A passive mechanical anti-sway system for automated container transfer cranes using spiral torsion springs: Modeling, simulation and experimental validation

Container sway limits positioning accuracy, safety, and handling efficiency in automated container terminals. Existing anti-sway solutions often involve complex structures, high maintenance costs, or limited robustness under varying loads. This study proposes a passive anti-sway system using spiral torsion spring modules and clutch-assisted intermittent engagement. The system converts sway-induced kinetic energy into elastic strain energy and dissipates residual energy through a braking unit, avoiding continuous active control. A coupled crane-payload dynamic model is established using the Lagrange method, and the spring modules are designed according to engineering standards. Multibody simulations under rated-load and no-load conditions show that the system reduces unilateral sway amplitude to below 100 mm within 2.5 oscillation cycles under rated load. Prototype tests confirm an approximately linear relationship between spring rotation angle and restoring torque, with a 15.30% average deviation from theoretical predictions. The system provides an energy-efficient, low-maintenance solution for short-lift container handling equipment.