Cable Laying Vessels: Engineering Marvels Powering Global Connectivity

Beneath the ocean’s surface lies a hidden network of cables—thousands of miles of fiber-optic threads and power lines that keep our digital world connected and our green energy flowing. But who installs these underwater lifelines? Enter cable laying vessels (CLVs)—floating engineering marvels equipped with space-age propulsion, robotic submarines, and enough cable to wrap around the Earth. This article dives into how these high-tech ships work, from their hybrid-electric engines to their AI-assisted positioning systems, and explores why they’re becoming the unsung heroes of both the internet age and the renewable energy revolution. Want to know how a single ship can lay a cable across an ocean while battling storms and sea currents? Read on!

The Critical Role of Cable Laying Vessels in Modern Infrastructure

Cable laying vessels (CLVs) serve as the unsung heroes of global communications and renewable energy infrastructure. These highly specialized ships perform the complex task of installing and maintaining submarine fiber-optic cables that carry over 99% of international data traffic, enabling everything from financial transactions to global video conferencing. Beyond telecommunications, modern CLVs also deploy high-voltage power cables connecting offshore wind farms to mainland grids, forming the backbone of the green energy revolution.

The operation of these vessels requires extraordinary precision, as they must handle cables that can stretch thousands of kilometers while weighing hundreds of tons per kilometer. Advanced CLVs like Prysmian’s Leonardo da Vinci or NKT’s NKT Victoria incorporate massive cable carousels capable of holding up to 10,000 tonnes of cable, along with sophisticated cable laying equipment that can bury cables up to 3 meters deep in the seabed for protection. These vessels often operate in challenging marine environments where they must maintain exact positioning for days or weeks at a time while laying cable at precise speeds and tensions.

Advanced Propulsion Systems Enabling Precision Operations

Modern cable laying vessels predominantly utilize diesel-electric propulsion systems, which have become the industry standard due to their flexibility and efficiency. In this configuration, multiple diesel generators produce electricity that powers electric motors connected to azimuth thrusters. This setup allows for optimal engine loading regardless of speed requirements, significantly improving fuel efficiency compared to traditional direct-drive systems. The electric propulsion also enables precise speed control crucial for cable laying operations, where maintaining exact tensions and laying speeds is paramount.

The transition to more environmentally friendly solutions has led to the development of hybrid propulsion systems incorporating large battery banks. Vessels like NKT’s NKT Victoria feature massive 6 MWh battery systems that allow for peak shaving – supplementing the diesel generators during high-power operations and storing excess energy during low-demand periods. These batteries also enable fully electric, zero-emission operations during sensitive environmental operations or when working near marine protected areas. Some newer vessels are taking this a step further with LNG-powered systems, such as Prysmian’s Leonardo da Vinci, which reduces CO₂ emissions by 20-25% compared to conventional diesel systems while completely eliminating sulfur oxide emissions.

Maneuverability and Positioning: The Technology Behind Precise Operations

The unique operational requirements of cable laying demand exceptional maneuverability and station-keeping abilities. Modern CLVs achieve this through sophisticated dynamic positioning (DP) systems, typically DP2 or DP3 class, which use a combination of GPS, motion sensors, and computer-controlled thrusters to maintain position without anchoring. These systems constantly analyze environmental factors like wind, waves, and currents, automatically adjusting multiple azimuth thrusters – some capable of 360-degree rotation – to counteract any drift.

Many advanced CLVs feature a combination of main azimuth thrusters and tunnel thrusters at the bow and stern for enhanced maneuverability. The Nexans Aurora, for instance, utilizes a unique thruster configuration that includes two 3,000 kW main azimuth thrusters and three 1,500 kW tunnel thrusters, allowing it to maintain position in severe weather conditions while laying cable with millimeter precision. Some vessels also incorporate heave compensation systems that counteract wave motion, ensuring constant tension on the cable being laid even in rough seas.

Recent Developments

Teerprop Selected to Power the World’s Largest Cable-Laying Vessel

In a landmark deal for maritime engineering, Teerprop has been chosen to supply the integrated propulsion system for Fleeming Jenkin—set to become the world’s largest cable-laying vessel (CLV) upon delivery in 2026. This cutting-edge CLV, designed to handle the growing demands of intercontinental data cables and offshore wind farm connections, will feature Teerprop’s hybrid-electric propulsion technology, combining diesel generators with battery banks for unmatched efficiency and precision. The system’s optimized power distribution will enable the vessel to operate in zero-emission mode during sensitive operations while maintaining the thrust needed for deep-sea cable deployment.

Teerprop’s solution includes azimuth thrusters with dynamic positioning (DP3 class), ensuring the 180-meter vessel can hold station flawlessly even in rough seas. The propulsion package also incorporates AI-driven energy management to balance power between generators, batteries, and thrusters—critical for long-duration cable-laying missions. With a cable capacity exceeding 10,000 tonnes, Fleeming Jenkin will tackle projects like transatlantic fiber-optic links and high-voltage offshore wind interconnectors, setting a new benchmark for CLV capabilities. This collaboration underscores how specialized propulsion systems are becoming the beating heart of next-gen maritime infrastructure.

Future Trends and Technological Advancements

The cable laying industry faces several emerging challenges that are driving innovation in vessel design. Environmental regulations, particularly the IMO’s push for zero-emission shipping by 2050, are accelerating development of alternative propulsion systems. Several manufacturers are exploring ammonia or hydrogen-powered CLVs, while others are developing fully electric vessels with massive battery capacities for short-range operations supplemented by onboard generators for transits.

Another significant trend is the increasing size and capacity of CLVs to handle next-generation cables. New offshore wind farms require cables with higher voltage ratings (up to 525 kV) and greater diameters, necessitating vessels with larger carousels and more powerful laying equipment. The industry is also seeing increased automation, with some new designs incorporating AI-assisted route planning systems that can optimize cable laying paths based on seabed surveys and weather forecasts. Looking further ahead, concepts for autonomous or remotely operated cable laying vessels are beginning to emerge, potentially revolutionizing the industry by enabling operations in hazardous or remote areas without risking crew safety.

These technological advancements ensure that cable laying vessels will continue to play a vital role in global infrastructure development, adapting to meet the growing demands of digital connectivity and renewable energy expansion while addressing environmental concerns and operational challenges in an increasingly complex marine environment.