It is now seven years since the first pile was launched on Crossrail. New Civil Engineer has taken a look back over the years to see the progress which has been made to date.
The line was launched on 15 May 2009 by the then transport secretary Baron Adonis and previous mayor of London Boris Johnson. It runs from Reading and Heathrow in the west, through 42km of new tunnels under London to Shenfield and Abbey Wood in the east. Ten new stations are being built and 30 more are being upgraded, integrating new and existing infrastructure.
The £14.8bn project is currently Europe’s largest infrastructure project and is now almost 75% complete with the attention now moving to track installation and rail fit-out following completion of tunnelling.
The new railway, which will be known as the Elizabeth line when services begin in 2018, will be fully integrated with London’s existing transport network and will be operated by Transport for London. New 200m long trains will carry an estimated 200M passengers per year, increasing central London’s rail capacity by 10%.
TBMs in focus
Eight tunnel boring machines (TBMs) have been used in the construction of the Crossrail tunnels. On average, each of the custom made machines have a diameter of 7.1m, weigh 1,000t and measure around 150m in length.
Phyllis and Ada were the first TBMs on site and each tunnelled 6.8km from Westbourne Park towards Farringdon. Elizabeth and Victoria worked to construct the longest Crossrail tunnel drives building 8.3km between Limmo Peninsula, near Canning Town, and Farringdon.
Jessica and Ellie were used to construct the 2.7km tunnel drives from Pudding Mill Lane portal, near Stratford, to Stepney Green. The machines were then dismantled, lifted out of the shaft and transported by road from Stepney Green to Limmo Peninsula, where they were relaunched to drive the 0.9km tunnels from Limmo to Victoria Dock portal. These were the only machines on the project to undertake two separate tunnel drives.
The final two, named Sophia and Mary, were used to construct the 2.9km-long Thames Tunnel between Plumstead portal and North Woolwich portal. They were Crossrail’s only mixed-shield, or “slurry”, TBMs and at 110m in length are slightly shorter than the other machines.
The fastest section of tunnelling was 72m and was completed by Ellie on 16 April 2014. However, generally Crossrail tunnelling progressed at a collective average of 38m per day.