Silvertown Tunnel TBM Completes Second Drive

The Tunnel Boring Machine (TBM) named “Jill” has reached another milestone by completing its second drive at the Silvertown Tunnel in London on Sunday July 23rd. This new 1.4km twin-bore road tunnel under the Thames will be the first in London in over 30 years. A modern tunnel combined with a user charge and improved cross-river public transport will improve the reliability and resilience of the wider road network.

The cross passages are planned to be built using sprayed concrete as primary lining followed by waterproofing and reinforced concrete for permanent tunnel support. CPs 3 to 6 will be constructed using ground freezing for temporary ground stabilization. CP1 will be built in treated ground (soft piles) while CP 2 and 7 will be built using groundwater depressurization for the Lambeth Group sediments.

Gall Zeidler Consultants (GZ) are responsible for the developed and detailed design of the special TBM segments for the CP openings, ground freezing and cross passage design.

If you are interested in GZ’s involvement with the project, visit our project page.

View GZ’s footage on the progress of the giant TBM “Jill”:


The second drive at Silvertown commenced on 14th April and completed on 23rd July after.