Wiki article on this topic: A tugboat is a type of vessel that maneuvers other vessels by pushing or pulling them either by direct contact or by means of a tow line. Tugs typically move vessels that either are restricted in their ability to maneuver on their own, such as ships in a crowded harbor or a narrow canal, or those that cannot move by themselves, such as barges, disabled ships, log rafts, or oil platforms. Tugboats are powerful for their size and strongly built, and some are ocean-going. Some tugboats serve as icebreakers or salvage boats. Early tugboats had steam engines, but today most have diesel engines. Many tugboats have firefighting monitors, allowing them to assist in firefighting, especially in harbors.
Seagoing tugs fall into four basic categories:
Compared to seagoing tugboats, harbour tugboats are generally smaller and their width-to-length ratio is often higher, due to the need for a lower draught. In smaller harbours these are often also termed lunch bucket boats, because they are only manned when needed and only at a minimum , thus the crew will bring their own lunch with them. The number of tugboats in a harbour varies with the harbour infrastructure and the types of tugboats. Things to take into consideration include ships with/without bow thrusters and forces like wind, current and waves and types of ship.
River tugs are also referred to as towboats or pushboats. Their hull designs would make open ocean operation dangerous. River tugs usually do not have any significant hawser or winch. Their hulls feature a flat front or bow to line up with the rectangular stern of the barge, often with large pushing knees.
Tugboat engines typically produce 500 to 2,500 kW , but larger boats can have power ratings up to 20,000 kW. Tugboats usually have an extreme power:tonnage-ratio; normal cargo and passenger ships have a P:T-ratio 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 engines are often the same as those used in railroad locomotives, but typically drive the propeller mechanically instead of converting the engine output to power electric motors, as is common for diesel-electric locomotives. For safety, tugboats' engines often feature two of each critical part for redundancy.
Tugboat is a free transparent clipart image selected by Jerk cliparts.
The resolution of the first clip art image is 1855 x 1389 px
and classified to .
Try search service at Jerk cliparts and you can quickly find more transparent background
images related to Tugboat.