to place. The following gantry, type B, is 2m wide and is used to carryout follow on works to the underside of the bridge such as painting.

As is often the case with structural designs, it was realised that the complexity of the task required more than a standard solution and so as the project continued Eadon were not only engaged to complete the category 3 checking but also to assist the client with the design of many different types of complex space frame connections.

Eadon’s responsive approach to this additional scope of work led to further growth in the company’s involvement with the rest of the project. Eadon were further employed to write the gantry technical manual and also provide operator training. In addition to this our engineers were responsible for load testing the gantries, and designing the lifting equipment allowing the installation of the gantries on to the bridge. Eadon have provided on going technical support during the bridges construction and have carried out thorough examinations of the 24 gantries after their initial period of use.

In total the scope of Eadon’s work increased ten-fold on the 1.7 mile structure and showcased not only our skills in bridge gantry design but also our commitment to meeting the client’s demands.

For more information regarding our access and lifting equipment design servicesplease telephone 0114 399 0400 or email us. 


Key Facts
  • Location:
  • Client:
    Forth Crossing Bridge Construction
  • Working With:
    Hochtief, American Bridge, Morrison Construction