MARINE PROPULSION OR STEERING

**Definition:** This place covers:

Propulsive elements directly acting on water, e.g.:

Effecting propulsion by jets, e.g. using reaction principle.

Propulsive devices directly acted on by wind, e.g.:

Effecting propulsion by use of vessel-mounted driving mechanisms co‑operating with anchored chains or the like.

Effecting propulsion by muscle power

Effecting propulsion of vessels, not otherwise provided for, e.g.

Outboard propulsion units and Z-drives.

Use of propulsion power plant or units on vessels:

Transmitting power from propulsion power plant to propulsive elements, e.g.

Steering and dynamic anchoring

Slowing down of vessels other than by propulsive elements

**Limiting references (this place does not cover):** - Propulsion of air-cushion vehicles -> B60V1/14 - Propulsion or steering specially adapted for submarines, other than nuclear propulsion -> B63G - Propulsion or steering specially adapted for torpedoes -> F42B19/00

**Glossary:** - Dynamic anchoring: Positioning of vessels or floating structures by means of propulsive elements. - Magnus effect: The phenomenon of a rotating object moving in a fluid generating a circulation and thus a lift perpendicular to the axis of rotation and to the direction of movement of the object. - Outboard drive: An outboard propulsion unit. - Outboard motor: An outboard propulsion unit comprising a motor mounted outboard integral with the power leg. - Outboard propulsion unit: A propulsion unit comprising a substantially vertical power leg mounted outboard of a hull and supporting a propulsive element. - Propeller slipstream: The current of water driven backward by a propeller. - Shrouding ring: A circular co-rotating band attached circumferentially, or at a given radius, to the rotor of a turbine, or to the blades of a propeller. - Tilt: Angular lifting movement of the outboard motor, or of the power leg from its operating position into an inoperative position with the propulsion element out of the water, and vice versa. - Trim: Angular position of the power leg relative to the boat's vertical axis when the power leg is in operating position. - Trolling plate: A plate movable in a position perpendicular to a vessel's longitudinal axis so as to slow down a moving vessel. - Universal joint: A joint between two shafts that allows for two angular degrees of freedom while being adapted for transmitting torque about the shafts' longitudinal axes between the two shafts, e.g. Cardan joint or Hooke's joint. - Z-drive: An in-board-outboard propulsion arrangement comprising an inboard motor, typically exhibiting a horizontal motor shaft, and a substantially vertical outboard power leg supporting a propulsive element, typically driven by a horizontal propeller shaft.