28.06.2017

New ideas for wind turbine lifting

International Heavy lift and transport company Mammoet has launched new wind turbine erection and service cranes, the WTM 100 and WTA 250.

Both cranes are tied in to the turbine’s tower which they use as their main support, allowing them to lift and lower components to greater heights. Which it hopes will prove timely with the increasing heights and sizes of wind turbines.

The first new crane, the Wind Turbine Assembly 250 or WTA 250, has a maximum capacity of 250 tonnes and is being developed in close cooperation with engineering company Mecal, which is providing the wind turbine tower design. The tower sections will incorporate a guide rail to which the crane attaches once the first section has been lifted into place on the foundation, allowing it to lift the second section into place, and then climb the tower installing subsequent sections as it goes. Finally it can lift the nacelle and blades into place, before climbing down the tower. Once construction has been completed, the guide rail can either be removed, or remain in place for use on future maintenance operations.
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The Mammoet WTA 250 attaches to the base tower and installs the reast as it climbs its pre-installed track

The second crane is the Wind Turbine Maintenance Crane WTM 100, or simply WTM 100. It has a capacity of 100 tonnes, it attaches to two pre-installed hoisting eyes and can pull itself and the load up the turbine tower. The crane is equipped with claws that wrap around the tower to hold itself in place while lifting. The WTM 100 requires minimal modification to the tower, and as such can be used on existing turbine towers as well as those with pre-installed lifting eyes.
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The 100 tonne WTM 100 pulls itself up on pre-installed lift rings and then clamps to the tower before lifting

Innovations director Wessel Helmens said: “Both cranes are compact – the WTM can easily fit into two standard containers, and the WTA only needs two transport trailers to be delivered to site. This makes them easy to mobilise and relocate, and much more efficient than conventional alternatives. More importantly, both cranes eliminate the height restrictions for turbines and render both the assembly and replacement process faster and more cost effective.”

“Because the cranes are attached to the tower, they have no footprint, making the need for additional ground reinforcements virtually redundant. The tower based design also puts the crane and the operator closer to the work area, rendering assembly and maintenance both safer and easier. Depending on the input from our customers, we may also introduce more additions to the WT-series.”