Crossrail’s western tunnels contractor BAM, Ferrovial, Kier (BFK) and subcontractor Barhale have been excavating and lining a 15m-diameter emergency access shaft in Holborn, known as the Fisher Street shaft.
The shaft will be used to support tunnelling works to build a large crossover tunnel below Red Lion Square at Holborn, which will allow trains to transfer from one running tunnel to another.
It has been completed nine months ahead of the August 2014 scheduled end date due to re-sequencing the works that allowed for the early completion of permanent waterproofing and concrete lining of the shaft.
In total 7,000m3 of material was excavated as the shaft was dug and lined.
Crossrail worked with UK Power Networks to relocate electricity substation equipment, a requirement before tunnel boring machines Phyllis and Ada could pass under Holborn on their journey between Royal Oak and Farringdon. The partnership saw UK Power Networks perform a difficult project in a tight and congested corner of London as they relocated their switchgear equipment.
Crossrail construction manager Roger Mears said: “These works are key to Crossrail’s success in the Holborn area, and the completion of the excavation and structural lining of the Fisher Street shaft is another milestone in our western tunnels project.”
Last month Camden Council approved Crossrail plans to develop 30,000 square feet of residential space above the shaft after the completion of Crossrail’s works. The HOK-designed, eight-storey development comprises 22 one, two and three bedroom apartments. The shaft itself will remain in place providing emergency access and ventilation to the Crossrail tunnels.