Dynamic cable tests conducted by CRP Subsea and Hellenic Cables at the University of Exeter, U.K., included individual evaluations of power cable alone and power cable with bend stiffener to compare performance and fatigue. When tested with a CRP subsea bend stiffener the power cable survived 3.7 times as many cycles and was on average 72.5% stiffer than the power cable alone.

These findings underscore the importance of a bend stiffener in extending the fatigue life of equipment to be used in future floating offshore wind applications. Bend stiffeners protect flexible pipes and subsea cables from overbending in fixed and floating offshore wind farms. The elastomeric material from which they are manufactured makes them suited to the constant wave- and current-induced motion of dynamic installations. Thanks to their conical shape, these components gradually increase the overall stiffness of a pipe or cable, preventing overbending at the termination point.

The performance characterization testing entailed bending the cable to a 3.7° angle at the headstock while holding a constant force of 40, 60 and 80 kilonewtons (kN) at the tailstock over a 10 second cycle period. During the fatigue testing, the cable was bent to 4° while holding a constant force of 80 kN. The cycle period was steadily decreased from 10 seconds to 1 second to minimize the overall test duration.

The collaborative project is part of the EU-funded MaRINET2 program.

To contact the author of this article, email shimmelstein@globalspec.com