Abstract
The main task of this paper is to calculate wind dependent failure rates for overhead transmission lines using reanalysis data and a Bayesian updating scheme. The availability of finely meshed hourly reanalysis time series for wind speed allows us to construct individual fragility curves for each transmission line by considering the failure probability of each of its segments as a function of weather exposure where both segment length and the intensity of wind has been included. Using historical failure data together with a Bayesian updating scheme we are able to construct historical hourly time series for the probability of transmission line failure. These time series form the basis of a Monte Carlo simulation that enables us to capture the significant increase in probability of the occurrence of two or more simultaneous failures associated with severe storms.