Tugboat

Seagoing tugs (deep-sea tugs or ocean tugboats) fall into four basic categories: Compared with seagoing tugboats, harbour tugboats that are employed exclusively as ship assist vessels are generally smaller and their width-to-length ratio is often higher, due to the need for the tugs' wheelhouse to avoid contact with the hull of a ship, which may have a pronounced rake at the bow and stern.

[2] Also, in many ports, tankers are required to have tug escorts when transiting in harbors to render assistance in the event of mechanical failure.

The port generally mandates a minimum horsepower or bollard pull, determined by the size of the escorted vessel.

Their hulls feature a flat front or bow to line up with the rectangular stern of the barge, often with large pushing knees.

Tugboats usually have an extreme power:tonnage-ratio; normal cargo and passenger ships have a P:T-ratio (in kW:GRT) of 0.35 to 1.20, whereas large tugs typically are 2.20 to 4.50 and small harbour-tugs 4.0 to 9.5.

The cycloidal propeller (see below) was developed prior to World War II and was occasionally used in tugs because of its maneuverability.

After World War II it was also linked to safety due to the development of the Voith Water Tractor, a tugboat configuration that could not be pulled over by its tow.

Although sometimes referred to as the Aquamaster or Schottel system, many brands exist: Steerprop, Wärtsilä, Berg Propulsion, etc.

The thrust-to-power ratio is enhanced because the water approaches the propeller in a linear configuration and exits the nozzle the same way.

[8] It adds a pair of interlocking rings to the body of the tug, the inner on the boat, the outer on the ship by winch or towing hook.

On a weekend in May, eight tugboats perform choreographed movements for about an hour to the tunes of waltz and other sorts of dance music.

Tugger follows Crowe as he engages various people in physical conflicts, providing emotional support and comic relief.

At one point Tugger even attempts to commit suicide, upon being forced to hear Russell Crowe's new musical composition.

Tugboat CSS Teaser is captured by USS Maratanza .
Justine McAllister , a tug boat in New York Harbor , January 2008
The tugboats Reid McAllister and McAllister Responder push the LPG tanker BW Volans into port at Marcus Hook on the Delaware River.
Fleet tug USS Tawasa (1,255 tons, 205 ft), which towed a nuclear depth charge as it was detonated in Operation Wigwam in 1955
Articulated tug and barge (ATB)
Svitzer Tyr , a Danish tugboat, built in China in 2011, pictured in 2018 in Ystad harbour
River tug pushing a log raft in British Columbia near Vancouver (May 2012)
A tugboat on the Arakawa River in Tokyo , Japan
Diagram of components
Red Cloud (foreground), a type V2-ME-A1 tug, alongside USNS David C. Shanks , outside the Oakland Bay Bridge in San Francisco Bay, California, 1950s. On the bow is a traditional rope tugboat fender .
South African Naval tugs perform a "ballet" when welcoming a new member of the fleet.
Theodore Tugboat , the titular hero of a children's show, was popular enough that a fullsize replica was constructed.