Deep-Sea Thrusters: The Wisdom of Power Selection Behind Scenarios

The mission scenarios of deep-sea exploration vary greatly: some require precise hovering and sampling at the 10,000-meter seabed, some need efficient operations in deep-sea mining areas, and others demand flexible navigation in coral reef zones — different tasks have distinctly different requirements for power. As a "customized power solution," the core appeal of deep-sea thrusters lies in the "precise matching between power type and scenario needs." From electric to hydraulic, and then to jet propulsion, each power form has its exclusive "deep-sea stage," behind which is engineers' in-depth analysis of task requirements and technical trade-offs.

Electric thrusters are the "main pioneers" of deep-sea scientific research. With the characteristics of "low noise, high efficiency, and precise controllability," they have become the first choice for scientific research submersibles. Powered by batteries, they drive propellers through brushless motors, generating extremely low noise during operation. This minimizes interference with deep-sea organisms and avoids disrupting the submersibles' acoustic detection equipment. Meanwhile, the thrust adjustment precision of electric thrusters can reach the millinewton level. Equipped with a multi-thruster coordinated control system, they can achieve refined movements such as centimeter-level hovering and in-place steering — which is crucial for tasks like deep-sea organism observation and seabed geological sample collection. China's "Jiaolong" manned submersible is equipped with high-power electric thrusters. During the biodiversity survey at Caiwei Seamount in the Western Pacific, it could quietly follow deep-sea fish schools and capture precious image data; the "Haidou-1" full-ocean-depth unmanned submersible, relying on the high efficiency and energy-saving features of electric thrusters, achieved cruise detection for several hours at the 10,000-meter seabed.

Hydraulic thrusters are the "powerhouses" for deep-sea heavy-duty operations. Focusing on "high thrust and impact resistance," they are designed specifically for high-intensity tasks. Unlike electric thrusters, they drive piston pumps through high-pressure hydraulic oil, converting hydraulic energy into mechanical energy. Their thrust can be several times or even dozens of times that of electric thrusters, and they can operate stably in environments with strong impacts and high loads. These characteristics make them the core power for heavy-duty operation equipment such as deep-sea mining, seabed pipeline laying, and sunken ship salvage. For example, deep-sea mining robots need to excavate ore on the seabed and transport it to the sea surface. Their propulsion systems not only have to overcome the huge resistance after ore loading but also cope with impact of the seabed terrain. Hydraulic thrusters can output high thrust instantly to ensure the robots do not deviate or get stuck; in seabed pipeline maintenance tasks, operation robots driven by hydraulic thrusters can firmly "grasp" the pipelines and complete high-intensity operations such as welding and component replacement in strong ocean current environments. Their impact resistance and load-carrying capacity are irreplaceable by electric thrusters.

Jet thrusters are the "agile experts" for operations in complex terrains. With the advantages of "propeller-free design and anti-entanglement," they solve the problem of operations in obstacle-rich areas. Traditional propeller thrusters are prone to being entangled by fishing nets, seaweed, or rocks near coral reefs and sunken ship wrecks. In contrast, jet thrusters generate thrust by spraying seawater at high speed from nozzles through high-pressure water pumps, without the need for propeller rotation, fundamentally avoiding the risk of entanglement. At the same time, the nozzles of jet thrusters can rotate 360 degrees, quickly changing the direction of thrust, enabling the equipment to achieve flexible steering, lateral movement, and even backward movement — making them suitable for navigating in narrow spaces or complex terrains. In deep-sea archaeological tasks, underwater robots equipped with jet thrusters can go deep into the interior of sunken ships, move flexibly among the wrecks filled with porcelain and ironware, and accurately capture details of cultural relics without touching or damaging them; in ecological surveys of coral reef protected areas, they can travel freely through coral clusters, neither damaging the coral reef structure nor missing the opportunity for close-range observation of coral growth status, becoming a "powerful tool" for exploration in complex environments.

The three power types of thrusters are like the "three warriors" of deep-sea exploration, each occupying different scenarios with unique advantages. The "precision" of electric thrusters, "strength" of hydraulic thrusters, and "agility" of jet thrusters essentially represent the precise alignment between technology and needs. As deep-sea exploration extends to more diversified scenarios — from deep-sea scientific research to resource development, and from ecological protection to emergency rescue — the power selection of thrusters will become more refined. In the future, "hybrid power" propulsion systems may emerge, integrating the advantages of different power types to provide more comprehensive power support for more complex deep-sea tasks. However, this design logic of "scenarios determine power, and power serves scenarios" will always be the core logic driving the technological development of deep-sea thrusters.