a ship at sea) must be included in your calculations. At worst, the accelerations and winch-wire velocities of a crane and or mass such as located on a moving base (e.g. Dynamic Amplification Factor (DAF)Ī dynamic amplification factor is a value (greater than 1.0) by which you multiply your static weight in order to determine the total dynamic load you should expect in your lifting system.Ī DAF must always be applied to this weight in order to account for even the minimal dynamic amplification induced by the speed of the winch. It is usual to install a mechanical turnbuckle in at least one of the legs in a four-leg system in order to ensure equally distributed loads or to lift your mass using a three-leg system, which always distributes loads evenly between each leg according to its horizontal distance from the CofG.Ī dynamic amplification factor must always be applied to your static weight, and a safety factor must always be applied to the strength capacity of your lifting system (see Dynamic Amplification Factor and Safety Factor below). the body is to be placed on a tilted surface, the unevenness of the leg lengths should be determined by calculation and the system (leg lengths) should be manufactured accurately. If the legs are not of correct length according to the lift point positioning, the body will suffer from uncontrolled tilt, which is never acceptable (see Safety Factors Quality below). Otherwise the load in each leg will vary. In a configuration where all legs are of exactly the same length and connected to the mass equidistant from the centre of lift and from each other and connected to the lift wire at the same point, the load in each leg will be the same and the body should lift 'flat and even' off a stationary terrain.
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