Risk Analysis and Barrier Design of Offshore Wind Power Transportation Based on BN-BowTie

The transportation phase of offshore wind power installation projects, which links onshore manufacturing with offshore installation, is exposed to complex and coupled risks arising from oversized and overweight components, dynamic marine environments, and spatiotemporal coordination among multiple operational stages. A systematic framework integrating the Bayesian Network (BN) and the Bow-Tie model is proposed for quantitative risk assessment and barrier design of offshore wind power equipment transportation. First, thirty risk factors were identified from five dimensions, namely human, material, technical, environmental, and managerial, through literature review, accident case analysis, and two rounds of expert consultation, and a risk evaluation index system was established. Second, prior probabilities of root nodes were determined by aggregating weighted expert judgments with triangular fuzzy numbers; conditional probability tables were generated using the Noisy-OR gate model; and probability inference, criticality importance analysis, and risk forecasting were performed with Netica software (V.5.19). Finally, guided by the criticality ranking, Bow-Tie models were constructed for the five risk factors addressed in the scenario analysis, and multi-level preventive and mitigative barriers were designed. The results show that the overall risk probability of the transportation phase is 3.99%, with both the risk probability level and the risk loss level at Level II, corresponding to a comprehensive safety risk level of Level 3 (medium risk). Insufficient personnel qualifications (x11) and equipment design risks (x24) rank first and second both by posterior probability and by reconstructed critical importance, followed by the accuracy of spudcan punch-through assessment (x31); when the leading factors are set to occur simultaneously, the modelled accident probability rises to 27.6%, an absolute increase of 23.61 percentage points, a factor of approximately 6.9. The proposed BN-BowTie framework organically combines quantitative risk assessment with qualitative barrier design, providing theoretical support and practical guidance for transportation safety management of offshore wind power installation projects.