The Voith Schneider Propeller (VSP) is a specialized

marine propulsion Marine propulsion is the mechanism or system used to generate thrust to move a watercraft through water. While paddles and sails are still used on some smaller boats, most modern ships are propelled by mechanical systems consisting of an electr ...

system (MPS) manufactured by the Voith Group based on a

cyclorotor A cyclorotor, cycloidal rotor, cycloidal propeller or cyclogiro, is a fluid propulsion device that converts shaft power into the acceleration of a fluid using a rotating axis perpendicular to the direction of fluid motion. It uses several blades wi ...

design. It is highly maneuverable, being able to change the direction of its

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that sys ...

almost instantaneously. It is widely used on tugs and

ferries A ferry is a ship, watercraft or amphibious vehicle used to carry passengers, and sometimes vehicles and cargo, across a body of water. A passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water tax ...

Operation

From a circular plate, rotating around a vertical axis, a circular array of vertical blades (in the shape of hydrofoils) protrude out of the bottom of the ship. Each blade can rotate itself around a vertical axis. The internal gear changes the angle of attack of the blades in sync with the rotation of the plate, so that each blade can provide thrust in any direction. Unlike the

azimuth thruster An azimuth thruster is a configuration of marine propellers placed in pods that can be rotated to any horizontal angle (azimuth), making a rudder unnecessary. These give ships better maneuverability than a fixed propeller and rudder system. Ty ...

(where a conventional propeller is rotated about the vertical axis to direct its thrust, allowing a vessel to steer without the use of a rudder), the Voith-Schneider drive merely requires changing the pattern of orientation of the vertical blades. 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 A rudder is a primary control surface used to steer a ship, boat, submarine, hovercraft, aircraft, or other vehicle that moves through a fluid medium (generally air or water). On an aircraft the rudder is used primarily to counter adve ...

. It is highly efficient and provides for an almost instantaneous change of direction. These drives are becoming increasingly common in work boats such as

fireboat A fireboat or fire-float is a specialized watercraft with pumps and nozzles designed for fighting shoreline and shipboard fires. The first fireboats, dating to the late 18th century, were tugboats, retrofitted with firefighting equipme ...

s and

tugboat A tugboat or tug is a marine vessel that manoeuvres other vessels by pushing or pulling them, with direct contact or a tow line. These boats typically tug ships in circumstances where they cannot or should not move under their own power, su ...

s where extreme manoeuvrability is needed. Azimuth thrusters (and

Kort nozzle A ducted propeller, also known as a Kort nozzle, is a marine propeller fitted with a non-rotating nozzle. It is used to improve the efficiency of the propeller and is especially used on heavily loaded propellers or propellers with limited di ...

s) have both advantages and disadvantages when compared to cycloidal drives. The azimuth thruster is less efficient and slower to manoeuvre, but is likely to be cheaper in the short term. Life cycle costs favour the Voith solution, something reflected in the residual value of a Voith water tractor. A choice is made on the basis of perceived performance requirements. Instead of a Kort nozzle, VSPs are often fitted with a "thrust plate" or "propeller guard" which acts as a nozzle at low speed, protects the VSP against grounding and provides another blocking location during drydocking. A low

acoustic signature The term acoustic signature is used to describe a combination of acoustic emissions of sound emitters, such as those of ships and submarines. In addition, aircraft, machinery, and living animals can be described as having their own characteristic ...

favours the device's use in

minesweepers A minesweeper is a small warship designed to remove or detonate naval mines. Using various mechanisms intended to counter the threat posed by naval mines, minesweepers keep waterways clear for safe shipping. History The earliest known usage of ...

by minimising cavitation (usually produced at the tips of axial propellers) as the rotor does not need to rotate as fast for a given thrust. The underwater sound signature of the MV ''North Sea Giant'' (IMO: 9524073, MMSI: 248039000) dynamic positioning vessel was measured by the International Centre for Island technology (ICIT) whilst installing a foundation monopile for the Voith tidal energy device in the Fall of Warness, Orkney (Ref Beharie and Side, 2011). VSPs are offered with an input power range of 160 kW to 3900 kW File:VSPforces.jpg, Lift forces imparted to the VSP from the water body File:VSPcycloide.jpg, Path of a blade in the water

History

The Voith Schneider propeller was originally a design for a

hydro-electric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

turbine A turbine ( or ) (from the Greek , ''tyrbē'', or Latin ''turbo'', meaning vortex) is a rotary mechanical device that extracts energy from a fluid flow and converts it into useful work. The work produced by a turbine can be used for generating ...

