In London, National Grid has commissioned its 20km long, US$348M cable tunnel from Elstree in Hertfordshire, to St John’s Wood in north London. The tunnel was designed and constructed by the Murphy Group, which also built six permanent shafts and access buildings. It contains one of the longest 400kVXLPE cable circuits in Europe. KBR developed the scheme design and helped procure and supervise the works. ABB and Siemens carried out the electrical work.
