Sea Technology

JUL 2017

The industry's recognized authority for design, engineering and application of equipment and services in the global ocean community

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Page 12 of 68

12 st / July 2017 volved rethinking a number of design features. One of the main challenges was to stop being so conservative in the design process. After analysis, it was decided that the cables did not need to be so large and the wall thickness of the polymer used could be reduced and still meet the requirements. An- other modification was ensuring that the cable protection material could manage the increased amount of heat generated by power cables. Working shoulder-to-shoulder with customers' engineering teams, Trelle- borg was able to address other issues that were important in reducing instal- lation time and costs. By listening to customers' needs, the product devel- opment team designed an innovative protection system so that cable protec- tion could be installed, removed and reused without the use of an ROV or diver intervention. This specific design improves safety and reduces instal- lation complexity. The cutting-edge solution also permits both monopile and J-tube installation for wind turbine generators and offshore substation plat- forms without procedural variation. Manufactured from API 17L-certified Uraduct material for both internal and external components, the integrated cable protection system has very high impact and abrasion resistance. It is also designed with a smooth outer surface that reduces drag and snagging risks, further stream- lining the installation process. The system re- quires minimal assembly, is easily ex- tendable and can be manufactured to meet any diameter wind farm power cable. By rethinking the design to meet the requirements needed for wind farm power cables, Trelleborg was able to successfully overcome the design chal- lenges, and the protection system is now ready for rollout on offshore wind projects. Verification Testing Trelleborg successfully completed a series of wet tests in November and December 2016 to verify the capabili- ties and functionality of its NjordGuard cable protection system for installation and removal on J-tube and monopile interfaces for offshore wind farms. The testing took place at the Off- shore Renewable Energy (ORE) Cata- pult's National Renewable Energy Centre, the U.K.'s flagship technology innovation and research center for off- shore wind, wave and tidal energy. Trelleborg was able to perform eight full-scale wet tests of NjordGuard us- ing ORE Catapult's controlled open- access shallow-water testing environ- ment facility located in Blyth, England, covering a range of installation sce- narios without having to go offshore. In addition to passing all the tests, the cable protection system was installed and removed from the test rig without use of an ROV. The successful tests definitively prove NjordGuard is capable of instal- lation into both monopile and J-tube openings and can be successfully re- moved without the need for ROVs. The test results provide a greater under- standing of potential installation issues customers might face, such as pull-in and pull-out loads. We also gained valuable insights into the dynamics of the system to help further refine and optimize our designs to optimize per- formance for our customers' critical applications. Currently available to the market for both array and export cables, further testing of NjordGuard will be an in- tegral part of developing and enhanc- ing the solution to meet our customer needs and further highlights our com- mitment to supporting renewable en- ergy projects. "It is essential for companies to be able to test their products in a con- trolled environment, allowing input into the design and installation proce- dures at an early stage," said Stephen Robertson, head of business develop- ment for ORE Catapult. "Our marine and subsea renewable testing facilities provide an excellent Subsea view of NjordGuard at power cable exit point.

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