In the evolving world of subsea cable protection, material choice is critical. At Vos Prodect, we have for years advocated and delivered cast iron joint bend restrictors for critical cable repair and protection applications. Below we explain why cast iron offers superior performance and reliability compared to polyurethane alternatives.

Material Consistency, Quality Assurance and Reliability

Polyurethane systems rely on precise chemical recipes and mixing protocols. Even small deviations in the formulation or curing process can lead to inconsistent properties, defects, or early degradation.

By contrast, cast iron is a well-established engineering material whose composition and casting processes are highly controlled. Defects (such as cracks, porosity etc) are easier to detect and mitigate.

For Vos Prodect, this means that the quality control on all materials needs to be robust.

Thermal Dissipation & Cable Insulation Considerations

Polyurethane by its nature is an insulating material. When installed tightly around a live cable, it may inhibit the cable’s ability to shed heat into the surrounding environment. Over time, heat can accumulate, negatively affecting cable performance.

Cast iron, being metallic, provides better conduction and passive heat dissipation, helping to maintain temperature balance along the cable sheath.

Load & Bending Performance with Compact Design

To match the bending moment and load capacity of a cast iron restrictor, an equivalent polyurethane design would generally need to be significantly bulkier (thicker walls, larger dimensions).

Cast iron’s higher strength and stiffness allow it to handle more aggressive bending moments in a more compact form factor, which is beneficial in tight subsea installations. Also during offshore cable repair campaigns, Vos Prodect’s engineered cast iron joint bend restrictors offer a major operational benefit. The engineered system do not require a spreader beam or measured chains to support the lifting and lowering of the cable during offshore operations. This assists in simplifying handling, increasing installation speed and reducing offshore vessel costs.

Long-Term Durability and Storage

Polyurethane degrades over time. We have observed that repair kits and spare polyurethane components stored in warehouses for prolonged periods may exhibit compromised mechanical properties.

Cast iron, on the other hand, does not suffer such degradation in typical warehouse conditions and can be stored for years with minimal performance loss, ideal for long lead time projects or spares.

This robustness reduces the risk of standby or stock spare failure when it matters most.

Proven Track Record & Stability on the Seabed

Vos Prodect has deployed cast iron joint bend restrictors in many cable repair and protection campaigns for more than 20 years. They are field proven and integrated into our repair system offerings.

Cast iron’s heavier density also contributes to seabed stability, resisting movement or shifting caused by currents, which is especially important in free-span zones. By contrast, polyurethane designs, while typically bulkier to achieve similar load capacity, also tend to be more buoyant, which can introduce undesired lift and movement in free-span areas during offshore operations and lifetime of the asset.

Conclusion

In summary, for submarine cable protection and repair applications, cast iron joint bend restrictors offer a more reliable, durable and performance oriented solution compared to polyurethane. Their advantages in quality assurance, thermal dissipation, load capacity, long-term storage and seabed stability make them an optimal choice for challenging offshore projects.

At Vos Prodect, we continue to refine our cast iron designs to accommodate a wide range of bending moments, from array cable repair scopes to export cable repairs, ensuring that clients receive dependable, long-lasting protection in their most demanding environments.

Two years ago, Van Oord approached us with a challenging request, to design and deliver a bespoke cable protection system for HDD pipe cable landing, to support their cable installation operations in a challenging and demanding environment.

Our team successfully designed, tested and delivered the solution in just 8 weeks!

The installation went smoothly and the project team was very satisfied with the system’s performance.

Fast forward to last year Van Oord returned with a follow-up project, featuring new requirements and even tighter constraints. Leveraging the valuable feedback from the first campaign, we developed an improved CPS that exceeded expectations once again.

Feedback from the project team upon completion of the project:

“The cable installation campaign went very well. The CPS performed excellently and overall we have had a very good experience with your product. It was also nice to have a more lightweight bend restrictor for this project.”

Whether it’s developing a brand new solution or supporting fast paced project timelines, we are always ready to rise to the challenge and deliver reliable, high-performance systems that go beyond expectations.

At first glance, you might think these are canned sardines. But looks can be deceiving these are cast iron shells, a vital solution protecting subsea cables around the world from nature’s forces and human activities.

