Two main components would make up the substation, these being:
• An indoor 400kV compound to be constructed, owned and operated by National Grid
• A project compound to receive the export cables and raise the voltage to 400kV, owned and operated by London Array.

An indication of the proposed layout of the substation site is given below.

An access road would be constructed to link the substation to the Seasalter Road. The access road will also link to the existing farm building complex at Cleve Farm providing a new access for on-going agricultural operations.

National Grid Compound
The National Grid compound would consist of:
• An overhead line landing compound, where one circuit of the diverted overhead line will be brought down to two steel lattice gantries, which will be between 12m and 16m in height.
• Switchgear and ancillary equipment, housed in a building of approximate dimensions 40m x 20m x 12m in height. This building will also house auxiliary services such as a workshop area and domestic requirements.
• A small emergency diesel generator.

It is proposed that this building, and other similar buildings on the substation site, be clad in profiled aluminium or steel sheet to a colour scheme and external appearance to be agreed with Swale Borough Council.

Project Compound
The main components of the compounds would be:
• Up to six transformers, each separated by a ‘fire-wall’ not exceeding 9m in height. The main body of each transformer will be contained within an individual noise enclosure of approximate dimensions 10m x 20m x 6m in height. The enclosures are most likely to be steel clad structures with noise absorbing material on the inner face of the structure. The colour scheme for the cladding of the noise enclosures will be subject to agreement with Swale Borough Council. The transformer oil coolers and switchgear connections will be outside of the noise enclosures.
• An open area for electrical equipment such as the air-cooled reactors, typically about 4.5m high, and switchgear, typically about 5m high.
• An auxiliary services building about 18m x 9m x 8m in height. It is proposed that this building be clad in profiled aluminium or steel sheet and will be to the same style as the National Grid switchgear building.
• A small emergency diesel generator.
• Fire deluge pump house and tank. The pump house will be about 3.5m high and the deluge tank about 4.4m high.

Lighting
Once operational the substation would be un-manned and normally unlit. Permanent light fittings would be installed around the main plant components and along the main east to west internal road for use by maintenance staff. Temporary mobile lighting may also be used in some circumstances. The access road to the site, from the Seasalter Road, would not normally be lit.

Fencing
The substation would require permanent external fencing to a specified security standard for this type of installation. Fencing will typically be about 2.5m high with security features installed above that. Internal fencing will separate the various compounds within the substation.

Colour schemes
Although there would be separate compounds for National Grid and the project, there will be a common approach to colour schemes and design of buildings, the details of which would be agreed with Swale Borough Council.