The 150m long machine broke into the huge underground space at Whitechapel where work is taking place 35 metres below the surface to create over a kilometre of new platform and passenger tunnels for the new Crossrail station.
The TBM began her journey at Limmo Peninsula in east London at the end of 2012 and will now push ahead to finish the longest of the TBM drives at Farringdon in the last quarter of this year.
The completion of this 8.3km drive will mark the end of tunnelling on the massive project.
Now the focus is shifting to the substantial job of fitting out the stations and tunnels.
Crossrail Chief Executive Andrew Wolstenholme said: “Our tunnelling marathon deep beneath the streets of the capital is continuing apace with the construction of the new rail tunnels now three quarters complete.
“Over the past two years, our huge machines have built more than 19 miles of tunnels and removed more than two million tonnes of earth.”
Three of Crossrail’s boring machines have already retired, with a further five still in use.
In the west, the tunnels between the Royal Oak Portal and Farringdon are complete.
In the east, Victoria and Elizabeth have reached Whitechapel (Complete at Farringdon in fourth quarter of 2014); Ellie is heading towards Stepney Green (complete second quarter) and Jessica is being prepared to complete Crossrail’s shortest tunnel drive between Limmo Peninsula and Victoria Dock (complete fourth quarter).
On the south east section of the route, Sophia has finished her drive and Mary is heading under the Thames (complete second quarter 2014).