Background

UK Power Networks (formerly EDF Energy) awarded Clear Route Limited a contract to install test and commission a new 11kV cable between Bankside Substation and Newington House in Central London. The Contract was awarded in 2010 with all works required to be complete by August 2012.

The Scope of works was as follows:
Clear Route Limited has had a close working relationship with UK Power Networks for a number of years and has carried out a range of competitive contracts such as cable installation, Sub Station Builds and term maintenance contracts.

Initial Situation

Due to the ever growing electrical needs of the London power grids placing increased demand upon the electrical infrastructure it needs to be upgraded from time to time. In this case it was most practical to install a new cable to increase capacity. However after conducting an extensive survey of the route it was found that a significant proportion of the route was virtually impassable due to the extreme congestion of the existing utility services already in place.

Key Customer Requirements

UK Power Networks needed the cable to be installed to meet rising demand and to maintain the integrity of their network, to achieve this UK Power Networks required a solution to by – pass the first section of the route. Clear Route Limited by way of a variation proposed the construction of a Cable Tunnel in accordance with the detailed design provided by Parsons Brinkerhoff Power.
The construction and fit out of a tunnel is a highly skilled operation requiring a contractor that possess a long list of competencies and is experienced at confined space working. Clear Route Limited had to draw on all their expertise

Our Response

Clear Route Limited realised that any diversion to the route was not possible as the whole area was very congested with underground services, so instead a cable tunnel was to be constructed, bypassing the Bankside Substation to Sumner Street section of the route.
Clear Route Limited saw this as an opportunity to gain experience in a technically challenging area whilst demonstrating our capability to complete complex civil engineering projects like this.
The design specifications for the tunnel were:

• Bell out and Launch Chamber would consist of a 5 metre internal diameter, smooth bore segmental concrete shaft between two existing brick built underground flues leading to the main substation, with sprayed concrete lined.
• The reception shaft would be a 7 metre internal diameter shaft within private land
• The tunnel itself would be a 110 metre, 2.44 metre internal diameter concrete segmental lined shaft.

Achievements

The project was fully compliant with CDM Regulations with Clear Route Limited acting as the principle contractor.
We consulted a specialist tunneling company, Parsons Brinkerhoff Power for the design of the tunnel as it was not something we had done before.
Clear Route Limited provided project management and construction expertise not available within UK Power Networks. The Project was delivered on time, within budget and to specification.
The high level of technical competence required to complete a task such as this demonstrated the capability of Clear Route Limited to deliver projects such as this, which meets the expectations of the Client in a challenging environment.

Summary

UK Power Networks were happy with the complete package delivered by Clear Route Limited and the Companies have gone on to enjoy close working relationships.
Clear Route Limited is proud to work closely with its customer and meeting their needs by being able to react in a swift and efficient manner to deliver such projects.
This shows Clear Route Limited’s specialist skills and ability to respond to high level technical requirements.