Posa e recupero di cavi sottomarini per telecomunicazioni: energia e materiali in gioco.

Undersea cables for telecommunications are put out after 20 to 25 years of service in order to be replaced by new type ones that can yield a better service. As a rule, decommissioned cables are retrieved for the part stretching from the shoreline to the line (-30 m). This operation is useful from the environmental standpoint, as at the price of an energy expenditure of about 3 MJ/m an amount of materials having embodied energy as high as 72 times of it are recovered. Still, the larger part of an undersea cable lies offshore and is usually left on the site, so the actual energy recovery is small – just about few units per cent – compared with the energy (embodied + used for laying) required …