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25-733: The Radium Gilbert was a tugboat built for transporting supplies to, and ore from, the radium and uranium mines in Canada 's Northwest Territories . Like the other tugs in the Radium Line she was steel-hulled. She was named after Gilbert Labine , the prospector who discovered radioactive ore where Port Radium was built. She was built in Vancouver , in 1946 disassembled, so she could be shipped by rail to Waterways, Alberta . Like all vessels assembled in Waterways that operated on

50-408: A migration period of 12 years to ensure that ships were given reasonable economic safeguards, since port and other dues are charged according to ship's tonnage. Since 18 July 1994 the gross and net tonnages, dimensionless indices calculated from the total moulded volume of the ship and its cargo spaces by mathematical formulae , have been the only official measures of the ship's tonnage. However,

75-445: A minimum horsepower or bollard pull, determined by the size of the escorted vessel. Most ports will have a number of tugs that are used for other purposes than ship assist, such as dredging operations, bunkering ships, transferring liquid products between berths, and cargo ops. These tugs may also be used for ship assist as needed. Modern ship assist tugs are "omni directional tugs" that employ propellers that can rotate 360 degrees without

100-682: A port in Hamburg. 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. The Tugboat Roundup is a gathering of tugboats and other vessels in celebration of maritime industry. The Waterford Tugboat Roundup is held in the late summer at the confluence of the Hudson and Mohawk Rivers in Waterford, New York. The tugs featured are river tugs and other tugs re-purposed to serve on

125-409: A rudder, like azimuthal stern drives (ASD), azimuthal tractor drives (ATD), Rotor tugs (RT) or cycloidal drives (VSP)(as described below). River tugs are also referred to as towboats or pushboats. Their hull designs would make open ocean operations 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

150-407: Is a ship's cargo volume capacity expressed in "register tons", one of which equals to a volume of 100 cubic feet (2.83 m ). It is calculated by subtracting non-revenue-earning spaces i.e. spaces not available for carrying cargo, for example engine rooms, fuel tanks and crew quarters, from the ship's gross register tonnage . Net tonnage is thus used in situations where a vessel's earning capacity

175-471: 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. The cycloidal propeller is a circular plate mounted on

200-600: Is a tugboat in the animated series South Park . He appears in the episode " The New Terrance and Phillip Movie Trailer " as a sidekick for Russell Crowe in a fictitious television series entitled Fightin' Round The World with Russell Crowe . 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. (Alphabetical by author) Net Register Tonnage Net register tonnage ( NRT , nrt , n.r.t. )

225-649: Is important, rather than its mere size. Net register tonnage is not a measure of the weight of the ship or its cargo, and should not be confused with terms such as deadweight tonnage or displacement . Gross and net register tonnages were replaced by gross tonnage and net tonnage , respectively, when the International Maritime Organization (IMO) adopted The International Convention on Tonnage Measurement of Ships on 23 June 1969. The new tonnage regulations entered into force for all new ships on 18 July 1982, but existing vessels were given

250-448: 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. In some ports there is a requirement for certain numbers and sizes of tugboats for port operations with gas tankers . 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

275-646: Is the carousel tug , winner of the Maritime Innovation Award at the Dutch Maritime Innovation Awards Gala in 2006. 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. Since the towing point rotates freely, the tug is very difficult to capsize. Vintage tugboat races have been held annually in Olympia, Washington , since 1974 during

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300-605: The Mackenzie River , and its tributaries, after she was reassembled she first proceeded downstream to Lake Athabasca , and down the Slave River , to the portage at Fort Smith . Large tractors towed even large cargo overland around large rapids there. The Radium Gilbert spent her operational life 1946 to 1980 on Great Bear Lake . She ran aground near Deline , the small community at the outlet for Great Bear Lake . Her wreck remained radioactive decades after she

