Navy’s new crane moves load from ship-to-ship despite rolling seas

Sept. 8, 2011
Navy’s new crane moves load from ship-to-ship despite rolling seas

Crews on naval ships will have an easier time loading and receiving cargo from other ships while at sea, thanks to development of the Large Vessel Interface Lift On/Lift Off Crane at the Office of Naval Research. The motion-compensating crane delivers fully loaded cargo containers between ships at sea using computer control over its six degrees of freedom, and it can do so despite winds up to 20 knots and waves up to 7.5 ft (Sea State 4).

The crane is outfitted with a suite of sensors that detect the position and motion of the crane, the ship it’s mounted on, and the payload. An eccentric arm attaches to the ship and a boom then extends out to support an eight-wire inverted Stewart platform. A pair of wires attaches to each of the upper corners of a standard 20-ft ISO container. Relative motion between the ships, as well as the container, are damped out by computer-controlled motion of the eccentric arm and boom and the inherent stabilizing tendencies of the inverted Stewart platform.

In tests, the crane successfully picked up and moved containers between ships in the Gulf of Mexico, and even lowered them into holes, despite obstructed views on the part of the crane operator and waves up to 3-ft high. If deployed on ships, the crane could move cargo containers between ships at sea, a task now only possible when ships are in deep-water ports. It would also reduce the number of sailors needed to operate a shipborne crane from 10 to three.

© 2011 Penton Media, Inc.

Sponsored Recommendations

Pumps Push the Boundaries of Low Temperature Technology

June 14, 2024
As an integral part of cryotechnology, KNF pumps facilitate scientific advances in cryostats, allowing them to push temperature boundaries and approach absolute zero.

The entire spectrum of drive technology

June 5, 2024
Read exciting stories about all aspects of maxon drive technology in our magazine.


May 15, 2024
Production equipment is expensive and needs to be protected against input abnormalities such as voltage, current, frequency, and phase to stay online and in operation for the ...

Solenoid Valve Mechanics: Understanding Force Balance Equations

May 13, 2024
When evaluating a solenoid valve for a particular application, it is important to ensure that the valve can both remain in state and transition between its de-energized and fully...

Voice your opinion!

To join the conversation, and become an exclusive member of Machine Design, create an account today!