Inspection, Maintenance and Repair (IMR)

Subsea cable reliability for offshore wind and interconnectors

Nexans Inspection Maintenance & Repair service

Under the surface of our seas lies a growing, hidden network powering modern life. Subsea power cables stretch over thousands of kilometers, connecting offshore wind farms to national grids and enabling cross-border energy exchange. These cables are the invisible lifelines of the global energy transition, carrying clean, reliable electricity to homes, industries, and critical infrastructure worldwide.

As dependence on renewable energy grows, the security and resilience of these cables is a top priority for transmission system operators and energy developers. A single cable failure can immediately disrupt offshore wind operations and interconnectors, leading to severe financial and operational consequences. Studies indicate that around 80% of subsea cable outages are caused by external factors, including fishing gear, ship anchors, or natural events such as storms and landslides (ESCA/IMCA, 2025).

Preparedness is therefore critical. With decades of subsea cable expertise, Nexans offers Inspection, Maintenance and Repair (IMR) services designed to reduce downtime, mitigate risks, and protect critical energy infrastructure worldwide.

A growing demand for reliable power transmission

The rapid growth of offshore wind and cross-border interconnectors is reshaping energy systems worldwide. Subsea cables are now essential for transporting renewable electricity efficiently and reliably.

  • Offshore wind capacity is increasing globally, with projects spanning Europe, Asia, and North America (IRENA, 2024).
  • Cross-border interconnectors allow countries to balance supply and demand while integrating renewable energy.
  • The global subsea cable market is expanding to meet growing electricity demand, with networks extending thousands of kilometers.

Cables are often installed in busy maritime areas and harsh environments, exposing them to external damage. Operators require robust strategies to maintain uptime and quickly respond to incidents.

Securing critical power infrastructure

Subsea cables face multiple operational risks that can disrupt power transmission:

  • External threats: anchors, fishing gear, maritime traffic.
  • Natural hazards: seabed movement, storms, landslides.
  • Operational constraints: aging assets, limited repair capacity, and shortages of skilled jointers and marine engineers.

A single cable failure can lead to:

  • Power outages for offshore wind farms and interconnectors.
  • Interruptions in electricity exchange between countries.
  • Significant financial losses, sometimes millions of euros per day (ESCA, 2025).

Downtime without a prepared contingency plan can last up to one year, emphasizing the need for proactive inspection, preventive maintenance, and rapid repair.

Proven performance and global expertise

Nexans brings decades of experience in cable systems and subsea operations, supporting projects across all major offshore regions.

With more than 40 years of subsea repair expertise and over 50 offshore repair joints successfully completed in harsh conditions, Nexans has built a strong track record in maintaining and restoring critical infrastructure. Leveraging a global presence across Europe, Asia, and Africa, the Group is able to respond quickly and efficiently to incidents wherever they occur.

IMR agreements significantly improve operational readiness. With pre-arranged resources and procedures, Nexans can mobilize within 72 hours and reduce response time by up to 70%, helping operators avoid prolonged outages that can otherwise last months.

80%

of outages caused by external factors, highlighting the importance of preparedness (ESCA/IMCA)

Up to

70%

faster response time with IMR agreements

Ensuring subsea cable reliability with Nexans IMR

Nexans delivers a comprehensive Inspection, Maintenance and Repair (IMR) solution designed to ensure the reliability and performance of subsea cable systems supporting offshore wind farms and cross-border interconnectors.

Covering the full lifecycle of cable assets, Nexans IMR combines advanced inspection technologies, preventive maintenance programs, and rapid repair capabilities to reduce risks and minimize downtime. Digital monitoring tools, real-time data analysis, and subsea inspection technologies enable early detection of anomalies, while condition-based maintenance helps preserve asset integrity and prevent unexpected failures.

In the event of an incident, Nexans mobilizes specialized vessels, expert teams, and pre-engineered repair solutions to restore operations quickly. This rapid response is critical for offshore wind connections and interconnectors, where downtime directly affects power transmission, grid stability, and revenues.

With one of the worldโ€™s most advanced cable-laying and repair fleetsโ€”capable of operating at depths of up to 3,000 metersโ€”and continuous investment in innovation, Nexans ensures safe and efficient subsea interventions in even the most demanding environments. Each IMR agreement is tailored to the operatorโ€™s needs, delivering a turnkey solution for subsea cable reliability and resilience.

Inspection: proactive monitoring and asset management

Nexans inspection services focus on early risk detection and asset protection to extend cable lifetime and reduce failure rates: advanced monitoring systems and real-time diagnostics, ubsea cable surveys and condition assessments and asset protection and risk mitigation strategies.

Maintenance: preparedness to minimize downtime

Preventive maintenance is essential to ensure operational readiness and fast intervention in case of failure: pre-engineered repair scenarios tailored to each asset, spare parts management and equipment readiness and dedicated vessel strategy and skilled personnel availability.

Repair: rapid response and efficient restoration

When a subsea cable failure occurs, Nexans ensures fast and effective repair operations to restore power transmission: fault identification and damage containment, rapid mobilization of vessels, equipment, and expert teams and efficient cable repair and system restoration.

Innovation in subsea cable repair

Nexans continues to innovate to improve subsea cable repair efficiency and responsiveness. The upcoming Modular Repair Deck (MRD) is designed for both shallow and offshore operations and enhances global repair readiness.

  • Compatibility with a wide range of vessels, accelerating repair deployment
  • Standardization of mobilization and repair methodology using this state of the art asset
  • Complete vessel mobilization time drastically reduced.

With these advanced IMR solutions, Nexans helps ensure that offshore wind farms and interconnectors remain operational, safeguarding critical energy infrastructure worldwide.

Be prepared for the unexpected

Failures cannot be entirely avoidedโ€”but their impact can be controlled.

By combining anticipation, monitoring, and rapid intervention, Nexans IMR solutions help protect offshore wind investments, secure interconnection capacity between countries, and ensure continuity of power supply.

Anticipate risks. Respond faster. Ensure continuity.

Our success stories

Corfu interconnection repair

Inspection, Maintenance & Repair

Subsea cable replacement in Corfu
Nexans successfully replaced a damaged 145 kV SCFF subsea cable in Corfu for IPTO, showcasing advanced IMR capabilities, offshore expertise, and zero-incident execution.
Ship deck with a crane lifting equipment over the ocean at sunset.

Inspection, Maintenance & Repair

Estlink 2 Subsea Interconnector repair
Nexans completes the rapid repair of the Estlink 2 subsea interconnector between Finland and Estonia, restoring a critical 650 MW power link with advanced IMR expertise.

Frequently asked questions

Service

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Subsea cable Inspection, Maintenance & Repair (IMR)

Service

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Subsea cable Inspection, Maintenance & Repair (IMR)

Innovation

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Nexans Modular Repair Deck

Testimonial

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Estlink 2 testimonial of Timo Kiiveri, EVP of Fingrid

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Protecting subsea and land cables with Nexans IMR