Azimuth thruster

From Wikipedia, the free encyclopedia

Siemens Schottel azimuth thrusters
Siemens Schottel azimuth thrusters

An Azimuth thruster is a configuration of ship propellers placed in pods that can be rotated in any horizontal direction, making a rudder unnecessary. These give ships better maneuverability than a fixed propeller and rudder system. Primary advantages are electrical efficiency, better use of ship space, and lower maintenance costs. Ships with azimuth thrusters do not need tugs to dock, though they still require tugs to maneuver in difficult places.

There are two major variants, based on the location of the motor:

  1. Mechanical transmission, where a motor inside the ship is connected to the pod by gearing. The motor may be diesel or diesel-electric. Depending on the shaft arrangement the mechanical azimuth thruster are divided into L-drive and Z-drive. A L-drive thruster has a vertical input shaft and a horizontal output shaft with one right-angle gear. A Z-drive thruster has an horizontal input shaft, vertical shaft in the azimuthing column and a horizontal output shaft with two right-angle gears.
  2. Electrical transmission, where an electric motor is in the pod itself, connected directly to the propeller without gears. The electricity is produced by an onboard engine, usually diesel or gas turbine. Invented in 1955 by Mr. F.W. Pleuger and Mr. Friedrich Busmann (Pleuger Unterwasserpumpen GmbH), ABB Azipod was the first product using this technology.

Contents

[edit] Types of Mechanical Azimuth Thrusters

Mechanical azimuth thrusters are available as fixed installed, retractable and underwater-mountable. Mechanical azimuth thrusters are available with fixed pitch propellers FPP and controllable pitch propellers CPP.

  1. Fixed installed thrusters are used for tugs, ferries and supply-boats.
  2. Retractable thrusters are used as auxiliary propulsion for DP-vessels and take-home propulsion for military vessels.
  3. Underwater-mountable thrusters are used as DP-propulsion for very large vessels as semi-submersible drill rigs.

[edit] History

U.S. Patent 2,714,866  from 1955
U.S. Patent 2,714,866  from 1955

The first azimuth thrusters, using the mechanical Z-drive transmission, were built by Hollming in Finland in the 1960s under the Aquamaster brand name.[1] The business was later sold to Rolls-Royce, after the merger of Finnish shipyards into Finnyards.

Later, subsidiaries of ABB, also based in Finland, developed the Azipod thruster, with the motor located in the pod itself. This kind of propulsion was first patented in 1955 by Pleuger of Germany.

[edit] See also

[edit] References

  1. ^ Hollming Group - History

[edit] External links