TUGBOATS

TUGBOATS. Tugs range from the 50 foot harbor or yard tug to the 250 foot long off-shore anchor harboring tugs. They generally perform one of three tasks. The first is known as a "ship assist," as in helping larger ships in and out of harbors and ports. Tugboats also tow ships and barges which are not under their own power. Third, they aid in construction work taking place on or near a body of water. Although small for their size, tugboats have enormous power. Tugboat engines typically produce 500 to 2,500 kW (~ 680 to 3,400 hp).

Today's ships can move forward and backwards easily, but are usually unable to maneuver sideways. In a tug assist, one or two tugboats meet the larger ship while it is still outside the port. One tugboat behind the ship and attached to it by a line acts as a brake to slow down and stop the large ship. Another tugboat can be near the bow of the ship, at the port or starboard side, depending on which side the captain of the assisted ship wants to moor. This second tugboat is attached to the side of the ship by a line, allowing the tug to push or pull the boat in the desired direction.

Tugboats are also used for towing. They can move a floating object with no power of its own, such as a barge, or a "dead ship," a ship that is not under its own power and is moved from one location to another. A typical towing situation would involve one tugboat with a towing cable attached from the stern of the tug to the barge or dead ship. A tandem tow is when one tugboat is towing two barges in a line. Barges can be used to move almost anything that a ship can, and the tugboats move them from one place to another.

A tugboat in a construction project assists in construction by moving small barges carrying the construction equipment from place to place on a construction site. The tugboat can also act as a crew boat so that the construction crew can get around at crew change time.