How subsea cable innovation is supporting offshore wind and deeper-water energy projects

Advancing dynamic cable systems for floating offshore wind

Floating offshore wind is creating a new set of challenges for subsea cable systems, including those associated with projects moving further offshore and into deeper waters.

Floating wind projects require dynamic cable systems capable of moving continuously alongside floating turbines throughout their operational life. This introduces additional complexity around fatigue performance, installation and long-term reliability.

For JDR, one of the key considerations here is approaching floating wind as a complete cable system rather than simply a cable product. Alongside the cable itself, these systems rely on ancillary hardware including buoyancy modules and bend stiffeners that help manage movement and protect the cable during operation.

One of the most common approaches is the “lazy wave” configuration, where buoyancy modules create an S-shaped cable profile in the water. This allows the cable to move more flexibly with the floating platform and reduces excessive tension that could otherwise damage the system.

Designing these systems requires detailed global and local analysis to model turbine movement, fatigue loading and environmental conditions over operational lifetimes that can extend beyond 25 years.

Wet-design cable systems and material innovation

Another major area of focus is the continued development of wet-design cable systems for higher-voltage offshore applications, supporting the evolving requirements of offshore wind, electrification and wider subsea energy infrastructure. Historically, subsea cables relied on lead sheathing to prevent water ingress into cable insulation over long operational periods. While effective, lead increases cable weight and stiffness, creating additional manufacturing, transportation and installation challenges.

Advances in polymer science have enabled the development of water tree retardant XLPE insulation materials that can operate reliably without traditional lead sheathing. This has allowed the industry to move towards lighter, more flexible and more efficient wet-design cable systems.

Crucially, we design such technologies to improve flexibility, pressure performance and reliability across increasingly demanding offshore environments, helping to enable the continued growth of offshore wind, electrification and subsea energy transmission.

JDR is also advancing water and gas blocked cable designs, particularly for low-voltage applications where evolving customer requirements are creating demand for additional protection against water and gas migration. While technically more challenging in smaller conductors, this work has included successful water-blocking tests and the development of designs capable of meeting gas-blocking requirements.

This work is also supported by continued investment into UK manufacturing capability, including JDR’s new high-voltage subsea cable manufacturing facility in Cambois, near Blyth, Northumberland.

Deepwater umbilicals and offshore infrastructure challenges

Beyond offshore wind, oil and gas operators are targeting reservoirs that are more technically challenging to access than many legacy developments. This is driving growing demand for steel tube umbilicals capable of operating reliably over very long distances and at significant water depths.

Thermoplastic hoses remain highly effective for shorter-length umbilicals, while steel tube designs become essential where very long hydraulic transmission distances are required, such as 10, 20 or even 60 kilometres. At the same time, JDR continues to advance thermoplastic hose technology for highly dynamic deepwater applications, including our triple-braid hose design, which combines flexibility with reinforced collapse resistance and has been developed for demanding 3000-metre water-depth environments. In qualification testing, the hose successfully passed impulse testing (widely regarded as one of the industry’s most demanding assessments) without bursting or failing.

Unlike thermoplastic hoses, steel tube umbilicals experience minimal volumetric expansion, allowing hydraulic systems to maintain faster and more predictable response speeds across long-distance subsea applications.

These deeper-water applications also create major engineering challenges. Steel tube umbilicals are significantly heavier than alternative products, increasing tensile loads during both installation and operation. Installation itself can subject products to extremely high crush forces as they pass through tensioning systems aboard offshore installation vessels. To help address these challenges, we have developed a patented ball-and-socket steel tube termination, designed to optimise how load is transferred from the steel tube into the termination.

To support this evolving market, JDR is also developing advanced calculation and analysis tools designed to improve crush resistance, optimise product design and better predict how dynamic systems will behave in offshore environments. We’re also progressing qualification and validation programmes aimed at supporting deeper-water applications approaching 3000 metres.

This includes full-scale qualification and fatigue testing designed to validate long-term product performance before deployment on major offshore projects. These validation programmes are essential for providing JDR customers with the confidence needed to support large-scale commercial deployment in harsh offshore environments.