Ordsall Chord, Manchester: design of the UK's first network arch bridge

Abstract

As part of the Northern Hub project to improve rail travel in the North of England, Network Rail is building a new section of railway in Manchester. The Ordsall Chord will provide a direct link between the city's Piccadilly and Victoria stations, which will allow trains arriving from the east to reach Manchester Airport without congesting Piccadilly. The new link will require the construction of 330m of elevated railway viaduct. The viaduct will deviate from the mainline alongside Grade I and II listed structures, crossing the River Irwell and a dual carriageway to merge into existing lines. The challenges posed by designing such an ambitious project in a city location led to a myriad of structural options being considered. The selected option for the River Irwell span was an 89m single-span network arch bridge. On completion, the bridge will not only be the first network arch bridge in the UK, but also the second-longest in the world to carry twin heavy-rail tracks. This article gives an overview of the initial design processes that led to the proposition, recommendation and selection of the network arch-type bridge for this particular span within the overall system.