24/01/2000
Power Pylons for ENEL
Foster and Partners has been awarded joint first prize in a competition held by ENEL - the Italian National Electricity Company - to design an environmentally sensitive high-voltage power pylon. The other first-prize winner was the team of Achille Castiglioni and Michele de Lucchi. Both designs will be put into production and installed throughout Italy this year.
ENEL is the world's third largest electrical utility, serving more than 28 million consumers. 1000 of its 100,000 staff work in the Research and Development Department.
In response to criticism that its existing high-voltage pylons were insensitive to suburban and rural environments, ENEL organised an international design competition. The new pylons should be less crude and obviously 'agricultural' than traditional models and more organic and sympathetic to the landscape.
Foster and Partners' design is a minimal structure that follows from a thorough re-examination and rationalisation of the pylon's functional and engineering principles. Because they will be manufactured in large numbers, the new pylons are designed to be efficient in terms of materials, manufacturing and installation processes.
The design abandons the conventional and untidy 'Christmas tree' configuration in which cables are supported by arms sprouting at intervals from the pylon's main mast. Instead the cables are neatly grouped within an open V-form, created by the junction of two attenuated masts. Within the V-form the cables are held in an equilateral triangle - the most compact arrangement possible allowing for the necessary safety clearances between each of the cables and the supporting structure.
The pylon arms work structurally as inclined cantilevers, sharing the loads from the transmission cables. The arms connect and form A-frame legs, which open out as they descend towards the ground. The triangular cross-section of the pylon arms and legs does not require diagonal bracing as a square or rectangular section would.
The pylon structure is made of carbon-steel, which is hot-dip galvanised to provide a zero maintenance anti-corrosion protection system. Each pylon is manufactured as eight lightweight pre-fabricated components, enabling transportation to and installation in remote sites. The maximum dimensions of the component parts are determined by individual transportation requirements. The components are bolted together on site and no on-site welding is required.
Foster and Partners' pylon for ENEL is the most recent of the practice's environment-friendly solutions for energy installations in rural areas. Our wind turbine for Enercon, already installed in Germany and England, reduces the noise pollution normally created by wind turbines by eliminating the gearbox from the installation.
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