Iver & Yiewsely 66kV Cable Replacement
Working for Scottish & Southern Electricity Networks to support them through delivery to install a 66kV dual circuit between the existing 66kV substations at Iver and Yiewsley. The existing Gas Filled circuits had reached their design life expectancy, and we had separately been involved in PF tagging of these cables to detect existing faults and their repair works.
The route length of 5kM involved a route through urban areas, and across an asbestos landfill site. Removal of contaminated materials and asbestos working practices were required to clear this area.
The route also incorporated 4 HDD’s and an auger bore beneath National Grid live existing 275kV cable assets.
The trenching and installation works were mostly in the native gravel and sand layers of Iver Heath which involved several methods of ground water management to allow safe installation.
Substation works involved transformer outages and cable termination replacement at both substations. The Iver substation involved terminating within the GIS plant and upgrading of existing protection and control.
Services we provided included:
Project Management
Cost Consultancy and Quantity Surveying
Contract Support