vibration dampers

     Under certain conditions OPGW cable in transmission lines are excited to mechanical vibrations by wind. These are causing alternating bending stresses which superpose to the static tensile bending stress. Suspension- and tension points are especially endangered. these stresses cause fatigue breakages of the cable and subsequent breakdown.Efficient protection against aeolian vibration is given by the installation of suitable vibrations dampers.

    Vibration dampers are combined „frictional resonance“ dampers.Vibration dampers dissipate partly the wind power input on the cable to prevent critical cable stresses.

    The vibration damper consists of a messenger wire with specially formed weights fixed on both ends. The clamp, to mount the damper on the cable is fixed between the weights on the messenger wire and transfers the vibrations from the cable to the

messenger wire. The mechanical vibration energy is transformed within the messenger wire to heat caused by friction.

    Every damper is capable to transform a certain amount of vibration energy into heat, without being overloaded. As the vibration energy is increasing with the length of the span, for longer spans several vibration dampers have to be installed.