A major re-design in a joint works venture between National Grid and UK Power Networks required that a new 132kV gas-insulated switchgear (GIS) substation be built in the middle of the existing Wimbledon substation. A vast number of designs were required for both diverted services and new connections into the GIS substation, which Mendeco were contracted to manage and deliver. 

Several challenges were overcome including designing bespoke support structures for cable bridge transitions and adopting specialist backfill materials to ensure all circuit incomers and feeders were capable of meeting customer demand (see Figure below). 

Mendeco’s work on this scheme has been praised on more than one occasion, including correcting previous designs by other parties.