Wind Turbine Tower Collapse Cases: A Historical Overview

Wind turbines are conceived, designed and operated to interact with the environment including through extreme events. However, engineering malpractices combined with human or mechanical errors and defects of constituent members and materials, still derive in hundreds of structural collapse cases annually from which at least 6% have fatal consequences and about the half involve human injury. It seems therefore, necessary to reflect on factual wind turbine performance against the target. The present paper summarises the most severe tubular wind tower collapse incidents recorded over the past four decades, makes an account of the damage and discusses the respective potential causes. The investigation indicates that although accidental load induced by typhoons and wind storms is the most usual reason of failure, fatal events concentrate at either early or late stage of the designed service life. Unexpected load conditions seemed to derive from defective blade positioning or braking which in turn over-stress areas of transition such as joints and openings. On the other hand, a critical examination of design standards suggests that in general, wind turbine towers as designed and built nowadays are stable and reliable. Hence, the chain relationship determined by the design, manufacturing, construction, operation and maintenance, needs enhancement and further cohesion, at the time that our understanding of and adaptation to extreme events continue developing.