Second drive through on London cable link 13 Mar 2013
Costain News Release
- The second of four deep level London cable tunnel drives is completed for Costain and its tunnelling partners VVB and Joseph Gallagher.
Fig 1. London Power Tunnels total 32km
- The breakthrough at the St John's Wood shaft and substation, near the famous Lord's Cricket Ground, comes almost exactly a year after TBM Evelyn, a 3m diameter Caterpillar dual mode machine, broke ground on its 7.26km eastern drive from the Willesden substation shaft in March 2012.
- "The tunnelling output was reliable," said Andrew Firth, Costain Project Manager. "We built on an efficient launch and maintained good progress. The best single shift advance was more than 50m in 12 hours; the machine performed very well."
- Evelyn is one of two TBMs excavating three deep level tunnels as part the £220 million London Power Tunnels contract for the UK National Grid.
- The first short western drive between Willesden substation and Channel Gate Road in Brent Park was completed by Evelyn in 2012. The latest breakthrough completes the western section of the east-west tunnel between Brent Park, Willesden, and St John's Wood.
- The TBM will now be lifted from the shaft at St John's Wood and transported by road to the Wandsworth launch site just south of the River Thames, where it will begin a 3.5km drive, scheduled to take six months, southwards to Wimbledon in London's south-western suburbs. From here it will be transported back to the Wandsworth launch site for a final northward drive of 9km to Kensal Green and completion of the north-south tunnel. A connection will be made with the east-west tunnel at Kensal Green.
- Costain is operating a second machine, a 4m diameter Herrenknecht EPBM, for the long 13km drive between Hackney substation and shaft in north London eastwards towards St John's Wood. This machine is scheduled to break through next year (2014).
- The new tunnels, the construction contract for which was awarded in 2010, are essential for installing a safe and reliable high voltage electricity transmission network and to ensure London has sufficient transmission infrastructure to support future energy demand.
- Contract scope is for three tunnels of 3m and 4m i.d, of 32km in total length, plus excavation of 14 shafts and associated underground chambers.
Cable tunnel boosts Morgan Sindall results - TunnelTalk, February 2013
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