Here's another bridge from London's East End, very different to the last one in both form and function.
It's a footbridge again, but part of a railway station interchange. West Ham station was rebuilt as part of the Jubilee Line Extension project in 1999, and connects together two London Underground lines, one overground rail line and the Docklands Light Railway.
The revamp of West Ham was designed by Van Heyningen and Hayward, with structural engineering by WSP. It's in a much more modest architectural style than most of the JLE stations, several of which are gargantuan in scale, gaining much of their architectural cachet from spectacle rather than subtlety. West Ham was reportedly the least expensive of all the JLE stations, but its dignified simplicity is still very attractive. It's a direct descendant of Charles Holden's classic London Underground station designs such as Oakwood.
The station is set out on a 6 metre square grid, and the platform interchange footbridges stick to this plan.
Most of the station canopies and building are cube-like in nature, but the structural needs of the bridge vary this slightly by incorporating truss diagonals. The spans could have been achieved without these, but it allows the main structural members to retain a certain degree of slenderness. The bridge trusses are in reinforced concrete, in keeping with the design vocabulary of the rest of the station, which mixes concrete, brick, and glass blocks.
The bridge is uncluttered, minimalist in style, and the use of glass blocks allows in plenty of light while avoiding the shopping-centre feel that conventional glazing might have have presented. It's unusual to see a reinforced concrete truss bridge in the modern era, but it makes sense in this context. The covered footbridge is always a difficult design challenge, and this is an excellent response to it. Later in this series of posts, I'll feature a very different taken on the covered footbridge problem.