Submarine Power Cables: What Happens to Out of Service Cables and How They're Maintained

Underwater communication and power transmission networks are essential for modern global connectivity. Submarine power cables, in particular, form a crucial part of these networks. However, when these cables fail or become out of service, what happens to them? How are they repaired, and what happens to cables that are no longer in use? This article delves into the complexities of submarine cables and provides insights into the maintenance and disposal processes.

Introduction to Submarine Power Cables

Submarine power cables are long-distance undersea electrical cables that transmit power across oceans. These cables are typically buried in the seabed, where they can face extreme pressures and harsh environmental conditions. The process of laying and maintaining these cables is challenging and often expensive, which means that once a cable is out of service, the options available for disposal or repair are limited.

The Complexity of Repairing Submarine Cables

Repairing a broken submarine cable is an exceedingly complex and technically challenging task. Imagine trying to locate a 10 cm diameter cable buried under hundreds or even thousands of meters of water in the vast ocean. Even identifying the breaking point of the optical cable can be a daunting task. Once the breaking point is found, it must be salvaged, and the repair process must be carried out. For these reasons, the technical difficulty involved in repairing submarine cables is immense.

What Happens to Out of Service Submarine Power Cables?

When submarine power cables become out of service, the first course of action is often to determine if they can be repaired. However, due to the high cost and technical challenges associated with repair, many cables are left on the seabed. Nautical charts typically mark the locations of these cables in shallower waters, where they are less likely to be a risk to navigation.

Especially in areas where sailors might otherwise anchor, these cables are marked to avoid accidental damage. In some cases, the cables are annotated as abandoned, reflecting the fact that removing them would be far more expensive than the scrap value they would generate. The economic cost of removal, combined with the potential environmental impact, makes it a non-viable option for most abandoned cables.

Environmental Impact and Disposal Concerns

The potential environmental impact of abandoned submarine cables is a critical concern. These cables can take many forms, such as steel-armored cables, which can cause harm to marine life when they rust and break apart. Additionally, the materials used in the cables, such as copper and aluminum, pose disposal challenges. Various recycling methods have been developed to ensure that these materials can be reused or disposed of in an environmentally responsible manner.

Efforts are under way to develop sustainable solutions for the disposal and management of abandoned submarine cables. These include methods such as deep-sea disposal, where the cables are buried in the deep ocean, as well as recycling and repurposing initiatives. While deep-sea disposal is seen as a less harmful option, recycling programs offer a more sustainable solution by recovering valuable materials and reducing waste.

Conclusion

Submarine power cables are vital components of global power transmission networks, and their maintenance and management are complex and demanding tasks. Out of service cables, while often left on the seabed due to the high costs and technical difficulties of repair, have their disposal and management carefully considered to minimize environmental impact. The ongoing development of sustainable practices and technologies aims to ensure that these cables can be managed responsibly in the future.