Underpinning - Farringdon Station

Underpinning of Grade II Listed Underground Station

Following difficult but ultimately successful negotiations over two years, Abbey Pynford and Farringdon Station were recently awarded the complex underpinning of the Grade II listed 1865 London Underground station buildings. The works are to be undertaken under the main Station Facade to Farringdon Station for Network Rail as part of the Thameslink upgrade project. Farringdon is one of the earliest underground stations in London being originally opened in 1863 as the Terminus to the Metropolitan railway, the first underground railway in the world.

Abbey Pynford have been employed to design and construct a new Reinforced Concrete structure from Pynford Beams to support the existing Victorian buildings. This in turn be supported by two new large steel plate girders weighing around 10 tonnes each, one of these being delivered by rail slid in below the station. So the works have been carefully designed in a series of phases and sub stages to allow the demolition of existing brickwork barrel arches and installation of the new girders before completion of the structure with RC slabs to form the new floors. The work also involve sensitive jacking to transfer the load of the existing superstructure to the new substructure. The main contractor CoLOR will later demolish the remaining brickwork substructure below our works to build new platform and allow enhanced access for passengers to walk to the new Ticket Hall being constructed for Crossrail on the opposite site.

Much of the work will take place only a few hundred millimetres directly above the overhead power lines and over the live Thameslink railway (see pick). One large Pynford beam is to be installed beneath the main station entrance used by 1.7 million passengers per year. Our work will take place in a combination of normal working hours and Engineering hour possessions (night-time and weekend working) with extremely limited access, so will be particularly challenging for the Abbey Pynford team to complete.

Design is now complete and the £0.9m works are due to start on site shortly which are expected to be completed by Christmas this year.