De Bilt reports on yet another serious turbine failure. This time the 100m structure folded at a weld line some 30m off the ground. This is of great concern. Whereas most catastrophic failures are due to installation errors at the base bolts, this is a problem with the specification or execution of the construction of the monocoque structure – the main tower.

There’s a fundamental problem here. When steel is welded, the structure of the material either side of the joint, and the weld itself is different to the rolled steel sheet. This inevitably creates a location where stress gets concentrated more as the structure ages.