Synopsis
Cody Dock, near the mouth of London's River Lea, is being brought back into use following years of dereliction. A new steel footbridge was commissioned to span over the dock mouth. The bridge allows the passage of vessels into the dock by rolling along a track such that the deck turns upside down and is lifted clear of the navigation envelope. The bridge is carefully counterweighted so the centre of gravity is approximately level, allowing the 13.2t structure to roll using only a hand-cranked winch. Despite the simplicity of this movement, the design process and fabrication revealed complex and unique engineering challenges. This article gives an overview of these, as well as discussing in more detail how certain complexities associated with the delivery of the project were overcome.