What Are Cast Iron Shells?

Cast iron shells (also known as split pipe castings, half shells, or articulated pipe sections) are robust, segmented pipe structures made from cast or ductile iron. They are clamped around subsea cables to provide:

• Mechanical protection against fishing gear, anchors, rocks, and dropped objects.
• Abrasion resistance on rocky seabeds and shore crossings.
• Weight and stability, ensuring cables sink and remain securely on the seabed.
• Controlled bending radius, safeguarding the cable’s MBR during and after installation.

With over 20 years of expertise in designing and supplying these systems, Vos Prodect is a trusted partner for subsea projects worldwide.

Typical Applications

Cast iron shells are used in critical zones where subsea cables require extra protection, such as:

• Shore-end protection: where cables exit onto the beach or enter the sea, exposed to waves and human activity.
• Cable crossings: when a new cable crosses existing pipelines or other cables.
• Rocky seabeds: preventing damage from sharp terrain and abrasion.
• Burial transitions: where a buried cable transitions to surface laying on the seabed.
• Emergency repair kits: engineered systems for safeguarding cable repair joints.
• Offshore construction: securing cable entry points and protecting free spans.

Innovation and Reliability

Whether for an offshore wind farm, telecom network, or energy project, Vos Prodect delivers solutions designed to withstand the harshest environments. Every cast iron shell is engineered with durability, efficiency, and reliability in mind, ensuring subsea cables remain safe and operational throughout the project’s lifetime.

Learn more about how Vos Prodect protects subsea cables worldwide at www.vos-prodect.com.

Introducing the new options for our market leading Cable Hang‑Off System

A Cable Hang‑Off System is a critical interface used in offshore wind, oil & gas and marine power installations. It serves two key functions:

• Mechanical support to secure heavy subsea cables within foundation entry tubes (for example monopiles, jackets, J‑tubes).
• Sealing to prevent moisture, gases or airflow from entering the working deck, compromising internal structures or causing corrosion.

Historically, resin filled seals have been the standard approach for installing Cable Hang-Off systems, valued for their track record of reliability. However, with evolving foundation and turbine designs offering improved access and internal ventilation, there has been a growing demand across the market for resin free cable hang-off solutions as a viable and forward looking alternative.

Our Resin‑Free Sealing Solutions

Vos Prodect offers two proven alternatives to conventional resin filled systems. Both solutions are fully resin free and tailored to today’s sustainability, safety and efficiency standards.

Environmental Seal (Complying with IP44)

This system provides a weather protected seal conforming to the IP44 standard, offering protection from splashing water and solid particles from any direction. It is suitable for foundation designs with adequate internal ventilation and has seen successful deployment on numerous projects across Europe and North America.

The environmental seal requires no resin and is quick and straightforward to install. It uses a combination of robust mechanical clamping and elastic interfaces to achieve reliable sealing without the need for resin.

Dry Seal (Pressure Tight Resin Free Solution)

The dry seal represents a progression in the hang-off system design, offering pressure-tight performance for demanding offshore environments and all without the need for resin. This solution ensures a secure seal using finely machined metal fittings, gaskets and flanges, offering structural and environmental protection without the use of resin.

This system has been developed in collaboration with offshore developers seeking a pressure tight, clean, efficient and compliant alternative to traditional resin sealing methods.

Conclusion

With over 20 years of experience in designing, building and testing subsea cable hang-off systems, Vos Prodect has developed resin-free solutions that deliver uncompromising integrity and long term performance. These innovations are engineered to maintain the full design lifetime of your project while simplifying installation, improving operational efficiency and reducing environmental impact.

Whether you require the environmental seal for ventilation scenarios or a pressure tight dry seal for demanding applications, Vos Prodect has the expertise and proven history to deliver.

Get in touch to learn how Vos Prodect can help optimise your cable protection approach and align with your sustainability and performance goals.

Keeping Up with Industry Growth

As offshore wind farms expand in size, depth, and complexity, the engineering challenges surrounding subsea cable installations continue to evolve. With cable diameters increasing, higher project loads and installations reaching greater water depths, the demand for stronger, more reliable cable hang-off systems has never been greater.

