ABB completes £11 million project
ABB has completed an £11 million project to install two 400kV cable circuits running through National Grid’s new Dartford Cable Tunnel under the River Thames. The project combines a major reinforcement to the power system with the replacement of older, obsolete, cables to meet the increasing demand for electricity in London.
The two-year cable replacement programme at Dartford involved the removal of existing 275kV oil-filled cables that ran beneath the road deck of the west Dartford Road Tunnel (DRT), and the construction of a dedicated cable tunnel beneath the Thames, running 2.4km from Littlebrook in Kent to Thurrock in Essex.
ABB’s role in the project has been to work with Sudkabel, the cable manufacturer, to supply, install, commission and test two 400kV cable circuits in the tunnel. These use hightechnology cross-linked polyethylene (XLPE) insulation technology, that requires less maintenance than conventional oil- and gas filled cables. Each circuit requires three cables, one for each phase of the three-phase electricity supply, so six 150mm diameter cables have been installed. ABB has also supplied the cable sealing ends and surge arresters.