As a key part of China’s comprehensive transportation system, inland waterway shipping is accelerating its transition toward green and intelligent development. Driven by the goals of "carbon peaking and carbon neutrality", new energy vessels such as battery-electric ships and hydrogen fuel cell ships have become mainstream in inland navigation. As the "heart" of a vessel, the propulsion system directly determines the energy efficiency, maneuverability and economic performance of new energy ships. With its high efficiency, flexibility and integrated design, the 100kW full-revolving azimuth thruster has become an ideal power solution for small and medium-sized new energy vessels in inland waterways, providing critical technical support for the green upgrading of inland shipping.

I. 100kW Full-Revolving Azimuth Thruster: Technical Principle and Core Advantages

(I) Technical Principle

The full-revolving azimuth thruster is an electric propulsion unit that integrates the propulsion motor and propeller into an underwater pod, which can rotate 360° through a slewing mechanism. The 100kW model adopts permanent magnet synchronous motor direct-drive technology, eliminating the traditional gearbox. The motor output shaft is directly connected to the propeller; electric power is transmitted to the underwater pod via cables to drive the propeller and generate thrust. The slewing mechanism, driven by a servo motor or hydraulic system, allows precise adjustment of the pod angle, enabling omnidirectional thrust control. Steering, sideways movement and on-the-spot rotation can be achieved without a conventional rudder.

(II) Core Advantages

High Efficiency and Energy Saving, Matching New Energy Power

The direct-drive structure completely eliminates 8%–12% mechanical loss from gearboxes, improving overall system efficiency by 10%–15% compared with traditional shaft propulsion. The 100kW thruster delivers high torque at low speeds, perfectly matching the dynamic characteristics of new energy vessels, especially battery-electric ships. It significantly reduces battery consumption and extends cruising range, meeting the core demands of zero emissions and low energy consumption for inland new energy vessels.

Superior Maneuverability for Complex Inland Waterways

With 360° omnidirectional vector thrust, the vessel can perform 360° on-the-spot turning, lateral shifting and precise low-speed positioning. It easily adapts to narrow channels, curved water areas and berthing conditions without frequent course adjustments. Response speed is more than 50% higher than traditional propulsion-and-rudder systems, greatly reducing risks of collision and grounding. It is especially suitable for inland tourist ships, working boats and small cargo ships requiring high maneuverability.

Integrated Design for Space and Cost Savings

The azimuth thruster integrates propulsion and steering, eliminating long shafting, rudders, gearboxes and other complex components, increasing engine room space utilization by 20%–27%. The compact, lightweight 100kW unit is easy to install and maintain, reducing shipbuilding costs. With reliable underwater sealing, routine maintenance is limited to pod sealing and propeller inspection, cutting operation and maintenance costs by more than 30% compared with conventional systems.

Low Noise and Vibration for Improved Navigation Experience

The elimination of gearbox transmission and the underwater motor layout reduce mechanical noise and vibration at the source. Cabin noise can be reduced by 10–15 dB with significantly lower vibration levels. This advantage is particularly valuable for inland tourist vessels and official ships, enhancing comfort for passengers and crew while complying with green inland shipping standards.

II. Current Development of Inland New Energy Vessels and Pain Points of Traditional Propulsion Systems

(I) Development Trend of Inland New Energy Vessels

China’s inland new energy vessels have entered large-scale application. By the end of 2024, there were 485 battery-powered inland ships, mainly tourist vessels and short-distance ferries; more than 600 LNG-fueled ships were in operation, and hydrogen fuel cell and methanol-powered ships had achieved pilot applications. Supported by policies from the Ministry of Transport, many regions have launched "oil-to-electric" and battery-swapping pilots. The market for inland new energy vessels is expanding rapidly, with an expected market size of 36.75 billion yuan for electric ships by 2026.

(II) Pain Points of Traditional Propulsion Systems

Most small and medium-sized inland new energy vessels (30–50m tourist ships, working boats, small cargo ships) use traditional shaft propulsion with rudders, which present obvious drawbacks: high mechanical loss leading to low battery energy utilization and insufficient endurance; poor maneuverability causing difficulties in narrow waterways and low berthing efficiency; large space occupation by shafting and rudders reducing battery and cargo space; high noise and vibration harming comfort; and complex, costly maintenance. These issues have become major obstacles to the promotion of small and medium-sized inland new energy vessels.

