New pylon at 2,490 metres
The highest mast in the entire Atel Transmission Ltd. electricity grid is stationed 2,490 metres above sea level in the Mittelplatten area, which lies between the Etzlital (Silenen, canton of Uri) and Val Milà (Tujetsch, canton of Graubünden). The mast is part of the key 380 kV power line over the Lukmanier pass. In winter, a large snow cornice regularly develops here which could reach up to the conductor cables. To prevent that from happening, it was necessary to blast the cornice and shovel the snow away several times each winter. Atel Transmission Ltd. decided to replace the Mittelplatten mast with another one at the same site, but 16.3 metres taller. This measure will expand the minimum clearance between the cables and the snow to at least 9.2 metres, even if the cornice grows exceptionally large.
The new steel lattice mast will be 43.5 metres tall. The Lukmanier line will be out of service during three weeks of dismantling and assembly, from 21 August to 10 September 2006. The replacement operation will cost around 1 million Swiss francs.
The masts carrying the 380 kV Lavorgo-Mettlen line between Amsteg and Disentis were erected in 1949. In parallel with the mast replacement operation at Mittelplatten, Atel Transmission Ltd. is carrying out a summer replacement of 17 support masts between Sisikon and Ingenbohl overlooking Lake Lucerne (see Atel media release of 10/5/2006).
Aare-Tessin Ltd. for Electricity Corporate Communications