The London Connection - Planning and Design of a High Voltage Cable Tunnel Supplying Power to Central London

摘要

The paper describes the planning and design of the 20 km-long cable tunnel between Elstree in Hertfordshire and St John's Wood in Westminster, part of the National Grid Company's programme to upgrade and strengthen supplies to London. This project has a number of challenges in terms of project management, with two separate major contractors for tunnel construction and supply of the high voltage cables. In addition, there are complex interfaces with new sub-stations to be constructed both at Elstree and St John's Wood. The design of the alignment is discussed, with reference to the relationship to other underground structures and the assessment of geological conditions, based on a ground investigation programme. Confirming the route alignment by obtaining wayleaves for the underground alignment and permission for buildings at the shaft sites has controlled the scheme planning process.