- Tunnel boring machine Caroline has passed 1.1km beneath the
River Thames, marking a major milestone in National
Grid's Grain to Tilbury project
- More than 40,000 tonnes of material have been
excavated and over 5,100 pre-cast concrete tunnel segments
installed to form the tunnel lining
- Grain to Tilbury is part of The Great Grid Upgrade, the
largest overhaul of the electricity grid in generations
National Grid has reached the halfway point in the
construction of a new 2.2km high-voltage electricity cable
tunnel between Tilbury in Essex and Gravesend in
Kent, with tunnel boring machine (TBM) Caroline progressing
more than 1.1km beneath the River Thames.
This achievement marks a significant step in replacing the
existing Thames Cable Tunnel, which has been in service since the
late 1960s and is approaching the end of its
operational life.
Part of National Grid's The Great Grid Upgrade, the project will
help strengthen the electricity network and support the continued
connection of secure, cleaner and home-grown sources of
energy to homes and businesses across the UK.
Since tunnelling began in May, significant progress has
been made beneath one of the UK's busiest waterways. More than
40,000 tonnes of material have
been excavated and over 5,100 pre-cast concrete tunnel
segments installed to form the tunnel lining. Just over 840 rings
have been installed, and the tunnelling team has
achieved its best daily performance of 29 tunnel rings
installed within a 24-hour period.
Weighing 464 tonnes, the TBM, together with
the trailing gear, is excavating the tunnel using a
specialist Mixshield system. Named
after pioneering electrical engineer Caroline Haslett, TBM
Caroline has been designed to operate safely in the
challenging ground conditions beneath the Thames.
The milestone follows a series of major achievements on the
project, including the launch of "Verena", Europe's largest
diameter Vertical Shaft Sinking Machine, which was used to
construct the tunnel access shafts at
Tilbury and Gravesend.
The Grain to Tilbury project is being delivered by National Grid
in partnership with Ferrovial BEMO JV and tunnelling
specialist Herrenknecht.
Mark Farmer, Project Director, National Grid,
said:
"Reaching the halfway point of tunnelling beneath the
River Thames is an important moment for the Grain to
Tilbury project and is a testament to the expertise and
collaboration of teams across National Grid and our
partners. The progress made so far reflects the
dedication of everyone involved and moves us a step closer
to delivering infrastructure that will help strengthen
the electricity network and support Britain's future energy
needs."
Borja Trashorras, Project Director, Ferrovial BEMO JV,
said:
Reaching the halfway point beneath the River Thames
reflects the expertise and collaboration of the entire
project team. Delivering more than 1.1km of tunnel safely through
complex ground conditions, while maintaining strong
productivity and environmental performance, is a testament to the
planning, engineering and innovation at the heart of
this project. We're proud of the progress made so far
and remain focused on carrying that momentum forward as Caroline
continues her journey towards a breakthrough later this
year.
Ulrich Schaffhauser, Member of the
Board, Herrenknecht AG, said:
National Grid's Grain to Tilbury project is a benchmark
project in every respect. It is impressive to see what can be
achieved when tailor-made technology and professional project
execution come together. Congratulations to the dedicated team on
site for reaching the halfway milestone, and best wishes for a
safe and successful completion of the tunnel works.
Notes to editors
About Grain to Tilbury
The Grain to Tilbury project is replacing the 1960s Thames Cable
Tunnel, which is reaching the end of its operational life. The
works are taking place beneath the Thames between Tilbury and
Gravesend, as part of the wider The Great Grid Upgrade, the
largest overhaul of the network in a generation.
The project also includes the full refurbishment of the
existing overhead line between Tilbury, Kingsnorth, and the Isle
of Grain, increasing capacity so more electricity can be
transported across the network.
