Crossrail celebrates Stepney Green breakthrough

Crossrail reached a crossroads earlier this month, 40 m below ground, as its 1,000-tonne tunnel boring machine Elizabeth broke into one of Europe’s largest mined caverns below Stepney Green in the East End of London.

Elizabeth, along with sister machine Victoria, is completing the longest tunnel drive on the Crossrail project, from Limmo Peninsula near Canning Town to Farringdon, a distance of 8.3 km.

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

The Stepney Green caverns are some of the largest mined caverns ever built in Europe using a tunnelling technique called sprayed concrete lining. They are approximately 50m long, 17m wide and 15m high.

Stepney Green will mark the point where the railway divides with the southeast spur running underground to Canary Wharf, Woolwich and then onto Abbey Wood. The northeast spur runs from Stepney Green through Pudding Mill Lane, Stratford, and then on to Shenfield in Essex.

From Stepney Green, Elizabeth will undergo maintenance works before resuming tunnelling towards Whitechapel, Liverpool Street and Farringdon.

Crossrail is Europe’s largest construction project and includes 42km (26 miles) of 6.2m diameter tunnels built up to 40m beneath central London and Docklands. Over 14 miles of tunnels, more than half of the total, are now complete.