FACTOID # 28: Austin, Texas has more people than Alaska.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Icebreaker" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Icebreaker
German icebreaker Polarstern

An icebreaker is a special purpose ship or boat designed to move and navigate through ice-covered waters. Although the term usually refers to icebreaking ships, it can also refer to smaller vessels (e.g., icebreaking boats that were used on the Canals of Great Britain in the days of commercial carrying). Icebreaker is a special purpose ship designed to move through ice. ... Image File history File links Ship breaking through the sea ice. ... Image File history File links Ship breaking through the sea ice. ... PFS Polarstern is a German research icebreaker. ... For other uses, see Ship (disambiguation). ... For other uses, see Boat (disambiguation). ... This article is about water ice. ... For online phenomenon of shipping, see Shipping (fandom). ... // See NO History of the British canal system for a more detailed history. ...


For a ship to be considered an icebreaker it requires three components: a strengthened hull, an ice-clearing shape, and the power to push through, none of which are possessed by most normal ships. A hull is the body or frame of a ship or boat. ...


To pass through ice-covered water, an icebreaker uses its great momentum and power to drive its bow up onto the ice, breaking the ice under the immense weight of the ship. Because a buildup of broken ice in front of a ship can slow it down much more than the breaking of the ice itself, the speed of the ship is increased by having a specially designed hull to direct the broken ice around or under the vessel . The external components of the ship's propulsion system (propellers, propeller shafts, etc.) are at even greater risk of damage than the vessel's hull, so the ability for an icebreaker to propel itself onto the ice, break it, and successfully clear the debris from its path is essential for its safety. Bow of the Cruise ship Spirit of Endeavour The bows of lifeboat 17-31 (Severn class) in Poole Harbour, Dorset, England The bow (pronounced to rhyme with how) is a nautical term that refers to the forward part of the hull of a ship or boat, the point that is... A propeller can be seen as a rotating fin in water or a wing in air. ...

An icebreaker in the Ross Sea

Contents

Image File history File links Metadata Size of this preview: 800 × 530 pixelsFull resolution (3811 × 2525 pixels, file size: 5. ... Image File history File links Metadata Size of this preview: 800 × 530 pixelsFull resolution (3811 × 2525 pixels, file size: 5. ... Map of Antarctica (click to enlarge) Ice in the Ross Sea, Antarctica The Ross Sea is a deep bay of the Southern Ocean in Antarctica between Victoria Land and Marie Byrd Land. ...

History

An early 20th century icebreaker — Sankt Erik launched in 1915. Note the shape of the bow, designed to ride up over the ice.
An early 20th century icebreaker — Sankt Erik launched in 1915. Note the shape of the bow, designed to ride up over the ice.

Even in the earliest days of polar exploration, ice-strengthened ships were used. These were originally wooden and based on existing designs, but reinforced, particularly around the waterline with double planking to the hull and strengthening cross members inside the ship. Bands of iron were wrapped around the outside. Sometimes metal sheeting was placed at the bows, stern and along the keel. Such strengthening was designed to help the ship push through ice and also to protect the ship in case it was "nipped" by the ice. Nipping occurs when ice floes around a ship are pushed against the ship trapping it as if in a vise and causing damage. This vice-like action is caused by the force of winds and tides on ice formations. Although such wind and tidal forces may be exerted many miles away, the ice transmits the force. ImageMetadata File history File links Download high resolution version (2048x1536, 1029 KB) The Sankt Erik is an icebreaker launched in 1915, and a museum ship attached to the Vasa Museum in Stockholm, Sweden. ... ImageMetadata File history File links Download high resolution version (2048x1536, 1029 KB) The Sankt Erik is an icebreaker launched in 1915, and a museum ship attached to the Vasa Museum in Stockholm, Sweden. ... The SS Sankt Erik is an icebreaker, and a museum ship attached to the Vasa Museum in Stockholm, Sweden. ... Polar exploration Polar Explorers Roald Amundsen Robert Falcon Scott Robert Peary Fridtjof Nansen Category: ... Waterline refers to an imaginary line marking the level at which ship or boat floats in the water. ...


