Mitsui Engineering has developed a new type of crane that it says can cut on-site assembly times for large wind turbines in half. 

The new crane works by extending with the tower as it grows. As the tower supporting the wind turbine is erected, the hydraulic crane extends in stages up to a height of around 100 metres. Special equipment automatically connects the crane to the tower every 10 to 20 meters to prevent tipping. This setup also allows for a smaller crane with fewer components. As a result, it can be shipped on just five or six trucks, helping reduce assembly costs by more than 10 million yen per turbine. Assembly time is shortened to roughly one week.

Crawler cranes have generally been used to erect wind turbines. This required around 20 trucks to ship crane parts to the site. In addition, crawler cranes are not well suited to work in mountainous regions where wind turbines are often installed.

Mitsui Engineering has confirmed its performance with a smaller prototype. It aims to commercialise the crane in 2013, with an eye toward boosting wind turbine related sales to 10 billion yen in five to six years.