A TUG (TUGBOAT) is a boat or ship that maneuvers vessels by pushing or towing them. Tugs move vessels that either should not move by themselves, 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.
* 1 Types of tugboats
* 1.1 Deep-sea tugs
* 3 Tugboats in popular culture
* 3.1 Film and television * 3.2 Literature
TYPES OF TUGBOATS
Swedish harbour tug Svitzer Freja in tug-operation (3,600 kW /
453 gross register tons (GRT) ) Dutch river tugboat "Mascotte
II" German harbour-tug and DDR quick-freighter Karl Marx at
Seagoing tugs (deep-sea tugs or ocean tugboats) fall into four basic categories:
* The standard seagoing tug with model bow that tows its "payload" on a hawser . * The "notch tug" which can be secured in a notch at the stern of a specially designed barge, effectively making the combination a ship. This configuration is dangerous to use with a barge which is "in ballast" (no cargo) or in a head- or following sea. Therefore, "notch tugs" are usually built with a towing winch. With this configuration, the barge being pushed might approach the size of a small ship, with interaction of the water flow allowing a higher speed with a minimal increase in power required or fuel consumption. * The "integral unit", or "integrated tug and barge" (ITB), comprises specially designed vessels that lock together in such a rigid and strong method as to be certified as such by authorities (classification societies) such as the American Bureau of Shipping , Lloyd\'s Register of Shipping , Indian Register of Shipping , Det Norske Veritas or several others. These units stay combined under virtually any sea conditions and the tugs usually have poor sea-keeping designs for navigation without their barges attached. Vessels in this category are legally considered to be ships rather than tugboats and barges must be staffed accordingly. These vessels must show navigation lights compliant with those required of ships rather than those required of tugboats and vessels under tow. * "Articulated tug and barge" (ATB) units also utilize mechanical means to connect to their barges. The tug slips into a notch in the stern and is attached by a hinged connection. ATBs generally utilize Intercon and Bludworth connecting systems. ATBs are generally staffed as a large tugboat, with between seven and nine crew members. The typical American ATB operating on the east coast customarily displays navigational lights of a towing vessel pushing ahead, as described in the 1972 ColRegs .
San Francisco harbor tractor tug "Delta Deanna"
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 (captain and deckhand), 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 includes ships with/without bow thrusters and forces like wind, current and waves and types of ship (e.g. in some countries there is a requirement for certain numbers and sizes of tugboats for port operations with gas tankers ).
Tug boat pushing a log raft near
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.
A tugboat is typically rated by its engine's power output and its overall bollard pull . The largest commercial harbour tugboats in the 2000s-2010s, used for towing container ships or similar, had around 60 to 65 short tons-force (530–580 kN) of bollard pull, which is described as 15 short tons-force (130 kN) above "normal" tugboats. Diagram of components
Tugboats are highly maneuverable, and various propulsion systems have
been developed to increase maneuverability and increase safety. The
earliest tugs were fitted with paddle wheels , but these were soon
replaced by propeller-driven tugs. Kort nozzles have been added to
increase thrust per kW/hp. This was followed by the nozzle-rudder,
which omitted the need for a conventional rudder . The cycloidal
propeller was developed prior to
World War II
The Kort nozzle is a sturdy cylindrical structure around a special propeller having minimum clearance between the propeller blades and the inner wall of the Kort nozzle. The thrust-to-power ratio is enhanced because the water approaches the propeller in a linear configuration and exits the nozzle the same way. The Kort nozzle is named after its inventor, but many brands exist.
A recent Dutch innovation is the Carousel Tug , winner of the Maritime Innovation Award at the Dutch Maritime Innovation Awards Gala in 2006. The Carousel Tug adds a pair of interlocking rings to the body of the tug, the inner ring attached to the boat, with the outer ring attached to the towed ship by winch or towing hook. Since the towing point rotates freely, the tug is very difficult to capsize.
From a circular plate, rotating around a vertical axis, a circular array of vertical blades (in the shape of hydrofoils ) protrude out of the bottom of the ship. Each blade can rotate itself around a vertical axis. The internal gear changes the angle of attack of the blades in sync with the rotation of the plate, so that each blade can provide thrust in any direction, very similar to the collective pitch control and cyclic in a helicopter.
