The Vigor Wave Energy Converter concept is based on an array of large, flexible hoses into which pulses of seawater and air are introduced by the action of successive waves. The fluid is forced along the length of each of the hoses by the motion of the waves on its exterior, and the output of the array is connected to a central hub where the driving an electric generator.

With prototype testing about to commence, a crucial issue for the Vigor Wave Energy is to establish and quantify the static and dynamic forces acting on the device’s mooring lines during operation in a range of sea conditions. To achieve this, the company has selected Strainstall Marine subsea load shackles to secure their mooring lines. Shackles are standard equipment for chain and rope assemblies, but the Strainstall Marine subsea load shackle incorporates a load measuring pin in place of the usual solid component. This load cell provides a direct measurement of the force transmitted by the line to which it is attached, and is completely unaffected by the external water pressure that it is subjected to.

“With these results we will be able to say a great deal about the dimensioning, the design and the survivability of the system – based on real data, not just scale tests and theory,” said Vigor Wave Energy Engineer Nicolas Wolf. “Of course this will save us a lot of money in the future, not just through the dimensioning itself, but also by allowing us to focus more on other development issues. The load shackle’s measurements constitute a very direct way for us to move from theory to reality”