Slosh Dampers keep windmills at sea stable

For Siemens, we supplied 6,720 so-called slosh damper discs for 140 offshore wind turbines. These are necessary to prevent undesirable vibrations in wind turbines in all weather conditions. These tanks must last for over 30 years and are subject to heavy loads; we took up the challenge and came up with a suitable solution.

The discs have a diameter of 2,240 mm, weigh 50 kilograms a piece and are half-filled with liquid. Six discs are stacked on top of each other and a total of 140 discs are placed per tower. Since a windmill has a lifespan of at least 30 years, we came up with a construction that keeps the discs maintenance-free for the same period of time. As a result, Siemens realises a considerable maintenance cost savings.

Wall thickness of just 4 millimetres  

An additional challenge here is that the top of each disc must be prevented from sinking in because if the liquid touches the top of the disc, the damping effect is reduced. In addition, the bottom disc must be strong enough to carry the other 5 discs including the liquid. Our final design meets all requirements and still has a wall thickness of only 4 millimetres. In addition, we made a secondary containment that functions as a drain pan in case of any leakage.


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