Mechanical Advantage (MA) and Velocity Ratio (VR) of a Double Purchase Crab Winch under Varying Loads and Efforts

This study explores a double purchase crab winch's mechanical advantage (MA) and velocity ratio (VR) under various load and effort scenarios. In order to provide a view on the winch's effectiveness and operational features, the study intends to test how these parameters are impacted by variations in the applied load and effort. The effort needed to lift various loads, as well as the corresponding distances moved by the effort and the load, were measured using a specially created experimental setup. Although the mechanical advantage changed with the applied load, suggesting the impact of frictional forces, the results show a constant velocity ratio, which is theoretically determined by the winch's geometry. The results help to clarify the practical uses and performance constraints of double purchase crab winches.