Effects of mechanical and aerodynamic damping on the galloping of overhead lines

This paper examines theoretically the effects that mechanical and aerodynamic (drag) dampers can have on the amplitudes of the bulk galloping oscillations of overhead lines. The oscillation amplitudes are calculated using an energy-balance method and the results are presented in a way that allows the two types of damper to be compared. It is shown that, for lines with small vertical phase spacings, mechanical dampers should be more effective in reducing oscillation amplitudes. For lines with larger vertical phase spacings, aerodynamic dampers should be better, provided that a sufficiently large fraction of the span length can be fitted with dampers.