Ice navigation is a specialist area of

navigation Navigation is a field of study that focuses on the process of monitoring and controlling the motion, movement of a craft or vehicle from one place to another.Bowditch, 2003:799. The field of navigation includes four general categories: land navig ...

involving the use of maritime skills to determine and monitor the position of

ships A ship is a large vessel that travels the world's oceans and other navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally distinguished from boats, ...

in cold waters, where

ice Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 ° C, 32 ° F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally oc ...

is a hazard to the safety of navigation. The presence of

sea ice Sea ice arises as seawater freezes. Because ice is less density, dense than water, it floats on the ocean's surface (as does fresh water ice). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world' ...

requires a ship to exercise caution, for example by avoiding icebergs, slowly sailing through a

lead Lead () is a chemical element; it has Chemical symbol, symbol Pb (from Latin ) and atomic number 82. It is a Heavy metal (elements), heavy metal that is density, denser than most common materials. Lead is Mohs scale, soft and Ductility, malleabl ...

, or by working with an

icebreaker An icebreaker is a special-purpose ship or boat designed to move and navigate through ice-covered waters, and provide safe waterways for other boats and ships. Although the term usually refers to ice-breaking ships, it may also refer to smaller ...

to follow a course through the ice to a destination. Additionally ships must also deal with the extreme cold of the climate in regions such as the

poles Pole or poles may refer to: People *Poles (people), another term for Polish people, from the country of Poland * Pole (surname), including a list of people with the name * Pole (musician) (Stefan Betke, born 1967), German electronic music artist ...

; this involves removal of ice accumulation from the ship, as well as protecting the

crew A crew is a body or a group of people who work at a common activity, generally in a structured or hierarchy, hierarchical organization. A location in which a crew works is called a crewyard or a workyard. The word has nautical resonances: the ta ...

from the elements while working on the deck. Ships and their crews operating in ice will follow established rules of

seamanship Seamanship is the skill, art, competence (human resources), competence, and knowledge of operating a ship, boat or other craft on water. The'' Oxford Dictionary of English, Oxford Dictionary'' states that seamanship is "The skill, techniques, o ...

, as well as complying with national and international regulations such as the Polar Code. Ice strengthened vessels are typically used for navigation in ice regions, where additional hull strengthening and other design elements ensure operation in areas of high ice concentration.

Areas of ice navigation

Ice navigation occurs wherever a waterborne vessel transits through

. One of the more common regions for ice navigation is the

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

, where vessels visiting the

Baltic States The Baltic states or the Baltic countries is a geopolitical term encompassing Estonia, Latvia, and Lithuania. All three countries are members of NATO, the European Union, the Eurozone, and the OECD. The three sovereign states on the eastern co ...

will make their way through first year ice in the

winter Winter is the coldest and darkest season of the year in temperate and polar climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Dif ...

months, often with an

, or with ice reports, charts and data provided by meteorological offices. Other areas include the

Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, ...

, where increasing numbers of ships are transiting the region in the summer months for cruising and to transport cargo, as a result of oil and gas extraction in areas such as Yamal. The problems of increased shipping in polar regions presents additional challenges, including maritime safety concerns in the event that ice navigation is not carried out carefully. Ships will also pass through ice when navigating in the

Antarctic The Antarctic (, ; commonly ) is the polar regions of Earth, polar region of Earth that surrounds the South Pole, lying within the Antarctic Circle. It is antipodes, diametrically opposite of the Arctic region around the North Pole. The Antar ...

, although most ships are either research vessels or

cruise ship Cruise ships are large passenger ships used mainly for vacationing. Unlike ocean liners, which are used for transport, cruise ships typically embark on round-trip voyages to various ports of call, where passengers may go on Tourism, tours k ...

s that have been especially ice strengthened. Other significant maritime regions where ships will navigate through Ice include the

Saint Lawrence Seaway The St. Lawrence Seaway () is a system of rivers, locks, canals and channels in Eastern Canada and Northern United States that permits oceangoing vessels to travel from the Atlantic Ocean to the Great Lakes of North America, as far inland ...

, around

Greenland Greenland is an autonomous territory in the Danish Realm, Kingdom of Denmark. It is by far the largest geographically of three constituent parts of the kingdom; the other two are metropolitan Denmark and the Faroe Islands. Citizens of Greenlan ...

and the Canadian coast, the

North Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for ...

during iceberg season and through the

Northwest Passage The Northwest Passage (NWP) is the sea lane between the Atlantic and Pacific oceans through the Arctic Ocean, near the northern coast of North America via waterways through the Arctic Archipelago of Canada. The eastern route along the Arctic ...

Icing of superstructure

The accumulation of ice on the

superstructure A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. Aboard ships and large boats On water craft, the superstruct ...

is a dangerous phenomenon. When the temperature is below slight icing will occur at winds of 5 Bft, moderate icing at 7 Bft, and severe icing at 8 Bft. When sailing in fresh water, icing will occur from and below. The more common causes of ice formation on the superstructure are from spray by wave crests and ship-generated spray. Other possibilities are snow fall, sea fog, a drastic fall in ambient temperature and also freezing raindrops in contact with the cold steel. The heading of the vessel relative to the wind and seas will determine which parts of the superstructure will ice first. Icing can immobilise equipment such as anchors or cause a dangerous list if the windward side of the vessel ices more heavily.

Ice detection by radar

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

can be useful in detecting ice, but the returning signal which bounces off ice (even icebergs) is very faint, much lower than from ships. Conventional marine radars are designed for target detection and avoidance. Enhanced marine radars provide a higher definition image of the ice that the vessel is transmitting and will result in a much clearer image. This image can be used to identify the quantity and sort of ice that has to be dealt with. In standard radar, sea clutter affects the ability to see in the near vicinity of the vessel. An

X-band The X band is the designation for a band of frequency, frequencies in the microwave radio region of the electromagnetic spectrum. In some cases, such as in communication engineering, the frequency range of the X band is set at approximately 7.0� ...

radar set to a short pulse can give improved results.

References

Bibliography

* ''The Ice Navigation and Seamanship Handbook'' (2019). BIMCO and

Witherby Publishing Group Witherby Publishing Group, formerly known as Witherby Seamanship, is a technical publisher of maritime, nautical and navigation training, reference and regulatory materials. The company is the resulting merger of Witherby Books and Seaman ...

. . {{Seamanship Exploration of the Arctic Navigation

Areas of ice navigation

Icing of superstructure

Ice detection by radar

See also

References

Bibliography