elstree to st john’s wood 400 kv cable tunnel - t3-02 - … · 400 kv cable tunnel professor...

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