The UK’s two biggest rail infrastructure projects, Thameslink and Crossrail, will meet at Farringdon Station.
The station is being transformed through the Thameslink programme, which will mean longer and more frequent trains.
The station will also have a new ticket hall for Thameslink and Crossrail services, a new concourse and entrance in the current station building along with a new roof and footbridge. All these works are being carried out whilst the station remains open, presenting a huge logistical challenge.
Combining the new with the old
The busy 1860s, Grade II listed station is owned by London Underground and presently combines Tube services (Metropolitan, Circle and Hammersmith & City) with the national rail network’s Thameslink route.
With work well underway, a network of seven, 1 second robotic theodolites, known as Cyclops, have been installed throughout the station to monitor discreet areas of London Underground assets as well as third-party properties. The instruments operate within groups and provide a rigid, highly accurate movement monitoring survey network.
The Cyclops network feeds data back to the contractor’s office in real time, enabling engineers to easily access current and historical data through SolData’s Geoscope software. Automatic triggers have been set up to notify key members of the construction team via email and text message should any displacement exceed these trigger values.
This system enables the team to accurately determine the structural performance around their site works and, where necessary, provide mitigating actions. Regular remote interrogation of the system by the SolData data engineer determines the current performance parameters of these networks, allowing the optimisation of the system necessary to achieve the required accuracies.
In addition to the movement monitoring, a network of 6 geophones installed on the Cowcross Street bridge, platforms areas and equipment buildings allow induced vibrations around the site to be recorded and evaluated. This is particularly relevant during critical phases of the works, such as the partial demolition of the existing station structure and the piling works to accommodate the new station layout.
Results are logged and managed through the Gorgone system, providing real time station vibration levels which in turn are presented and stored on the Geoscope software. Network Rail is delivering the government funded Thameslink programme, with a joint venture of Costain/Laing O’Rourke, the contractor at Farringdon. SolData is the specialist monitoring contractor for Costain/Laing O’Rourke.