66kV Dual Circuit OHL to UG Diversion - Eskdale Park, Whitby, North Yorkshire

Introduction.

Barratt Homes wanted to to build a new housing estate where a dual Circuit 66kV tower line belonging to Northern Powergrid (NPg) crosses their site. Barratts have approached and agreed with NPg for the diversion of the tower lines to be undergrounded through there site. The new Cct's are approximately 1Km in length.

Wootton & Wootton were contracted to carryout excavations, reinstatement, installation of cables, construction of joint bays, installation of joint & terminations and pressure test upon completeion. 

Despite there being many issues on this job with weather, wayleaves & access issues the project was completed on budget and ahead of schedule.

Scope of Works.

To construct a suitable yard & storage area by leveling site and installing 350T of type 1 stone

To excavate trench & lay 1000m of 6 x 160mm ducts in trefoil complete with a 96.5mm fibre duct to NPg specification & reinstate upon completion

To excavate a 11 way road crossing with 6 x 160mm ducts, 4 x 150mm Rigiduct & 1 x 96.5mm Fibre duct all laid in flat formation.  Steel plated and tiled in 3 levels before permanent reinstatement

To construct 3 x double Cct & 1 x single Cct 66kV joint bays complete with concrete floors, close board timbering, roof & sheeting

To blow ropes, clean and prove the new ducted system

To install approx 3000m of 66kV 500mm Cu XLPE/ Pb/  MDPE sheathed cable & 3000m of 66kV 300mm Cu XLPE/ Pb/  MDPE sheathed cable.

To carryout end to end sheath testing

To install 18 x 66kV 3M coldshrink straight joints.

To install 3 x 66kV Tyco straight joints

To install 12 x 66kV ABB APED self supporting sealing ends

To succesfully carryout 2 x 66kV VLF pressure tests (94kV peak test voltage) upon completion