Designing the River Irwell Crossing – the UK’s first network arch bridge

The first railway network arch bridge in the UK is due for completion in the summer of 2017 and will support a new railway line that connects the Piccadilly and Victoria Stations in the heart of Manchester. Set alongside heritage structures of huge significance, aesthetics is paramount and has led to an asymmetric network arch form to satisfy the aspiration for a landmark bridge. The highly constrained site necessitated an unconventional piecemeal erection sequence over the river on asymmetric temporary towers. This required a detailed erection analysis of a complex methodology and special measures had to be taken to facilitate erection within acceptable construction tolerances. The paper provides an outline description of the design challenges that the project posed and how they were addressed.