HighStep for electricity pylons
The requirements of wind power plants
The requirements of wind power plants for the HighStep System
Requirements on the climbing system
Wind energy suppliers represent a central client segment at HighStep Systems AG. The HighStep System will meet today's as well as tomorrow's requirements put on a climbing system by operators of wind power plants.
Requirements from a operator of existing wind power plants perspective
Every wind power plant has a secured ladder so, from the point of view of occupational safety, there is no need to retrofit with a significantly safer system. Ergonomic climbing has long been a desirable criterion, but this is not usually by itself sufficient to persuade operators, service companies and plant manufacturers to retrofit with a manual mechanical climbing system.
The decisive added value lies in reaching the nacelle comfortably by lift, instead of having to climb oneself.
Nowadays, lifts have long been standard in two or three storey buildings. No one wants to do without this easy way of reaching upper floors. But why did not that also apply for so long to wind power plants, which are much higher? 50, 60 and 80 metre towers have been built without being equipped with a convenient means of access. Instead, one relied on the conventional, totally inconvenient ladder. Everyone had to take this strenuous access route to reach the nacelle.
- The existing ladder should remain usable for manual climbing
- The investment must be in proportion to the benefit. The direct, measurable benefit is the profit made by the wind power plant.
- The retrofitting has to be easy and inexpensive
- Existing processes, such as rescue in emergencies, must not be changed
- The use of additional equipment should not increase maintenance expenditure
Requirements from a constructor of new wind power plants perspective
Modern wind power plants have hub heights of 150 metres or more. During the construction of the towers, the erectors have to climb to the actual highest point to perform their tasks, such as bolting tower segments together. Conventional systems only allow the erectors to climb up using their own muscle power, so they have to climb up to an ever increasing height several times a day.
The first case concerns hybrid towers, the first 80 metres of which are concrete. Such towers take up to 9 weeks to construct, during which time the concrete segments are cast on-site. The tower grows a little each day. The steadily increasing height of the tower makes it impossible to use a conventional lift operated via rope hoists. Instead, a swaying work platform is hoisted via a motorised rope winch. On arriving at the top, the erector has to use a ladder to reach the work platform. All in all it is a very unsafe solution.
The second case relates to the construction of full-section steel tube towers, which are delivered at the height of the flange without platforms. During construction, the platform provides a standing area from which each bolt of the flange can be reached. If there is no platform, several ladders have to be extended up the tower so that the erector can reach all the bolting points at the top end of the tower. Here again, climbing has to be done manually, it is impossible to use conventional service lifts.