Queensferry Crossing, UK: scheme, specimen and definition designs

This paper describes the development of the new Queensferry Crossing over the Firth of Forth in Scotland, UK, from feasibility study through concept development to specimen and definition designs that crystallised the form and function of the bridge. It describes the creation of the project-specific design criteria for aspects beyond the standards, such as dynamic wind loading and ship impact risk evaluation. It also describes the evaluation of options and definition of scope within the specimen and definition designs that determined the contract for the bridge and ensured that the constructed bridge satisfied the functional, durability, reliability, aesthetic and maintainability needs that such a vital element of infrastructure required in a prominent location. The three-tower cable-stayed bridge with 650 m main spans and overlapping stay cables sets a new precedent for spans and stay-cable layout for this form of bridge.