Damage to transmission towers under thunderstorm winds: Fid-Bau Portal

Damage to transmission towers under thunderstorm winds

Calotescu, Ileana / Bîrsan, Marius

A thunderstorm downburst, as defined by Fujita (1985) is “a strong downdraft which induces an outburst of damaging winds on or near the ground”. The vertical profile of wind velocities associated with downburst winds are substantially different than those corresponding to the traditional boundary layer vertical profile. In case of thunderstorms, the wind velocity does not increase with height as in the case of synoptic winds but rather maximum values are found around 50m up to 100m and thus inducing larger responses of low‐rise and mid‐rise buildings such as, for example transmission towers. These are structures of extreme ecconomic importance for any country as their damage may affect a considerable number of people. This paper presents a review of damage caused by recent thunderstorm winds to transmission towers in Romania. The date, location and intensity of thunderstorms were identified based on a vast online research of massmedia reports documenting strong wind events and associated damage between 2013 and 2017. Events that have produced partial damage or total collapse to transmission towers are described in detail. Measured wind data provided by the National Meteorological Administration from meteorological stations nearby the location of damage for each event are provided.