Crossrail reached another milestone on Wednesday when a 1,000 tonne tunnel boring machine broke into one of Europe’s largest mined caverns, 40m below Stepney Green.

East London Advertiser: Major tunnelling on Crossrail is expected to be completed by the end of 2014Major tunnelling on Crossrail is expected to be completed by the end of 2014 (Image: Archant)

Since being launched last winter, two machines - Elizabeth and Victoria - have been working to create the longest tunnel drive as part of the £14.8bn project.

They are covering just over eight kilometres from Limmo Peninsula near Canning Town to Farringdon, and on Wednesday, Elizabeth broke into the Stepney Green caverns.

The caverns are about 50m long, 17m wide and 15m high.

The machines have already passed through the new Canary Wharf Crossrail station during the summer.

Crossrail will pass through 38 stations and run more than 100km from Maidenhead and Heathrow in the west, through new twin-bore 21km tunnels below central London to Shenfield and Abbey Wood in the east.

Tunnelling machine Elizabeth will now undergo maintenance inside Stepney Green’s westbound cavern before resuming tunnelling towards Whitechapel, Liverpool Street and Farringdon.

The breakthrough is the first of four that will take place at Stepney Green, with Victoria due to break through into the site in the next few weeks.

A Crossrail spokesman said Stepney Green will play a “critical role” when Crossrail opens in 2018, as it is where the railway divides with the southeast spur running onto Abbey Wood and the northeast spur running on to Shenfield.

Click on the link above to view more images of the engineering feat.