Overhead Line Crossing - Overhead Line Crossings of Aerial Tramways

Overhead Line Crossings of Aerial Tramways

Overhead lines should cross the route of an aerial tramway only above it, if at all.

The necessary protection distances from overhead lines to the ropes of an aerial tramway are subject to regulations concerning the construction of aerial tramways and overhead lines. In the case of an undercrossing of an aerial tramway, the maximum safety distances between the overhead line and the floor of the aerial tramway cab must be followed absolutely.

In principle, over- and undercrossings of aerial tramways are completely regulated. However, frequently at the range of the crossing section, special precautionary measures are taken. Thus, at overhead line crossings at which the overhead line runs above the rope of the aerial tramway, two catch ropes are occasionally installed to prevent the conductor from falling off the rope of the tramway in case a pylon or insulator were to break. Alternatively, auxiliary cross-bars can be installed on the pylons of the overhead line under the conductors, which prevent the conductor cables from falling in case of an insulator failure on the aerial tramway. Occasionally, the span field of the line over the aerial ropeway can be scaffolded with a rigid construction along its whole length, or at least for the span which crosses the aerial tramway.

At crossings at which the aerial tramway runs above the power line, the line is frequently installed on special masts in the crossing range, which scaffold the line in the area of the aerial tramway crossing. Such a measure is not necessary according to power line regulations, but it is often done because, in case of aerial tramway failure, it is possible to rescue people from the tram without switching off the overhead line. Such constructions may be seen at 110 kV power line crossings of the Penkenbahn at Mayrhofen, the Patscherkofelbahn at Innsbruck and south of Zermatt.