VVB

Power & Utilities - London Power Tunnels

London Power Tunnels

Contract Value £20m:

In February 2011 National Grid embarked upon a seven‐year project to construct a deep underground tunnel network across London to install 200km of high voltage cabling (400kV) in order to meet increasing electricity demand and to help access renewable energy possibilities for the future. The project involves the construction of an East to West tunnel drive from Willesdon in North West London to Hackney in East London, along with a North to South tunnel construction running from Kensal Green down to Wimbledon in the South West of London.

The London Power Tunnels project will create a new 32km electricity superhighway deep below the capital, which will help keep Londoners connected to safe and reliable electricity supplies. The main tunnel drives were successfully completed in March 2015 and the remainder of the project is due to be complete and fully operational by 2018.

VVB Engineering have been awarded 4 contracts to support the works from the initial early works contract in which the temporary power supplies were established to support the tunnel drives and set up site power at the four substations (Hackney, St John’s Wood, Willesdon and Wimbledon) as well as the two tunnel drive sites at Eade Road and Wandsworth.

VVB were involved in the procurement of the two tunnel boring machines (TBM), named ‘Cleopatra’ and ‘Evelyn’. The works undertaken by VVB progressed to the design of the permanent mechanical and electrical infrastructure for the operational requirements for the tunnel system. VVB are currently working on the permanent fit out of the tunnels.

VVB Engineering have been working closely with this programme from the early planning stages and with the tunnelling works now complete the project has moved into its next phase, to connect the 4 existing substations and to construct two additional substations as well as the construction of head houses to support the 14 shafts along the route and the electrical fit out of the tunnelling system.

The project team are responsible for the management of all mechanical, electrical and communications works. Activities of the installation to the head houses and tunnel shafts cover the mechanical, electrical and communications systems, from gas detection and fire alarm systems to SCADA, lighting and security systems.
VVB are responsible for the testing and commissioning of works, providing calculations and information on system requirements and preparation of operation and maintenance manuals for hand over to the client.

VVB has worked as part of the London Power Tunnels (LPT) project for 5 years. The scope of works VVB has undertaken has been complex and extensive and includes the following;

  • M&E site establishments
  • The temporary M&E systems associated with the tunnel works, including the maintenance of the tunnel boring machines (TBMs). Design and installation of the temporary HV power supplies for operating the TBMs, tunnel lighting, ventilation, mechanical services (cooling, fire‐main and drainage).
  • Management of the M&E design process
  • Procurement and installation of the M&E systems, including; Tunnel Ventilation Systems, electrical distribution, lighting, CCTV, security, fire systems, distributed temperature sensing systems, HVAC, tunnel vehicle system (monorail), radio communications, SCADA, drainage, hoists.
  • Testing & Commissioning of all M&E systems
  • Handover and training of all National Grid operation personnel.

Permanent Works

Innovation and input into the design of mechanical and electrical systems and the long term operation of tunnel cooling systems. Design construction and procurement/manufacture of a bespoke tunnel vehicle solution. Installation of permanent tunnel works including high voltage brackets, monorail beams and systems, radio systems, M&E fit out of tunnels and headhouses and installation of ventilation systems, fire alarm systems, gas monitoring, distribution temperature systems, SCADA, permanent LV supplies and commissioning of this plant to National Grid procedures and processes.

Temporary Works During Construction

Support during the construction phase included; design and procurement of tunnelling systems. Site setup, LV supplies and operation of LV a suitable LV network, spray concrete lined shaft and adit works. Crucially VVB played a key role in both tunnel boring machine (TBM) assemblies all TBM launches and removal. A further key activity and responsibility was that of TBM maintenance and support during operation.

“All permanent works in headhouses have been completed to the highest standard and the M&E systems deployed across LPT are seen as a step change for National Grid (particularly the running arrangement of fans and innovation in our tunnel vehicle systems). Throughout the project VVB has proved to be a collaborative and mature organisation, willing to work with the client team to overcome issues. It has been a pleasure working with VVB on LPT I would welcome the opportunity to work with them in the future.”
— National Grid, Senior Project Manager