A Z-drive is a type of

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 ...

unit. Specifically, it is an

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 ...

. The pod can rotate 360 degrees allowing for rapid changes in thrust direction and thus vessel direction. This eliminates the need for a conventional

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 aircraft, air or watercraft, water). On an aircraft the rudder is used primarily to ...

. The Z-drive is so named because of the appearance (in

cross section Cross section may refer to: * Cross section (geometry) ** Cross-sectional views in architecture & engineering 3D *Cross section (geology) * Cross section (electronics) * Radar cross section, measure of detectability * Cross section (physics) **Abs ...

) of the mechanical

driveshaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connec ...

or transmission configuration used to connect the mechanically supplied driving energy to the ''Z-Drive'' azimuth thruster device. This form of power transmission is called a Z-drive because the rotary motion has to make two right angle turns, thus resembling the letter "Z". This name is used to differentiate the arrangement of drive to that of the

L-drive An L-drive is a type of azimuth thruster where the electric motor is mounted vertically, removing the second bevel gear from the drivetrain. Azimuth thruster pods can be rotated through a full 360 degrees, allowing for rapid changes in thrust direc ...

. It does not refer to an electric motor in a rotating pod. The device is different from the

Voith-Schneider 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 ...

marine propulsion system (also mechanically linked), which can also quickly change the direction of thrust, as the ''Z-drive'' uses a shrouded conventional

screw A screw and a bolt (see '' Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helical ridge, called a ''male thread'' (external thread). Screws and bolts are used to fa ...

that pivots or rotates the propeller, unlike the variable-geometry blades of the Voith-Schneider. Z-drive on Ile de Bréhat

Origins

The Z-drive transmission was invented in 1950 by Joseph Becker, the founder of Schottel, and used in the first azimuth thrusters built by Schottel GmbH in Germany in the 1960s under the ''Schottel'' brand name and referred to as RudderPropeller ever since. Joseph Becker was awarded the Elmer A. Sperry Award for this invention as a major contribution to the improvement of transportation worldwide.

Types

*Counter-rotating *Integrally installed/hull installation *Deck mounted outboard *Retractable

Origins

Types

Applications

See also

References

External links