UK consultant Mott MacDonald has been appointed by client National Grid to provide project management services for the replacement of underground electricity cables in London as part of a multi-billion dollar programme to rewire the United Kingdom. The works include 33km of 4m diameter TBM driven tunnel, already awarded to contractor Costain as reported in TJ two weeks ago.
National Grid supplies electricity through a transmission network operating at 400kV and 275kV which connects the three substations at Hackney, St Johns Wood and Willesden to supply points where power is fed into the local distribution system. Within London a network of 275kV cables was installed in the 1960s which are now approaching the end of their technical life. Due to increased electricity demand the cables are to be upgraded and replaced with 400kV cables.
Mott MacDonald’s role on the project will involve the supervision of civil, mechanical and electrical works; risk management, programme controls, construction design and management advice, safety, health and environmental management, change control, environmental advice, planning, and design checks. Mott MacDonald will be assisted by Donaldson Associates on this project, who are providing services relating to the Hackney to Willesden route under a sub-contract.
Project director Michael Francis said, “Replacement of the existing 275kV cables will ensure that the transmission network supplying power to London continues to provide a high level of reliability, while adding then necessary capacity needed to support future demand growth.”
Michael added, “This project makes good use of brownfield sites and underground space which will have a low impact on the environment.”
The main construction works contract commenced at the beginning of October 2010 and is expected to be completed by the end of 2018.