At Vos Prodect, we are committed to engineering excellence and continuously evolving to meet these growing demands. A key part of ensuring the reliability of cable hang-offs is conducting design verification tests, which validate their performance under real-world offshore conditions.

With an increasing number of projects requiring cable specific verification tests, from temporary hang-off section tests to final cable hang-off armor wire clamp tests, we have taken proactive steps to expand our testing capabilities.

Introducing the New Vos Prodect Testing Tower

To accommodate the increasing demand for design verification testing, we have constructed an additional testing tower at our facility in the Netherlands. This new infrastructure allows us to:

• Expand our testing capacity to meet growing industry needs
• Accommodate larger cable diameters and higher load demands
• Perform both temporary and final cable hang-off tests under extreme conditions
• Validate our engineered solutions for deeper water installations

The ability to rigorously test cable hang-offs before offshore deployment is critical in optimising installation efficiency and minimising costly vessel time offshore. By verifying load performance in a controlled environment, we provide project teams with the confidence that Vos Prodect cable hang-offs are ready for offshore conditions.

Engineering Solutions That Drive Offshore Success

As the offshore wind industry continues to push boundaries, we at Vos Prodect remain dedicated to providing innovative, high-quality subsea solutions. Our expanded testing capabilities reinforce our commitment to ensuring that every cable hang-off system we engineer meets the highest performance and safety standards.

With the new testing tower now operational, we are ready to support upcoming projects worldwide, delivering tailored cable protection and hang-off solutions that withstand the challenges of modern offshore installations.

For more information about our enhanced testing capabilities or to discuss your upcoming offshore project requirements, contact us today!

The Dutch have a long-standing tradition of engineering excellence, marked by innovation and reliability. This tradition is beautifully exemplified by the iconic Queen Emma Bridge, also known as Pondjesbrug, in Willemstad, Curaçao, which has stood the test of time as a testament to Dutch engineering prowess.

Pondjesbrug: A Masterpiece of Dutch Engineering

The Queen Emma Bridge, famously known as the “Swinging Old Lady,” is a floating bridge that connects the two sides of St. Anna Bay in Willemstad, Curaçao. What sets this bridge apart is its unique design. In an era where swing bridges are a rarity, the Queen Emma Bridge is an engineering marvel that has been swinging open and closed for nearly 250 years. This bridge stands as a shining example of Dutch engineers’ ability to provide cost-effective and reliable solutions.

Innovation Meets Reliability

The Queen Emma Bridge remains a unique solution for the residents and visitors of Willemstad. It continues to be the best solution for the city’s transportation needs. But the story doesn’t end there. Dutch engineers continuously upgrade the bridge’s design to ensure it remains effective and functional. It’s a testament to the Dutch commitment to embracing innovation without sacrificing reliability.

Dutch Pioneers in the Offshore Market

Dutch engineers have always been at the forefront of offshore development. The Netherlands, a country with a rich maritime history, is a leader in offshore technology. From offshore oil and gas to the rapidly growing offshore wind sector, Dutch expertise is highly regarded worldwide.

Vos Prodect: Continuing the Tradition of Dutch Engineering

In the offshore wind industry, Vos Prodect’s Dutch engineering team proudly carries forward this tradition. With over 25 years of experience, we have developed a cable hang-off system that remains one of the most reliable, cost-effective, and innovative solutions in the market. Our commitment to excellence is unwavering.

The Future of Offshore Engineering

The future holds more exciting developments. Vos Prodect’s engineering team is hard at work, and we’re thrilled to announce the upcoming 3.2 version of our cable hang-off system. This new innovation is a testament to the Dutch spirit of pushing boundaries, embracing innovation, and delivering excellence.

 In conclusion, Dutch engineering, from the Queen Emma Bridge to offshore wind solutions, stands as a beacon of innovation and reliability. The Dutch tradition of finding cost-effective, yet highly effective solutions lives on, and Vos Prodect is proud to be a part of this enduring legacy.

Watch this space for the latest developments in offshore engineering from Vos Prodect. The best is yet to come!

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