China has tested a deep-sea cutting system designed to operate at extreme ocean depths.

The device can slice through subsea structures, including cables and pipelines, under high pressure.

The trial signals progress in subsea engineering and industrial autonomy.

According to a SCMP report, the system was validated during a recent expedition in 2026.

Deep-sea cutting test

The research vessel Haiyang Dizhi 2 carried out the test at a depth of 3,500 meters.

The mission was led by China’s Ministry of Natural Resources.

Engineers deployed a compact electro-hydrostatic actuator, or EHA, to perform cutting operations.

The EHA combines a motor, hydraulic system, and control unit into a single device.

This design removes the need for external oil pipelines. Engineers say the approach improves reliability and reduces energy loss.

“The sea trial has bridged the ‘last mile’ from deep-sea equipment development to engineering application,” the official China Science Daily reported on Saturday, suggesting the equipment was poised for actual deployment.

The system also features pressure compensation and corrosion resistance. These upgrades allow it to function under intense subsea conditions.

The actuator can deliver high force while maintaining precise control.

Engineering leap underwater

Zhejiang University played a key role in developing the actuator. The project began as part of a 2023 initiative to advance deep-sea equipment.

Engineers designed the system to meet strict performance targets.

Documents show the actuator can withstand pressures above 35 megapascals.

It delivers over 50 kilonewtons of force. The system also achieves at least 1.0 kilowatt of drive power.

“The system packs the pump, valve, cylinder and controls into a single unit. It removes the need for external hydraulic lines, making the equipment more reliable, more energy efficient and cleaner.”

“The technology is under trial for cutting subsea cables and operating deep-sea grabs, opening a new path for powering underwater work,” the report added.

The same technology already appears in commercial aviation systems.

Aircraft use similar actuators to control flight surfaces. Engineers adapted the concept for deep-sea use by reinforcing materials and sealing components.

The new system expands China’s subsea capabilities beyond earlier tools.

Previous domestic cutting systems operated at depths of up to 2,000 meters. This new device extends that limit to 3,500 meters.

According to SCMP, the upgrade could support offshore energy operations.

It may also assist in clearing underwater obstacles and repairing infrastructure. Faster cutting times could improve efficiency in pipeline recovery missions.

The expedition included more than 100 personnel from multiple institutions.

Teams conducted over 10 research tasks during the 30-day mission.

The vessel also tested deep-sea sampling systems and recovery tools.

A remotely operated vehicle named “Haima” retrieved seabed instruments during the mission.

Crews also tested equipment designed for operations at depths of up to 10,000 meters.

The development highlights growing investment in subsea engineering systems.

It also reflects a push to reduce reliance on foreign industrial tools.