Raising and lowering the tower

We believe it is essential to have a safe and simple way of raising and lowering the wind turbine. There are various systems used, the most popular one being to have an anchor point and winch using a “gin pole”. This requires an extra cubic meter of concrete for the anchor, and a fair bit of work with a tirfor winch.

We have seen other turbines that were lifted with a crane (OK first time, but what about the maintenance costs?) and in some cases turbines that had to be serviced by working aloft – again, reducing the cost of the hardware, but increasing the cost of maintenace.

The most dangerous suggestion we have seen is using a gin pole and attaching it to a car or tractor. The traction between tyres and grass is far too variable, and the forces are colossil when the turbine is nearly horizontal.

We are using a hydraulic ram and mobile hydraulic power pack to raise and lower our towers. This is simple and effective and the tower can be down within about ten minutes of arriving on-site. This method is used by many lampost companies to raise and lower their towers and works perfectly well.

The maximum load is when the tower is nearly horizontal, but the interesting part is when the tower is near vertical. At a certain point, it becomes almost balanced and you could push it into place with your little finger. Because there is a small amount of play in the hinge and at the connections for the hydraulics, this allows the turbine to swing by quite a few degrees at this point.

This is a problem for all lifting systems, particularly if you are behind the tower working a winch. At that point, the tower could swing like a pendulum and if any component failed, it would come down on top of you. Your hard hat would extend your lifespan by milliseconds….

While our hydraulic system can be operated remotely for safety reasons, we prefer not to allow the turbine to swing freely. To prevent this, we attach a rope about 3m from the base and a second person keeps this tight to take up the slack when the turbine is close to vertical. This way, the turbine falls gently onto its base and can be bolted down once in place.

This system is safe, simple and enable easy maintenance. For DIY enthusiasts, it would be possible to purchase a suitable hydraulc ram and operate this using a hydraulic take off from a tractor.