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small, strongly built vessel, used to guide large oceangoing ships into and out of port and to tow barges, dredging and salvage equipment, and disabled vessels. Tugboats range in overall length from 70 to 210 ft (21–64 m), and their engines generate from 750 to 3,000 horsepower. Steam power dominated tugboat design until diesel and diesel-electric drives were developed. Most tugs are built of wood or metal-sheathed wood; the resiliency of a wooden hull prevents damage to both tugboat and vessel in berthing operations.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



a self-propelled ship used for towing nonself-propelled vessels, rafts, and other floating structures. Tugboats are used on the ocean, on rivers, on lakes, and in harbors. They are divided according to their functions into the following categories: towing tugboats, which pull other vessels by means of a towline; maneuvering tugboats, which aid ships in the process of docking and mooring; pusher tugboats, which push ships rather than pull them; and rescue tugboats, which assist ships disabled on the high seas and tow them to a safe harbor.

A tugboat’s function determines the pull on its tow hook and the power of its main engines. Harbor tugboats have engines of up to 150 kilowatts (kW), or 200 horsepower; modern rescue tugboats have engines of 6,000-7,000 kW (8,000-9,000 horsepower) and more. Tugboats are fitted with towing gear, which is the aggregate of equipment used for securing and paying out the towline with which the tug tows other ships, rafts, and so on. This equipment consists of a tow hook, attached to a hinge and rotating around the towing rail; towing arches; and trunnion caps (or shackles). The hook is often replaced by a towing winch, which maintains constant tension on the towline. The tow hook provides long-range payout of the towline; on harbor tugboats it provides automatic reduction in the height of the suspension in case of a change from longitudinal to lateral towing pull in order to prevent capsizing.


The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


(naval architecture)
A powerful, strongly built boat with shaped hull and bow, designed to tow or push other vessels or barges in harbors, on inland waterways, and at sea.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The contract will have a duration period of 15 years with the delivery of the first tugboats expected on August 1, 2020.
They started providing tugboats, barges, and steam-powered boats.
The length of the tugboat exceeds 30 meters, width - about 12 meters, draft -- up to 3.5 meters.
The court decided that those new-fangled radios were inexpensive and easily available, so as technology marched forward, the tugboat industry was required to march along with it.
With the help of the job bidding module from the software development specialists at Tugboat Software, companies can project their staffing level plans and automate employee response.
The network is currently in closed beta-testing in San Francisco and will be launched publicly at the beginning of 2013.Country: USASector: IT/Online ServicesTarget: Koozoo IncBuyer: New Enterprise Associates Inc , Michael Covarrubias, Tugboat Ventures, Dave MoellenhoffType: VCStatus: ClosedComment: Deal size refers to combined investment.
THE Edward O'Grady-trained Tugboat should prove tough to beat when he reverts to the flat at Gowran Park this evening.
The man, who last night had not been named but is from Derby, is unaccounted for after his tugboat got into trouble on Monday morning in the area of the Bay of Biscay.
The man, who has not been named but is from Derby, is unaccounted for after his tugboat got into trouble on Monday morning in the area of the Bay of Biscay.
CAIRO: Three people were killed and a dozen others injured when a tugboat engine exploded in Egypt's Suez Canal on Monday, security officials said.
TELECOMWORLDWIRE-September 1, 2011-QAD to offer customers Tugboat's Roundtable Total Software Management System(C)1994-2011 M2 COMMUNICATIONS http://www.m2.com
Mobile and fixed-site remote communications solutions provider Stratos Global announced on Friday that it is deploying the Inmarsat FleetBroadband satellite communications service on six deep-sea tugboats in tugboat operator Fairplay Towage's fleet.