The Appointed person can also be the supervisor or crane operator, but with a higher level of qualification. The appointed person should be with the lifting project from beginning to end. Good planning is crucial when you want to have two cranes working well together. Everything for each crane should have a twin, with hoists, harnesses, and beams being of the same weight and rating. You also have fewer details to worry about, such as monitoring the quirks of different brands. Having two cranes the same means that they both move and lift at the same rate. It is also a good idea to use cranes of the same brand and model, if possible, as this helps to make a tandem lift safer. EquipmentĮach crane’s lifting capacity goes through a downgrading - to 75% of their limit - if they are to work on a tandem lift. You also want to make sure that preparation and planning are as close to perfect as possible. The added challenge of coordinating a tandem lift means that you need to use the best equipment and the best staff available. SafetyĪs with all lifting scenarios, safety is the single biggest concern for the operators and those nearby. Newer cranes may also be able to communicate with each other to help keep the load stable, level, and safe. The weight distribution is uneven - this is where planning and expertise play a major role. The beams and hoists are separate for each crane. Each crane would have an independent lifting point on the load. This is a common way for two cranes to lift boats and ships in and out of the water. The load would then hang from the centre of the beam - distributing half the weight between each crane.
This requires a special beam, with crane hooks at either end.Ĭrane hooks from each of the cranes would lift one end of the beam. This method employs the use of an equaliser beam with a central load link and pin. The two main methods of lifting in tandem are equalised and unequalised: Equalised Tandem Lift You want to consider the best ways of using your two cranes, depending on the situation and the load. Two smaller cranes can sit apart and spread the weight. Positioning - You may want to use a large single crane, but the ground is too small or unstable to support it.Sharing the weight with another crane lowers the dangers that come with bad weather, unstable ground, or awkward loads. Critical Lifting - Many factors can put a crane over its lifting limit.Ships will often have ballast and fuel that can cause their weight to shift a great deal during a lift.
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