. Its Austrian inventor, Ernst Schneider, had a chance meeting on a train with an employee of Voith's subsidiary St. Pölten works; this led to the turbine being investigated by Voith's engineers, who discovered that although it was no more efficient than other water turbines, Schneider's design worked well as a pump by reversing the flow through the device. By changing the orientation of the vertical blades, it could be made to function as a combined propeller and

. In 1928 a prototype was installed in a 60-hp motor launch named ''Torqueo'' (Latin:''I spin'') and trials were carried out on Lake Constance. A number of German minesweepers (

R boats The R boats (''Räumboote'' in German, meaning ''minesweeper'') were a group of small naval vessels built as Minesweeper (ship), minesweepers for the ''Kriegsmarine'' (German navy) before and during the Second World War. They were used for severa ...

) were fitted with VSPs; the first of these was the R8, built in 1929 by

Lürssen Lürssen (or Lürssen Werft) is a German shipyard with headquarters in Bremen-Vegesack and shipbuilding facilities in Lemwerder, Berne and Bremen-Fähr-Lobbendorf. Lürssen designs and constructs yachts, naval ships and special vessels. Tradi ...

. By 1931 VSPs were being fitted in new vessels on Lake Constance run by the German State Railways. The first such ship to use the Voith Schneider propeller was the excursion boat ''Kempten''. Two German 1935-type M class minesweepers ''M-1'' and ''M-2'' were fitted with VSPs. The first British ship to use Voith Schneider propellers was the double-ended Isle of Wight ferry '' MV Lymington'', launched in 1938. Some 80 ships had been installed with VSPs by the end of the 1930s, including the uncompleted 1938 German aircraft carrier '' Graf Zeppelin'' (two auxiliary units in the bow), and the Japanese submarine cable laying ship ''Toyo-maru'' (also 1938). The three vessels (''John Burns'', ''Ernest Bevin'', and ''James Newman'') currently used by the

Woolwich Ferry The Woolwich Ferry is a free vehicle and pedestrian ferry across the River Thames in East London, connecting Woolwich on the south bank with North Woolwich on the north. It is licensed and financed by London River Services, the maritime arm of ...

feature Voith-Schneider propulsion systems. They were built in 1963 by the

Caledon Shipbuilding & Engineering Company The Caledon Shipbuilding & Engineering Company, Limited was a major Scottish shipbuilding company based in Dundee, Scotland that traded for more than a century and built more than 500 ships. History W.B. Thompson CBE (1837 - 1923) founded th ...

of Dundee and feature one VSP in the bow and a second in the stern for remarkable maneuverability. The Tay Ferries ''Scotscraig'' and ''Abercraig'' which were built by the Caledon in the 1950s also used VSPs. The US Navy built twelve VSP-equipped ''Osprey''-class coastal minehunters in the 1990s. These vessels have been decommissioned, six were sold to foreign navies. and six were sold for "dismantlement purposes only." The

French Navy The French Navy (french: Marine nationale, lit=National Navy), informally , is the maritime arm of the French Armed Forces and one of the five military service branches of France. It is among the largest and most powerful naval forces in t ...

operates sixteen tugboats of the RPC12 type, that can provide a 12-tonne

bollard pull Bollard pull is a conventional measure of the pulling (or towing) power of a watercraft. It is defined as the force (in tonnes force, or kilonewtons (kN)) exerted by a vessel under full power, on a shore-mounted bollard through a tow-line, commonl ...

thanks to two Voith Schneider propellers.Remorqueur type RPC 12 : Caractéristiques principales
''NetMarine'' The same device, mounted on a horizontal rather than a vertical axis, has been used to provide lift and propulsion on a few experimental aeroplanes, known as " cyclogyros". None of them were very successful. It has also more recently been proposed as an alternative to rotors for drone applications.

References

* *

External links

Voith Turbo marine website"Sea Going Eggbeaters"
''Popular Mechanics'', March 1950, pp. 102 - 103.
"Download of PC application iVSP"
* {{Cite web , title=The Voith Schneider Propeller Current Applications and New Developments , first=Dirk , last=Jürgens , year=2006 , publisher=Voith , url=https://pdfs.semanticscholar.org/b2d7/8bedbdff5893120de12a7a1d128045e8712d.pdf Propellers Tugboats Marine propulsion

Operation

History

See also

References

External links