The Voith-Schneider propeller is a specialized marine propulsion system. It is highly maneuverable, being able to change the direction of its thrust, almost instantaneously. This article needs to be cleaned up to conform to a higher standard of quality. ... The worlds oceans as seen from the South Pacific Ocean (from Okeanos, Greek for river, the ancient Greeks noticed that a strong current flowed off Gibraltar, and assumed it was a great river); covers almost three quarters (71%) of the surface of the Earth, and nearly half of the... Propulsion method may refer to a number of different articles: For a list of space transport methods, see spacecraft propulsion. ... Thrust is a reaction force described quantitatively by Newtons Second and Third Law. ...

From a circular plate, rotating around a vertical axis, a circular array of vertical blades (in the shape of airfoils) are protruding out of the bottom of the ship, each blade can rotate a bit itself around a vertical axis. The internal gear changes the angle of attack of the blades, in synch with the rotation of the plate, so that each blade can provide thrust in any direction, very similar to the collective pitch control and cyclic in a helicopter. An airfoil (in American English, or aerofoil in British English) is the shape of a wing or blade (of a propeller or ships screw) as seen in cross-section. ... In this diagram, the black arrow represents the direction of the wind. ... The Bell 206 of Canadian Helicopters Robinson Helicopter Company (USA) R44, a four seat development of the R22 A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors (propellers). ...

Unlike a Z-drive (where a conventional propeller is tilted on a vertical rudder axis) changing the direction of thrust merely requires changing the pattern by which the vertical blades change their orientation. In a marine situation this provides for a drive which can be directed in any direction and thus does away with the need for a rudder. It is highly efficient and provides for an almost instantaneous change of direction. These drives are becoming increasingly common in work boats such as fireboats and tugboats where extreme manoeuvreability is a very useful characteristic. The Z-drive is a specialized form of marine propulsion. ... See Tug (disambiguation) for alternative meanings of tug. ...

There are advantages and disadvantages in using marine cycloidal drives relative to say, a Kort nozzle or Z-drive. The cycloidal drive will be more efficient and faster to manoeuvre but the other systems are likely to be significantly cheaper in both the long and short term. A choice is made on the basis of perceived performance requirements. Also the blades of the drive protrude from the bottom of the hull making shallow water operation a problem. Kort nozzle section The Kort nozzle is a shrouded, ducted propeller assembly for marine propulsion. ... A hull is: the outer covering of a fruit or vegetable, may also be called a husk the body or frame of a ship; see hull (ship) Several places in the world are called Hull: Kingston upon Hull - a city in England usually referred to as simply Hull. ...

External links

• The Voith-Schneider home-page
• Explanation, diagrams and animation showing a Voith-Schneider rotor in action