HEBETEC Engineering SA developed a modular structure for assembling prefabricated concrete wind turbine towers. INGPHI SA designed and performed the static verification of this structure.

A wind turbine tower has a total height of 120 m (394 ft.). It has a tubular section and consists of prefabricated sections that are 10 m (33 ft.) to 16 m (53 ft.) long. The sections are assembled from the base of the tower using an assembly structure that is equipped with a mobile lifting system.

The assembly structure consists of metal frames that rest on the future foundation of the wind turbine tower. It is stabilized using lateral cables to reduce the tensile force in the foundation during lifting operations.

In the center of the structure, a movable frame serves as a guide when lifting concrete tower segments. The frame is attached to the tower section and the whole assembly is then lifted using cables and actuators attached to the top of the assembly structure. Once the lifting operation has been completed, the next concrete section is slid into the center of the assembly structure and attached to the underside of the previous segment. The moving frame is then released and lowered to proceed with the next lifting step.

The system developed makes it possible to build a wind turbine tower without a crane.