TUGBOATS IN POPULAR CULTURE
Tugboat Annie was the subject of a series of Saturday Evening Post
magazine stories featuring the female captain of the tugboat Narcissus
FILM AND TELEVISION
To date, there have been four children's shows revolving around anthropomorphic tugboats.
* In the late 1980s, 13 episodes were made of TUGS , a series
depicting the life of tugboats in the 1920s.
* An American adaptation followed: Salty\'s Lighthouse .
* In the 1975's Soviet short animation musical film В порту/
In the sea port a tugboat sang a song: "Through a harbour area"
* One of the creators of that series went on to make Theodore
"Tugger" is a tugboat in the animated series
(Alphabetical by author)
* The children's book Scuffy the Tugboat , written by Gertrude Crampton and illustrated by Tibor Gergely and first published in 1946 as part of the Little Golden Books series, follows the adventures of a young toy tugboat who seeks a life beyond the confines of a tub inside his owner's toy store.
* The Dutch writer Jan de Hartog wrote numerous nautical novels, first in Dutch , then in English .
* The novel
Hollands Glorie , written prior to
World War II
Little Toot (1939), written and illustrated by
Hardie Gramatky ,
is a children's story of an anthropomorphic tugboat child, who wants
to help tow ships in a harbour near Hoboken . He's rejected by the
tugboat community and dejectedly drifts out to sea, where he
accidentally discovers a shipwrecked liner and a chance to prove his
South African Naval tugs perform a "ballet" when welcoming a new member of the fleet.
Since 1980, an annual tugboat ballet has been held in
TUGBOAT MOORS AT CONTAINER SHIP
The head tractor gets a thin line from the container ship *
The bow rope with precursor is taken from the container ship *
The stern rope is passed from the rear tractor *
A crew member of the container ship takes the stern rope and fastened it *
The stern tow rope is fixed to the container ship Manila Express, the drag is started
* Nautical portal
* ^ "How Pygmy Tugboats Dock a Giant Liner." Popular Science
Monthly, March 1930, p. 22-23.
* ^ Thorndike, Virginia L. (2004). On Tugboats: Stories of Work and
Life Aboard. Down East Books. pp. 14–16. ISBN 0-89272-565-6 .
* ^ Thoresen, Carl A. (2003). Port Designer's Handbook:
Recommendations and guidelines. Thomas Telford Books. p. 116. ISBN
* ^ Poulsen, B. Lund; et al. (1971). Teknisk Leksikon (in Danish).
2. København: A/S Forlaget for Faglitteratur København/Oslo. pp.
163–190. ISBN 87 573 0023 2 .
* ^ Bilinski, Marcie B.: "The Workhorse of the Waterways"
Massachusetts Office of Coastal Zone Management, Coastlines 2007
* ^ "Rotor Tug "RT Zoe"". Marineline.com. 13 September 2006.
Retrieved 19 August 2013.
* ^ "Western Marine to build tugboat, vessel for Ctg port". The
Independent. 4 June 2012. Retrieved 19 August 2013.
* ^ novatugnews. "Novatug.nl news". Novatug. Retrieved 2008-01-18.
* ^ novatugprod. "Novatug.nl product information". Novatug.
* ^ "Hollands glorie".
* Jane's Ocean Technology 1979-80 / Jane's Yearbooks, 1979 - ISBN 0-531-03902-1 . * On Tugboats: Stories of Work and Life Aboard / Virginia Thorndike - Down East Books, 2004. * Under Tow: A Canadian History of Tugs and Towing / Donal Baird - Vanwell Publishing, 277 p., 2003 - ISBN 1-55125-076-4 * Pacific Tugboats: / Gordon Newell - Superior Publishing Company 1957, Seattle Washington. * Primer of Towing / George H. Reid - Cornell Maritime Press, 1992.
* Lehman, Charles F. (2009). A riverman’s lexicon : in Lehman’s terms. Florissant, Mo.: J.R. Simpson & Associates. ISBN 978-0-9841503-0-4 . Nautical terminology specific to towboating on inland waterways.