As developers chase stronger flows, onshore wind hub heights are growing beyond the reach of conventional crawler cranes.
Mammoet’s new WTA lifting system allows theoretically infinite hub heights and paves the way towards emissions-free turbine erection.
The WTA assembles wind turbine generators by attaching directly to the tower itself, using a series of clamps to self-assemble and then climb to each lift location. It assembles tower sections, hubs and nacelles, and has a capacity of 150t.
Its innovative concept means that the WTA can keep working when conventional crawler cranes can’t. It operates in wind speeds up to 20m/s, reducing downtime during construction and extending the build season.
As the WTA has a significantly reduced footprint and is much smaller and lighter than any type of crawler crane, it actively lowers the need for groundwork on site. Pads can be smaller, and ground pressure requirements are lessened – maxing out at the 15t/m2 typically needed for assist cranes.
The system’s small size means quicker and more cost-effective mobilization. While a conventional crawler crane can require up to 50 truck loads to reach site, the WTA gets there with just nine.
With no boom laydown requirement, much fewer components and a lower total weight, the WTA is also faster from pad to pad. In fact, relocation time is reduced by approximately 50%, compared to using crawler cranes. It therefore shaves weeks off wind farm construction schedules.
Powered entirely by electricity, it also opens the door for a 100% emissions-free journey from factory to first Megawatt – with transport to site via electric or hydrogen-powered truck, on site maneuvers via ePPU-enhanced SPMT and carbon-free WTA lifting.
The WTA system is now design-ready and can be ready to enter the market during Q2 2023.