University ofSouthampton
Elstree to St John’s Wood 400 kV Cable Tunnel
Professor Steve Swingler
System Overlay Philosophy
275 kV system is over 40 years oldNew build to be at 400 kVMinimise public impactMinimise disruption to existing system during construction
St John’s Wood: Aerial Shot
Construction Issues: Substations
SpaceSite accessTraffic managementSite clearanceConstruction worksImpact on local communityArchitecture
Why Dig a Tunnel?
Reduced public disruption during constructionReduced programme risk Secure environment for cableFuture provision for second circuit
The Tunnel Route
Technical Details
400kV XLPE cable circuit2500 mm2 Copper conductorForced air coolingDTS monitoring and controlPD Couplers installed in accessoriesSingle circuit
The Tunnel
Construction Issues: Tunnel Shaft Sites
Site availabilitySite accessTraffic managementSpoil removalImpact on local communityHeadworks
Kilburn Grange Park:Aerial Shot
Kilburn Grange Park:Headhouse and New Entrance
Tunnel Layout
Consultations and Communications Strategy
Introductory open meetingsOngoing discussion forumsFreephone serviceProgramme updatesAdvertsLocal community support
Project Identity
London Infrastructure Project: Summary
System installed and operatingCommissioning test from ElstreePD measurements during testMajor consultation exercise