In some parts of Italy characterised by a particular morphology, accumulation of wet snow on conductors of overhead power lines generates important mechanical overloads that are among the major causes of damage to overhead power lines and power outages in winter.

When wet snow accumulates on the windward part of a conductor, this rotates due to the applied torque, which increases the accumulation of wet snow and leads to the formation of a complete and greater sleeve. In order to investigate this mechanism and the possibility of mitigating the formation of sleeves on overhead lines, the torsional stiffness of different overhead line conductors was calculated and characterised, and the behaviour of torsion detuning pendulums was tested.

In this regard, characterisations of the behaviour of torsion detuning pendulums under the effects of wind vibrations were also carried out.

Evaluations were also carried out on the possible use of interphase spacers.

The results allowed us to consider the installation of these devices on lines in operation and their behaviour in the presence of wind vibrations.

The report also examined the behaviour of aramid yarn core conductors in relation to creeping, following the anomalous behaviour recorded during the experiments conducted during the previous Annual Implementation Plan, which confirmed the need for additional studies and experiments before considering a possible application in the field

The report also mentions international standards (IEC TC7 and IEC TC11) on high temperature conductors and composite material core conductors in particulars; RSE, TERNA and Italian major manufacturers of conductors and terminals are at the forefront in the developments of these type of standards.