Mammoet launches wind turbine cranes

Leading international heavy lifting and transport specialist Mammoet has revealed a new approach to the vital lifting element of wind turbine erection and maintenance.

As a different method with the potential to shake up the industry it heralds a whole new era Mammoet said. The innovation will eliminate the current physical boundaries of turbines and make wind turbine construction and maintenance safer and more efficient, claimed Mammoet.

A pair of new cranes are the basis for this revolution. Both the WTM 100 and WTA 250 use the tower of the wind turbine for support. They will allow components to be both lifted and lowered to and from greater height than current methods, Mammoet said. The new Mammoet system is designed to allow turbine manufacturers to build larger and taller turbines that generate more power.

To improve the efficiency and economic viability of wind energy turbine manufacturers want to make larger and taller turbines, going beyond the capabilities of existing cranes. Mammoet’s solution is a crane for wind turbine assembly and one for wind turbine maintenance. The WTA 250 is for assembling turbines and has a capacity of 250 tonnes. It is under development with engineering company MECAL.

On the WTA 250 a guide rail running along the bottom turbine section allows the crane to lift the next tower section using the turbine’s tower as support. With the next section installed a guide rail is mounted on that and the crane then pushes itself up along the rail. It is a sequence repeated for all remaining sections. On completion the guide rail can be removed and used on another tower or it can be left in place to allow maintenance in future.

The 100 tonne capacity Wind Turbine Maintenance Crane WTM 100 operates in a similar way to its bigger brother. It uses a pair of pre-installed hoisting eyes to pull itself and the load up the turbine tower using it for support. Claws that wrap around the tower are designed to keep the crane steady. In some cases the WTM can be used on existing turbines.

Commenting on the new cranes, Wessel Helmens, Mammoet innovations director, said, “Both cranes are compact – the WTM can easily fit into two standard-sized containers - and the WTA only needs two transport trailers to be moved on site. This makes them easy to mobilise and relocate, and much more efficient than conventional alternatives.”

Helmens continued, “More importantly, both cranes eliminate the height restrictions for turbines and render both the assembly and replacement process faster and more cost-effective.”

A further benefit is that the crane has no footprint and therefore requires no prepared ground, base or reinforcement. In addition, “The tower-based design also puts the crane and the operator closer to the work area, rendering assembly and maintenance both safer and easier,” Helmens said.