Voith Schneider "Propeller" (VSP), also "cycloidal Drive"

Aidan Lee posted, cropped
Blades instead of props. The Ocean A. Gauthier tractor tug showing her 6’ long voith blades that provide responsive thrust in any direction with her Voith Schneider unconventional propulsion.
Lorry Smith: Seattle at one time had tug boat races . The Foss tug with this system would win going sideways.
Douglas Semack: https://youtu.be/Pao8fj3jsls?si=BhV4PbEH-_ebFBp9
The VSP powered Tugs are extremely powerful.

The Scow posted two photos with the comment:

Two drawings from the book I am working on. These whow a Voith Schneider tugboat propulsion unit and a diagram of how it works. The blades extend down into the water beneath the boat. 

The blades go in a circle like a merry go round, and when they are in neutral each blade stays in line with the circle for its entire revolution. To generate thrust, the linkage in the center shifts, which makes each blade twist when it reaches the points on the circle where it will push the water in the desired direction.

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Jacobs Ben commented on the above post
Voith tractor captain since 2006 🤟🏻 Next week I’m going to Damen for an RSD tug course. I can write my name with voith, but can’t even moore a tug with RSD 🤣

Pascal Riteau commented on the above post
"Real life", double VS tractor tug COGNAC

Michael Gates commented on the above post

7:07 video @ 1:51
It can go from full forward to full reverse in 5 seconds.

Note the propwash coming from underneath the pilothouse on the lead tugboat. I presume that it has a Voith Schneider "Propeller" (VSP) rather than a standard screw propeller. Or maybe it is a bow mounted Z-drive.

1:32:55 video @ 1:18:04 via Dennis DeBruler

Caution: I've seen some The Marine Buff posts with some serious errors so I don't know if all of this is correct.

The Marine Buff posted

The Voith Schneider Propeller (VSP) is a highly maneuverable marine propulsion system developed by Austrian engineer Ernst Schneider. It combines propulsion and steering in one unit by using vertical blades that rotate around a central axis, allowing for precise and instant changes in thrust direction. This design eliminates the need for a rudder and is particularly effective in applications requiring extreme maneuverability, such as tugs, fireboats, and ferries.

It's unique mechanism involves a circular disk with controllable blades mounted at a 90-degree angle. The magnitude of thrust is determined by the disk's rotational speed, while the blade angle dictates the thrust direction. This system is highly efficient and allows vessels to maintain precise positions even under adverse conditions.

One notable advantage of the Voith Schneider Propeller is its low acoustic signature, making it suitable for use in minesweepers where minimizing underwater noise is crucial. Additionally, the VSP's ability to provide powerful thrust in all directions ensures reliable operation even if one engine fails. However, the downward-protruding blades can pose a risk in shallow waters.

Modern adaptations, such as the electric Voith Schneider Propeller (eVSP), integrate the benefits of the traditional VSP with electric motors, enhancing energy efficiency and environmental sustainability. The eVSP is optimized for offshore and ferry applications and provides maximum thrust with precise control.

Rickie Lee Woytowich: Most of the current fleet of Staten Island Ferries use them. At roughly 18 knots, they're probably toward the high end of the speed range for these units.

Alexandre Gravel commented on the above post