Laboratory tests aim to improve stability of wind farm cable protection systems

The tests showed that the new C.Shield^® CPS, designed by AIS, significantly outperformed the traditional system in terms of on-bottom-stability during simulated strong offshore currents in HR Wallingford’s purpose-built tank. The new product differs from traditional cable protection systems as it has a significant weight that is embedded into the product and improved outer profile, so that extra stabilisation does not typically need to be added after installation.

“There has been a proliferation of CPS failures, and there are many more wind farms planned which will need cabling to transfer power to onshore substations,” explains Greg Van Hinsbergh, Product Manager for Renewables at AIS. “We are therefore aiming for C.Shield^® CPS design to withstand strong currents, as adding extra stabilisation after installation can of course result in unplanned activities and expenditure.” 
This is the first time that the impact of stormy conditions on existing CPS, which were originally designed for the oil and gas industry, have been tested using physical modelling. HR Wallingford’s Fast Flow Facility allows engineers to simulate storm conditions while onshore. The performance of CPS cannot be easily analysed at sea, as it is not possible to make reliable and cost-effective observations or capture data dynamically during storms. The team conducted tests on a smooth surface and on real scour protection to help simulate the different types of seabed.

“We slowly increased the velocity of the currents, starting from 0m/s, increasing to 2m/s, explained Florine Marias, Project Manager at HR Wallingford. “We used several cameras so that we could observe the exact velocities at which the products started moving. The traditional product started moving at a significantly lower velocity than the C.Shield^® CPS design.”