The London Borough of Lambeth commissioned us to carry out an Options Study for replacing Hubert Grove footbridge. The primary aim of the study was to enable the client to identify the preferred construction methodology from:
Method A – Replace the deck from outside Network Rail boundaries, from Dolman Street.
Method B – Replace the deck from inside Network Rail boundaries (track mounted cranes).
We reviewed the previous commissions, prepared a feasibility study for a trackside construction method and compared the two methods as part of an Options Study. In addition of that, we conducted surveys and undertook early contractor involvement. This included liaison with Network Rail, and prepare an Outline Approval in Principle for Design Comparisons.
When comparing the options, we identified that a main issue was that trackside replacement required more possession time, with lengthy lead in times and a need for more time working on rail infrastructure. There are very few rail mounted cranes available in the UK to enable the trackside option and trackside replacement would cause less disruption to residents within close proximity of the structure. Neither option could include the ability to make the footbridge accessible to all users.
We prepared the Options Study report to relay these issues and engaged with the client throughout the process. This helped to understand their priorities to inform the relevant comparative data required, design development and keep them up to date with progress. Our team consulted Network Rail to confirm the constraints they may impose on the scheme. This included defining lead in times associated with different types and lengths of possessions, clearance requirements and parapet arrangements. We successfully engaged with specialist consultants for the development of Option 2 and procurement of the surveying.
