Forth Replacement Crossing - Design Criteria

Transport Scotland is procuring a new cable stayed road bridge across the Forth Estuary, at Queensferry just west of Edinburgh [1]. The crossing [2] will have two main navigation spans each of 650 m supported from 3 towers with an approach viaduct to the south. It is the first major bridge in the UK for which the design is carried out in accordance with Eurocodes, which were officially implemented, along with the UK National Annexes, in April 2010.

A Design Basis document was prepared for use in developing the Specimen Design [3] and as part of the contract documents for a Design and Build Contract. This details project specific design criteria for aspects beyond the standards, such as dynamic wind loading and ship impact conditions and also clarifies how some of the Eurocode rules should be interpreted. Additional design requirements and rules have been specified to cover durability, access facilities, and mechanical and electrical equipment.