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Lee Valley viaduct reconstruction

The project to reconstruct the Lea Valley viaduct was an integral part of Network Rail’s southern region programme of works.

Lee Valley viaduct is a 12 span structure carrying a 2-track, non-electrified railway over Thames Water’s reservoir. The works involved the strengthening of ten of the viaduct’s spans using a light weight foam concrete infill material and reconstruction of the remaining two spans as open steel structures. Other works included demolishing the existing metal decks and replacing them with ballasted track for the full length of the viaduct.

The viaduct’s railway line was in regular use throughout the works, therefore the deck replacement works had to be delivered during two pre-booked possessions. One of which was planned for the Christmas period. Through a process of value engineering and effective programming of resources, we were able to install all four steel deck spans during a single weekend possession lasting only 52 hours. This was welcomed by the client as it delivered this key aspect of the works earlier than originally programmed.

The piling and infill works were carried out in a high street environment, reducing the construction safety risks to our workforce. Track settlement was actively monitored throughout the construction period, ensuring the safety of trains running on these operational lines.