Faster workplace operations with pre-assembled anchor cages
More and more foundation builders are discovering the benefits of Proplate’s solutions for wind turbine foundations. Kanonaden Entreprenad is one of the companies that used the new concept with pre-assembled anchor cages.
We met with Magnus Gustafsson, Concrete Are Business Manager at Kanonaden’s headquarters in Nässjö, Småland.
“Wind energy is an important area for Kanonaden Entreprenad”, he explained. “The segment accounts for about 30% of our total business. Other areas we are involved in are construction and earthworks, district heating plants, cable laying and mining.”
Higher towers make higher demands on foundations
The trend in wind energy is toward ever-higher towers. It is difficult to obtain cost efficiency in the lower towers, and according to Gustafsson they need to come up to 200 meters to get good wind. And the higher the towers, the greater the demands on the foundations.
Then what are anchor cages for? For those who are not familiar with how a wind turbine is set up, the anchor cage is a relatively unknown part of the design. Those responsible for foundation work and for the long-term stability of wind turbine installations see it differently, however.
“The anchor cage is crucial, since it holds everything together. Quality-wise, it is the most important part of the foundation”, said Gustafsson. The wind turbine installation is anchored in the anchor cage. It sits under the tower, cast in concrete, and it is extremely important that it be of the proper height and diameter.
If the anchor cage is a critical part, so is the “template”, i.e., the ring at the top of the basket, which requires the highest tolerances because it is important that the bolts fit exactly into the holes on the tower mount. The tolerance on the cage is only +/- 1 mm at the top.
New challenges require new solutions
As an actor in the wind energy industry, one must continually develop and find new markets, as well as suppliers and solutions.
“It’s a matter of finding those who are good at what they do”, said Gustafsson. “Those who have modern machines and skills to ensure that things are correct, for example. In addition, businesses that handle large volumes of plate often have good relationships with sheet metal suppliers and thus get better prices.”
The primary challenges for the construction company are the soil and groundwater, which can affect the work. Gustafsson noted that foundation work in itself is not complicated, but it takes two to three weeks for five or six people to finish it. He added that “the advantage of pre-assembled anchor cages is naturally that the on-site process goes more quickly”, also citing Proplate’s rapid service and flexibility.