Tandem lifting is the process of lifting loads too big or too heavy for just one crane
When is tandem lifting needed:
When, due to the weight or dimensions of the piece to be lifted, it is not possible to do it with a single crane.
Some secondary reasons to require tandem lifting are:
- Moving ships: fuel may move on the inside, changing the center of gravity. This and the awkward shape of vessels makes them a challenge in terms of lifting.
- Helping other cranes: Distributing weight among several cranes makes accidents less likely when moving heavy cargo.
Safety measures are the biggest concern on tandem lifting. Planning beforehand is thus required to avoid accidents, taking on account factors as the following:
- Risk evaluation
- Assigning the responsibilities of competent persons (operators, riggers, stevedores, etc)
- Step-by-step instructions
- Contingency and rescue plans
Tandem lifting risks
- Side loading: Coordinated crane movement is maybe the core task in tandem lifting. Lifting plans take special attention to this aspect to avoid accidents.
- Not symmetrical objects/weights: The load could be higher on one side and exceed the rated capacity of the hoist on this side. To avoid an asymmetric distribution of weight, it is crucial to have the plans of the part that will provide the weight and its center of gravity.
- Lack of expert supervision: The whole tandem lifting operation must be watched out by an expert.
Tandem lifting and containers
Lifting more than one container at the same time has become popular over the years. Taking advantage of the growing capacity of STS cranes, Spreaders have appeared capable of lifting different configurations of groups of containers in a single lift.
As an example, Singflex Twin Spreaders are designed to handle pairs of 2 x 20’, 40’ or 45’ containers. Even more: Modern cranes can even use two of these spreaders at once, allowing more lifts per crane cycle and improving operational efficiency.
If you are looking for some High performance spreaders with tandem lift or want to know more about the tandem lifting, don’t hesitate to contact us
