Untangling the lines through London Bridge Station

The untangling of the railway lines around London Bridge Station has been successfully delivered giving this station a ‘new heart beat’ to run to. As the person leading on the development of the construction sequence this was perhaps a project of a lifetime in terms of scale and complexity.

My role on London Bridge Station began in June 2008 and continued through from the GRIP 2 to 4 development phases until June 2012, where my final input was to ensure handover to the appointed GRIP 5 to 8 contractors and ensure they were fully up to speed on all aspects so that they could drive the scheme forward. Although the plan for the sequence of works was not the obvious option for my peers in railway infrastructure design; in the case of London Bridge Station, an early and collaborative integrated construction planning approach paid off.

It’s important to bear in mind that this project was not just about London Bridge. As part of the Thameslink Programme it’s a key interchange in the London commute, with routes through London Bridge feeding directly to Cannon Street and Charing Cross, as well as Blackfriars and to the Jubilee and Northern lines on the London Underground Line. This ambitious station upgrade is Network Rail’s biggest, delivering up to 18 Thameslink trains an hour, enabling 96 million people to travel through the station annually, and creating a station that will continue to function for the century.

This may seem obvious, but at the early concept stages of most complex infrastructure projects, integrating the thinking of how it is going to be strategically staged is often not part of the thinking until it is too late to readily change the scheme without major impact.

But we worked with station designers, passenger demand & pedestrian modellers and the railway systems designers to propose a construction sequence that would allow the safe and reliable operation of the railway, its safe and efficient construction, whilst minimising the impact on passengers, both through and at the station.  

So, as a team, we all recognised that the station was running at over capacity, we then observed the station during its peak operation and during perturbed situations, and talked to the station management so that we could get a better understanding of where the issues were.  But to ensure the construction sequence ran smoothly, to time and budget, we also considered not just the impacts of construction at the station but also the construction of wider projects that fed into or through the station, including Bermondsey Dive Under. This work informed the wider systems engineering & integration works that WSP worked with Network Rail to define. The construction sequence at London Bridge was a key driver for this works, as an integrated part of Thameslink’s Key Output 2 (KO2) programme.

We needed to deliver a strategic scheme that kept the station open and functional whilst allowing enough construction space to make the project efficient in its delivery. There were options considered that optimised one over the other and the staging sequence that has been delivered was the ‘best compromise’ between the two.

The result of our planning saw a strategic delivery programme for London Bridge Station and Thameslink KO2 works successfully delivered in three broadly 18-month slots. To do this we closed just three platforms at a time, reopening them as they were completed. So, by putting the construction sequence at the heart of the design meant we delivered a highly complex design solution within a robust programme.

We are now at completion and I am pleased to see that our thorough approach to the construction sequence enabled the team to hit all key project deadlines. The complete rebuild of London Bridge Station, which included 15 platforms, 124 major track and signalling stages, as well as new retail and customer service areas, could last for 120 years. The success of the project sequence delivery and the decades of future capacity it will support means this approach is one I‘m keen to incorporate into all WSP rail projects.

This Blog was written by WSP Technical Director, David Carter

Read more about WSP’s work on London Bridge in this Rail Engineer article