ABSTRACT
Crossrail’s Liverpool Street station will serve the City of London and provide interchanges with London Underground’s Northern, Central, Metropolitan, Circle and Hammersmith & City lines, connections to Stansted airport and National rail services at Liverpool Street and Moorgate stations. The Crossrail project management team were highly concerned about the perceived risks associated with elimination of the temporary propping and particularly the potential for damage to the nearby Northern Line tunnel. A detailed flow chart was prepared and presented to the Crossrail project management team, the contractor and external stakeholders in order to explain the implementation of the observational method. Liverpool Street station’s 42 m deep Moorgate shaft was on the critical path for completion of Crossrail’s central tunnelled section. The timely passage of the tunnel boring machine through the Moorgate shaft was fundamental in meeting the Crossrail critical path programme for the opening of the central London section; any delay in the construction of the Moorgate shaft was unacceptable.
