Crossrail contractors are due to crane in the project’s third and fourth tunnel boring machines (TBM) at Limmo Peninsula in east London this week.
Contracting joint venture for the Eastern Running Tunnels Dragados-Sisk is lifting in the two TBMs to begin tunnelling towards Farringdon station 8.2km to the west. Dragados-Sisk was due to start the lift on Sunday but it was delayed by strong winds.
Unlike at Westbourne Park, where the TBMs were assembled before being driven into the Royal Oak portal, Dragados-Sisk must assemble the two 150m long Herrenknecht TBMs on site first before lowering them through newly constructed shafts.
The front of the TBMs, including the cutter heads, will be craned in through the 30m diameter main shaft. The tail end, including the muck-away components, will be then transported through the 27m diameter auxiliary shaft.
Once the TBMs are fully assembled underground contractors can then begin constructing the conveyor system to take spoil away from the twin TBMs.
The TBMs are due to reach Farringdon by the third quarter of 2014, before being transported back to Limmo Peninsula. From there one of the TBMs will be used to tunnel east between Limmo Peninsula and the Victoria Dock portal.
Crossrail: Eastern running tunnel TBMs lowered into Limmo shafts