Tugboat

A small, powerful vessel that maneuvers larger ships by pushing or towing them, especially in harbors and narrow waterways.

Bollard pull: The static pulling force a vessel can exert through a line while stationary. It measures the towing force available when a tug holds position against a ship or fixed point.
Harbor tug: A tug designed primarily to assist ships entering, leaving, or moving within a port. Harbor tugs provide the everyday push-and-pull assistance most associated with tugboats.
Displacement hull: A hull that moves through water by displacing a volume of water equal to its weight. Most tugs use displacement hulls suited to heavy work at modest speeds.
Pilot boat: A small, fast vessel that transports maritime pilots to and from ships. Pilot boats transfer people; tugboats apply force to control ships.
Steam tug: A tugboat powered by a steam engine driving a paddle wheel or propeller. Steam propulsion gave early tugs independent power to maneuver ships against wind and tide.
Azimuthing stern drive: A propulsion system whose steerable propellers rotate around vertical axes beneath a vessel. Rotating propellers give many harbor tugs strong thrust in nearly any direction.
Ship berthing: The maneuver of bringing a vessel alongside a quay, pier, or other berth. Tugs help large ships approach and hold position beside a berth.
Propeller: A rotating device that converts shaft power into thrust by accelerating water. A tug's propulsors generate the force needed to push or tow another vessel.
Mooring boat: A small workboat used to handle mooring lines and assist vessels at berths. Mooring boats manage lines, while tugs provide substantial pushing or towing force.
Sailing ship: A vessel propelled primarily by sails that harness wind power. Early tugs assisted sailing ships when wind or confined space hindered maneuvering.

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WinchRelated: Tugboats use winches to manage towlines and control towing operations.