China’s Deep-Sea Winch System Sets Record at 11,000 Meters

China has achieved a world record with its domestically developed “Haiwei GD11000” full-ocean-depth optical cable winch system, capable of deploying cables to depths exceeding 11,000 meters. The breakthrough, reported by People’s Daily, positions China as the only nation with fully independent intellectual property rights for a full-ocean-depth optical cable winch system, ending decades of reliance on foreign manufacturers.

Context: The Race to the Deepest Oceans

Deep-sea winch systems are the critical infrastructure for ocean exploration, serving as the only passage for equipment to travel to and from the seabed. Until now, this technology was dominated by foreign manufacturers who commanded high prices and restricted access. China’s previous dependence on imported systems left its deep-sea research programs vulnerable to supply constraints and cost inflation.

The Haiwei GD11000 was developed over a decade by a team led by Professor Li Wenhua of Dalian Maritime University’s Marine Engineering College. The system represents the culmination of years of research into materials science, mechanical engineering, and adaptive control systems.

The Aramid Fiber Breakthrough

At the heart of the system’s success is a shift from traditional steel-armored cables to aramid fiber cables. Aramid fiber has a density just one-fifth that of steel while offering far greater tensile strength, reducing cable weight by two-thirds. This weight reduction is critical: as deployment depth increases, the self-weight of steel cables becomes prohibitive.

However, the transition to aramid fiber presented formidable engineering challenges. The material’s high friction coefficient caused inter-layer wear, and its deformation under tension far exceeded that of steel. The team solved these problems through aramid interlayer isolation layers, optimized braiding structures that improved wear resistance by an order of magnitude, and tension-deformation models that redesigned the cable-laying process.

“The alignment direction of every single aramid fiber and the tension of every winding layer were calculated and verified dozens of times,” said Shen Weiwei, Technical Director of Jiangsu Hengtong Huahai Technology Co., one of the industry partners in the project.

The 16-Layer Winding Challenge

Winding 13,000 meters of non-metallic armored optical cable in 16 layers on the winch drum required a self-adaptive cable-laying algorithm that dynamically adjusts servo motor trajectories based on real-time feedback. Any gap between layers would cause deformation transfer to the next layer, potentially ruining the entire spool.

“If there is a gap, the deformation transfers when the next layer is laid, and the entire cable spool is scrapped,” Li Wenhua explained. The team developed precise mathematical models of tension distribution, inter-layer pressure transfer, and fiber alignment to ensure perfect layer alignment.

Testing Under Extreme Conditions

The system underwent rigorous testing before being declared operational. In 2024, land-based testing confirmed 16 layers perfectly aligned on the drum. South China Sea trials aboard the Guangzhou Marine Geological Survey Bureau’s “Haiyang Dizhi 2” vessel followed, where the system achieved a maximum cable deployment of 11,228.7 meters and successfully conducted remotely operated vehicle (ROV) operations for seabed observation, marker placement, and sampling at depths exceeding 4,000 meters.

The most demanding test came in 2025, when the system was deployed aboard the “Xuelong 2” (Snow Dragon 2) icebreaker during China’s 15th Arctic Ocean scientific expedition. For 80 days in polar conditions, the system endured -6°C temperatures, deck icing, icebreaking vibrations, and a Force 9 gale. During one critical moment, two large buoys drifted rapidly toward the ship, forcing Li to make a split-second decision to pay out and recover 200 meters of cable to prevent it from being cut by floating ice.

Breaking the Foreign Monopoly

The Haiwei GD11000 costs one-third less than imported alternatives, and its development has already reshaped the market. “Previously we could only accept foreign pricing. Once we developed it, they lowered prices or even withdrew from the market,” Li Wenhua said. “Only by making it ourselves can we take the initiative.”

The system is part of a family of three winch systems developed by Li’s team: the Haiwei DJ11000 geological winch (the first to break the foreign monopoly), the Haiwei GD11000 optical cable winch (the world’s only full-ocean-depth system of its kind), and the Haiwei CTD11000 trace metal CTD winch (a world first).

Strategic Implications

The achievement extends beyond scientific research. The ability to deploy cables at depths exceeding 11,000 meters opens access to the deepest ocean trenches, including the Mariana Trench’s Challenger Deep. Analysts have noted potential strategic applications, including submarine cable laying in strategic underwater terrain and operations near the “second island chain” — a line of Pacific military bases.

What’s Next

With the Haiwei GD11000 now operational, China’s deep-sea research capabilities have taken a significant leap forward. The system enables routine scientific research at the deepest points of all world oceans, supports ROV operations and seabed sampling at previously impossible depths, and makes deep-sea resource exploration more economically feasible. Questions remain about commercial deployment timelines and whether China will offer deep-sea cable-laying services to other nations, but the technological foundation is now firmly established.