All Crossrail TBMs in the Herrenknecht basketSep 2011
Shani Wallis, TunnelTalk
There it is, a clean sweep on Crossrail for Herrenknecht. Confirmation this week that the last two machines needed for the project's crossing of the Thames to the east of London have also been ordered from Herrenknecht brings a total of eight machines to be supplied by the German manufacturer for London's €14.5 billion mega railway project.
All eight TBMs for Crossrail on order with Herrenknecht
The last two machines are slurry Mixshields ordered by the Hochtief/Murphy JV to complete the twin 2.6km drives under the Thames through fractured chalk that presents the possibility of operating under the full hydrostatic pressure of the river above. The contract is a repeat for Hochtief/Murphy of the river crossing it completed for the Channel Tunnel Rail Link (CTRL) in the early 2000s, also using Herrenknecht Mixshields. The slurry TBMs will launch from Plumstead Portal in late 2012 and drive westwards under the river to North Woolwich. Construction of the Plumstead Portal is now under way with work for the North Woolwich Portal commencing in early 2012.
With the Thames machines, Herrenknecht will also deliver six EPB machines for working predominantly through London Clay between portals at Royal Oak in the west, Pudding Mill Lane at about mid point and Victoria Dock Portal to the east. Four of the machines are for the Dragados/J. Sisk JV for 8.3km of 6.2m diameter tunnels in three drives from Limmo Peninsula west to Farringdon, from Limmo Peninsula east to Victoria Dock, and from Stepney Green north to Pudding Mill Lane for the C305 Eastern Running Tunnels contract, and two are for the BAM Nuttall/Ferrovial Agroman/Kier JV for the 6.2km of twin 6.2m diameter Western Running Tunnels from Royal Oak to Farringdon for contract C300 (Table 1).
Table 1. Tunnel construction schedule
Location
Drive length
TBM Launch
Drive Complete
Royal Oak to Farringdon (Drive X)
2 x 6.1km
Second Quarter 2012
Third Quarter 2013
Limmo Peninsula to Farringdon (Drive Y)
2 x 8.3km
Third Quarter 2012
Third Quarter 2014
Pudding Mill Lane to Stepney Green (Drive Z)
2 x 2.7km
Fourth Quarter 2013
Third Quarter 2014
Limmo Peninsula to Victoria Dock Portal (Drive G)
2 x 900m
Second Quarter 2014
Third Quarter 2014
Limmo Peninsula to Victoria Dock Portal (Drive G)
2 x 900m
Second Quarter 2014
Third Quarter 2014
Plumstead to North Woolwich (Drive H)
2 x 2.6km
Fourth Quarter 2012
Second Quarter 2014
Total TBM bored tunnel
42km
TBM start early 2012
All complete by end 2014
"Work to manufacture the components for the first two machines will shortly complete allowing them to be fully assembled and tested at the factory before being disassembled and transported to the UK in December and January for tunnelling to start at the Royal Oak Portal near Paddington in Spring 2012," said Andy Mitchell, Crossrail Programme Director. "The following six machines will be delivered to Tilbury Docks through 2012. All TBMs will be in the ground by the end of 2012 and all are scheduled to have completed the tunnel drives by the end of 2014."
Segment casting yards for each of the contracts are currently being established for each contract. BAM Nuttall/Ferrovial Agroman/Kier is establishing a casting yard on railway land at Old Oak Common that is on track to be completed later this year. Arrangements are being finalised for locations of the segment manufacturing sites for the other two contracts.
When operational, the Old Oak Common
facility for BAM Nuttall/Ferrovial Agroman/Kier will have 216 moulds to produce the 75,000 concrete segments needed to line the western running tunnels at a production rate of more than 200 segments/day at peak. The plant will employ about 50 people.
At his presentation to the British Tunnelling Society last week (15 Sept, 2011), Mitchell explained that about 85% of the muck to be excavated by the project under the centre of London is to be transported by barges on the river and to a main disposal site on Wallasea Island in the Thames estuary. The rest will be moved by rail or road to land fill sites or facilities for secondary-use processing. Contract C807 for the river transport operation is currently out for bid, he said.
At peak between 2013 and 2015, up to 14,000 people will be employed on Crossrail contracts.
Thank you for taking the time to share your thoughts and comments. You share in the wider tunnelling community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language professional.
Your feedback has been submitted successfully and is currently under review.