The first known steam-powered icebreaker was the City Ice Boat No. 1, built by the city of Philadelphia in 1837. She was a wooden paddle steamer intended to break ice in the harbor. The first European steam-powered icebreakers were the Russian Pilot (1864) and the German Eisbrecher I (1871).[1] A paddle steamer, paddleboat, or paddlewheeler is a ship or boat propelled by one or more paddle wheels driven by a steam engine. ... Pilot (Russian: ) was a Russian icebreaker, often referred to as the worlds first steam-powered icebreaker. ...


At the beginning of the 20th century several countries began to operate purpose-built icebreakers. Most were coastal icebreakers, but Russia and later the Soviet Union also built several oceangoing icebreakers of around 10,000 tonnes displacement. Several technological advances were introduced over the years, but it was not until the introduction of nuclear power in the Soviet icebreaker Lenin in 1959 that icebreakers developed their full potential. This article is about applications of nuclear fission reactors as power sources. ... Icebreaker Lenin Lenin was the first nuclear surface ship in the world. ...


Function of icebreakers

Icebreakers are needed to keep trade routes open where there are either seasonal or permanent ice conditions. Icebreakers are expensive to build and very expensive to run, whether the icebreaker is powered by gas turbines, diesel-electric powerplant or nuclear energy. They are uncomfortable to travel in on the open sea: almost all of them have thick, rounded keels, and with no protuberances for stability, they can roll even in light seas. They are also uncomfortable to travel in when breaking through continuous thick ice due to constant motion, noise, and vibration. This machine has a single-stage centrifugal compressor and turbine, a recuperator, and foil bearings. ... A number of vehicles use a diesel-electric powerplant for providing locomotion. ... Nuclear icebreaker Yamal on its way to the North Pole in August 2001 A nuclear powered icebreaker is a purpose-built ship for use in waters continuously covered with ice. ... Look up stability in Wiktionary, the free dictionary. ...


A modern icebreaker typically has shielded propellers both at the bow and at the stern, as well as side thrusters; pumps to move water ballast from side-to-side; and holes on the hull below the waterline to eject air bubbles, all designed to allow an icebreaker stuck amidst thick ice to break free. Many icebreakers also carry aircraft (formerly seaplanes but now helicopters) to assist in reconnaissance and liaison. A DeHavilland Single Otter floatplane in Harbour Air livery. ... For other uses, see Helicopter (disambiguation). ...


Design and construction

Icebreakers are constructed with a double hull and watertight compartments in case of a breach. The ship's hull is thicker than normal, especially at the bow, stern, and waterline, using special steel that has optimum performance at low temperatures. The thicker steel at the waterline typically extends about 1 m above and below the waterline, and is reinforced with extra internal ribbing, sometimes twice the ribbing of a normal ship. The bow is rounded rather than pointed, allowing the vessel to ride up over the ice, breaking it with the weight of the vessel. The hull has no appendages likely to be damaged by the ice, and the rudder and propeller are protected by the shape of the hull. The propeller blades are strengthened, and the vessel has the ability to inspect and replace blades while at sea.[2] A double hull is a ship hull design and construction method where the bottom and sides of the ship have two complete layers of watertight hull surface: one outer layer forming the normal hull of the ship, and a second inner hull which is somewhat further into the ship, perhaps...


Recent advances

USCGC Healy (WAGB-20)

The optimal shape for moving through ice makes icebreakers uncomfortable in open water and gives them poor fuel efficiency. Image File history File links USCGC_Healy. ... Image File history File links USCGC_Healy. ... Coast Guard shield The United States Coast Guard is the coast guard of the United States. ... For other uses see cutter (disambiguation) An American-looking gaff cutter with a genoa jib set This French yawl has a gaff topsail set. ...