III. Typical Applications of 100kW Full-Revolving Azimuth Thruster on Inland New Energy Vessels

(I) Inland Battery-Electric Tourist Ships

Inland tourist ships (e.g., sightseeing boats on Yangtze River tributaries and canals) have high requirements for comfort, maneuverability and environmental performance. The 100kW azimuth thruster ensures quiet and stable sailing, and its 360° rotation facilitates flexible berthing and viewing in scenic areas. Its high-efficiency direct drive greatly improves battery endurance to support 6–8 hours of sightseeing. For example, a pure electric sightseeing boat in Shennongxi, Hubei, uses a 240kW azimuth thruster to achieve zero emissions and low noise, setting a benchmark for green upgrading of inland tourist ships.

(II) Inland Official/Working Vessels

Maritime patrol boats, channel maintenance ships and port working boats require frequent starting, stopping, turning and positioning, demanding high mobility. The 100kW azimuth thruster enables precise low-speed control, with on-the-spot turning and sideways movement greatly improving operational efficiency in complex environments such as the main Yangtze River and inland ports. When applied to "oil-to-electric" official ships of the Changjiang Maritime Safety Administration, it can improve speed and maneuverability while reducing maintenance costs without changing battery capacity.

(III) Small Inland New Energy Cargo Ships/Barges

Short-distance small inland cargo ships and container barges (500–2000 tons deadweight) require high energy efficiency and reliability from propulsion systems. The 100kW azimuth thruster is compatible with battery-electric and methanol-battery hybrid power systems. Its high-efficiency direct drive lowers energy consumption, and its integrated design saves engine room space for batteries or cargo. In inland ports such as Wuhan and Yichang, small electric barges equipped with 100kW azimuth thrusters adopt a "vessel-battery separation" swapping mode, completing battery replacement in 30 minutes for a range of 100–150 km on inland routes.

(IV) Inland Intelligent/Unmanned Test Vessels

Intelligent and unmanned inland ships represent the future direction, requiring highly precise and responsive propulsion systems. The 100kW azimuth thruster can be deeply integrated with the ship’s intelligent control system to achieve precise vector thrust adjustment, supporting BEV multi-task perception networks for autonomous collision avoidance and automatic berthing. The "Jingzhe" inland autonomous navigation test vessel in Zhejiang uses full-revolving propulsion technology, improving maneuverability by 50% and supporting the development of intelligent inland shipping.

IV. Application Benefits and Future Prospects

(I) Comprehensive Benefits

Environmental Benefits:

Combined with new energy power, it achieves zero emissions for inland vessels. Each ship can reduce fuel consumption by 50–100 tons per year and carbon emissions by 130–260 tons per year, supporting carbon peaking and neutrality in inland shipping.

Economic Benefits:

System efficiency improved by 10%–15% reduces energy costs by 15%–20%; integrated design lowers construction costs, O&M costs by over 30%, with an investment payback period shortened to 3–5 years.

Social Benefits:

Improves safety and comfort of inland navigation, promotes green upgrading of inland tourism and freight industries, and supports the development of "green waterways and beautiful inland rivers".

(II) Future Prospects

With the large-scale development of inland new energy vessels, the 100kW full-revolving azimuth thruster will enjoy broader application. Domestically designed and manufactured 100kW azimuth thrusters have broken international monopolies and continue to reduce costs. Applications will expand to small inland engineering ships and fishing vessels, with deeper integration with battery-swapping and hydrogen fuel cell technologies. In the future, with the advancement of intelligent shipping, the 100kW full-revolving azimuth thruster will become standard equipment for inland new energy vessels, driving a comprehensive transition of inland shipping toward "green, efficient and intelligent" operations.

Conclusion

With its core advantages of high efficiency, flexibility and integration, the 100kW full-revolving azimuth thruster precisely meets the development needs of inland new energy vessels and solves many pain points of traditional propulsion systems. Amid the green transformation of inland shipping, this thruster will become the preferred power solution for small and medium-sized new energy vessels, injecting strong momentum into the high-quality development of China’s inland shipping and helping build a world-class green inland shipping system.