Identification of critical causes of tower-crane accidents through system thinking and case analysis

Tower-crane accidents occur frequently and often have serious consequences. To identify the critical causes of tower-crane accidents, this study adopted a method that combined system thinking and case analysis. The entirety of tower-crane accident causes was considered as a system, and was divided into six subsystems and 34 causal factors. Information was collected on 141 investigation reports of tower-crane accidents in China from 2013 to 2018. The occurrence frequencies of accident causal factors and situation severities of subsystems were statistically analyzed. A combination of order relationship analysis and decision-making trial and evaluation laboratory methods was used to quantitatively evaluate the correlations among different causal factors, and the results of a comprehensive centrality and causality of 34 causal factors were obtained. Critical causes of tower-crane accidents were identified, including workers' wrong actions, inadequate safety training, inadequate safety inspection, low safety awareness, and safety engineer's mismanagement. To verify the practicability of the system model and identified critical causes, a case study of a typical serious tower-crane accident was conducted. Finally, corresponding recommendations are proposed for tower-crane safety management improvement and accident prevention.