Icebreakers tend to roll side to side to the discomfort of the crew. Some new icebreakers such as the USCGC Healy make use of anti-roll tanks. Anti-roll tanks use computer controlled pumps to rapidly shift ballast water side-to-side to keep the vessel upright. The USCGC Healy is a research icebreaker put into commission in 1999 by the U.S. Coast Guard. ...


A greater concern is how well a ship cuts through waves. The ability of a ship to cut through waves can greatly affect its fuel efficiency and even its safety in a storm. Most ships use a sharp or bulbous bow to cut through waves and help prevent waves from slamming the bow of the ship. However, icebreakers have a round sled-like bow. They tend to slam into waves, which can be risky in high seas. The bulbous bow of the U.S. Navy carrier USS Ronald Reagan is clearly visible in this photograph. ...


Recent advances in ship propulsion have produced new experimental icebreakers. Electrically driven propellers are mounted to steerable pods under the ship. These Azimuthing Podded Propulsors, or Azi-pods, improve fuel efficiency, ship steering, ship docking, and remove the need for rudders. Azipods also allow a ship to travel backwards as easily as it travels forwards. The double acting icebreaker is unique because its stern is shaped like an icebreaker's bow. Normally traveling forward, a double acting icebreaker uses a conventional ship bow for a more comfortable ride. When ice is encountered, the ship turns around and travels backwards through the ice. The MT Mastera and MT Tempera are two vessels using this new technology. Siemens Schottel azimuth thrusters An Azimuth thruster is a configuration of ship propellers placed in pods that can be rotated in any horizontal direction. ... The MT Mastera was finished in 2002. ... The MT Tempera is an ocean-going icebreaking tanker that was finished in 2002. ...


In the 1980s hovercraft were shown to be effective as icebreakers on rivers. Instead of displacing or crushing the ice from above, they work by injecting a bubble of air under the ice sheet, causing it to break off and be swept downstream by the current. The purpose is usually not to provide navigation channels but rather to prevent ice dams from forming on bridge structures, thus damaging them and causing local flooding. For the band, see Hovercraft (band). ...


See also

Oil tanker SS Manhattan (The entry SS Manhattan is for an 1930s ocean liner. ... Nuclear icebreaker Yamal on its way to the North Pole in August 2001 A nuclear powered icebreaker is a purpose-built ship for use in waters continuously covered with ice. ...

References

  1. ^ Bruun P (1989). Port Engineering, Volume 1: Harbor Planning, Breakwaters, and Marine Terminals, 4th ed., Gulf Publishing Company, p. 1375. ISBN 0872018431. 
  2. ^ Icebreakers and ice strengthened ships. Retrieved on 2007-11-25.

Year 2007 (MMVII) is the current year, a common year starting on Monday of the Gregorian calendar and the AD/CE era in the 21st century. ... is the 329th day of the year (330th in leap years) in the Gregorian calendar. ...

External links

Wikimedia Commons has media related to:
Icebreakers
Image File history File links Commons-logo. ...

  Results from FactBites:
 
Icebreaker - definition of Icebreaker in Encyclopedia (681 words)
Icebreaker is also the title of a James Bond novel by John Gardner.
Icebreakers are expensive to build and very expensive to run, whether the icebreaker is powered by gas turbines, or is a nuclear powered icebreaker.
Icebreakers with the round, sled-like bow used to ride up on the ice tend to slam into waves and can be a risk in high seas.
Icebreaker - Wikipedia, the free encyclopedia (1008 words)
Essential to an icebreaking vessel is the ability to propel itself onto the ice, breaking it, and then successfully clearing the ice debris from its path.
Icebreakers are expensive to build and very expensive to run, whether the icebreaker is powered by gas turbines, diesel-electric powerplant or nuclear energy.
A modern icebreaker typically has shielded propellers both at the bow and at the stern, as well as side thrusters; pumps to move water ballast from side to side; and holes on the hull below the waterline to eject water bubbles, all designed to allow an icebreaker stuck amidst thick ice to break free.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m