325-522: The Z-drive or ( azimuth thruster ) was developed. Although sometimes referred to as the Aquamaster or Schottel system, many brands exist: Steerprop , Wärtsilä , Berg Propulsion , etc. These propulsion systems are used on tugboats designed for tasks such as ship docking and marine construction. Conventional propeller/rudder configurations are more efficient for port-to-port towing. The Kort nozzle

350-546: 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. Tugboats are highly manoeuvrable, and various propulsion systems have been developed to increase manoeuvrability and increase safety. The earliest tugs were fitted with paddle wheels , but these were soon replaced by propeller-driven tugs. Kort nozzles (see below) have been added to increase thrust-to-power ratio. This

375-726: The New York State Canal System. Tugboat Annie was the subject of a series of Saturday Evening Post magazine stories featuring the female captain of the tugboat Narcissus in Puget Sound , later featured in the films Tugboat Annie (1933), Tugboat Annie Sails Again (1940) and Captain Tugboat Annie (1945). The Canadian television series The Adventures of Tugboat Annie was filmed in 1957. To date, there have been four children's shows revolving around anthropomorphic tugboats. "Tugger"

400-931: The Olympia Harbor Days Maritime Festival Tugboat races are held annually on Elliott Bay in Seattle , on the Hudson River at the New York Tugboat Race , the Detroit River , and the Great Tugboat Race and Parade on the St. Mary's River . Since 1980, an annual tugboat ballet has been held in Hamburg harbour on the occasion of the festival commemorating the anniversary of the establishment of

425-517: The barge, often with large pushing knees. The first tugboat, Charlotte Dundas , was built by William Symington in 1801. It had a steam engine and paddle wheels and was used on rivers in Scotland. Paddle tugs proliferated thereafter and were a common sight for a century. In the 1870s schooner hulls were converted to screw tugs. Compound steam engines and scotch boilers provided 300 Indicated Horse Power. Steam tugs were put to use in every harbour of

450-425: The collective pitch control and cyclic in a helicopter. Tugboat fenders are made of high-abrasion-resistance rubber with good resilience properties. They are very popular with small port craft owners and tug owners. These fenders are generally made from cut pieces of vehicle tires strung together. Often the fendering on the sides of the tug is composed of large heavy equipment or aircraft tires attached to or hung on

475-546: The other surviving vessels of the Radium line were found to be free of contamination. But the Radium Gilbert was significantly contaminated—particularly her showers. 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

500-430: 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, tugboat engines often feature two of each critical part for redundancy. A tugboat is typically rated by its engine's power output and its overall bollard pull . The largest commercial harbour tugboats in

525-501: The side of the tug. Some fendering is compression moulded in high-pressure thermic-fluid-heated moulds and have excellent seawater resistance, but are not widely used owing to the cost. Tugboat bow fenders are also called beards or bow puds. In the past they were made of rope for padding to protect the bow, but rope rendering is almost never seen in recent times. Other types of tugboat fender include Tug cylindrical fender, W fender, M fender, D fender, and others. A recent Dutch innovation

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550-400: The underside of the hull, rotating around a vertical axis with a circular array of vertical blades (in the shape of hydrofoils ) that protrude out of the bottom of the ship. Each blade can rotate itself around a vertical axis. The internal mechanism 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, similar to

575-470: The world towing and ship berthing. Tugboat diesel engines typically produce 500 to 2,500 kW ( ~ 680 to 3,400 hp ), but larger boats (used in deep waters) can have power ratings up to 20,000 kW (~ 27,200 hp) . 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 engines are often

600-483: Was followed by the nozzle-rudder, which omitted the need for a conventional rudder . 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. In the late 1950s,

625-408: Was used to ship radioactive ore. She was dismantled, and removed, in 2003, after lying grounded, for decades. By that time the population of Deline understood the toxic legacy of the trade in radioactive ore, and the nearby wreck was a painful reminder. In 2005 Atomic Energy of Canada published a study of the toxic legacy of the mining of radioactive ore at Port Radium. According to the report all

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