Misplaced Pages

#611388

92-618: SS Baikal was an ice-breaking train ferry that linked the eastern and western portions of the Trans-Siberian Railroad across Lake Baikal . In early 1895 the construction of a ferry across the Lake Baikal began, following the proposal of the Minister of Transport Mikhail Khilkov . On 30 December 1895 a contract with Sir W G Armstrong Whitworth & Co Ltd in Newcastle upon Tyne

184-563: A combined propulsion power of 34,000 kW (46,000 hp). In Canada, diesel-electric icebreakers started to be built in 1952, first with HMCS Labrador (was transferred later to the Canadian Coast Guard), using the USCG Wind -class design but without the bow propeller. Then in 1960, the next step in the Canadian development of large icebreakers came when CCGS  John A. Macdonald

276-507: A conquest of the Low Countries with the shortest possible notice, to forestall the French, and prevent Allied air power from threatening the strategic Ruhr Area of Germany. It would also provide the basis for a long-term air and sea campaign against Britain. As much as possible of the border areas in northern France should be occupied. Germany's Blitzkrieg tactics rapidly overpowered

368-602: A heavy icebreaker must perform Operation Deep Freeze , clearing a safe path for resupply ships to the National Science Foundation ’s facility McMurdo in Antarctica. The most recent multi-month excursion was led by the Polar Star which escorted a container and fuel ship through treacherous conditions before maintaining the channel free of ice. Icebreakers are often described as ships that drive their sloping bows onto

460-535: A hull that is wider in the bow than in the stern. These so-called "reamers" increase the width of the ice channel and thus reduce frictional resistance in the aftship as well as improve the ship's maneuverability in ice. In addition to low friction paint, some icebreakers utilize an explosion-welded abrasion-resistant stainless steel ice belt that further reduces friction and protects the ship's hull from corrosion. Auxiliary systems such as powerful water deluges and air bubbling systems are used to reduce friction by forming

552-524: A lubricating layer between the hull and the ice. Pumping water between tanks on both sides of the vessel results in continuous rolling that reduces friction and makes progress through the ice easier. Experimental bow designs such as the flat Thyssen-Waas bow and a cylindrical bow have been tried over the years to further reduce the ice resistance and create an ice-free channel. Icebreakers and other ships operating in ice-filled waters require additional structural strengthening against various loads resulting from

644-417: A nuclear-powered icebreaking cargo ship, Sevmorput , which had a single nuclear reactor and a steam turbine directly coupled to the propeller shaft. Russia, which remains the sole operator of nuclear-powered icebreakers, is currently building 60,000 kW (80,000 hp) icebreakers to replace the aging Arktika class. The first vessel of this type entered service in 2020. A hovercraft can break ice by

736-451: A ship to be considered an icebreaker, it requires three traits most normal ships lack: a strengthened hull , an ice-clearing shape, and the power to push through sea ice . Icebreakers clear paths by pushing straight into frozen-over water or pack ice . The bending strength of sea ice is low enough that the ice breaks usually without noticeable change in the vessel's trim . In cases of very thick ice, an icebreaker can drive its bow onto

828-518: A short parallel midship to improve maneuverability in ice. However, the spoon-shaped bow and round hull have poor hydrodynamic efficiency and seakeeping characteristics, and make the icebreaker susceptible to slamming , or the impacting of the bottom structure of the ship onto the sea surface. For this reason, the hull of an icebreaker is often a compromise between minimum ice resistance, maneuverability in ice, low hydrodynamic resistance, and adequate open water characteristics. Some icebreakers have

920-641: A vertical axis. These thrusters improve propulsion efficiency, icebreaking capability and maneuverability of the vessel. The use of azimuth thrusters also allows a ship to move astern in ice without losing manoeuvrability. This has led to the development of double acting ships , vessels with the stern shaped like an icebreaker's bow and the bow designed for open water performance. In this way, the ship remains economical to operate in open water without compromising its ability to operate in difficult ice conditions. Azimuth thrusters have also made it possible to develop new experimental icebreakers that operate sideways to open

1012-582: A wide channel through ice. The steam-powered icebreakers were resurrected in the late 1950s when the Soviet Union commissioned the first nuclear-powered icebreaker , Lenin , in 1959. It had a nuclear-turbo-electric powertrain in which the nuclear reactor was used to produce steam for turbogenerators , which in turn produced electricity for propulsion motors. Starting from 1975, the Russians commissioned six Arktika -class nuclear icebreakers . Soviets also built

SECTION 10

#1732851374612

1104-655: A year, started being settled. The mixed ethnic group of the Karelians and the Russians in the North-Russia that lived on the shores of the Arctic Ocean became known as Pomors ("seaside settlers"). Gradually they developed a special type of small one- or two-mast wooden sailing ships , used for voyages in the ice conditions of the Arctic seas and later on Siberian rivers. These earliest icebreakers were called kochi . The koch's hull

1196-608: Is a sports event between Belgium and the Netherlands. Belgium separated in 1830 from the (northern) Netherlands. The new country took its name from Belgica , the Latinised name for the Low Countries, as it was known during the Eighty Years' War (1568–1648). The Low Countries were in that war divided in two parts. On one hand, the northern Federated Netherlands or Belgica Foederata rebelled against King Philip II of Spain ; on

1288-459: Is caused by the force of winds and tides on ice formations. The first boats to be used in the polar waters were those of the Eskimos . Their kayaks are small human-powered boats with a covered deck, and one or more cockpits, each seating one paddler who strokes a single or double-bladed paddle . Such boats have no icebreaking capabilities, but they are light and well fit to carry over the ice. In

1380-559: Is still Kingdom of the Netherlands , Koninkrijk der Nederlanden (plural). This name derives from the 19th-century origins of the kingdom which originally included present-day Belgium. In Dutch, and to a lesser extent in English, the Low Countries colloquially means the Netherlands and Belgium, sometimes the Netherlands and Flanders —the Dutch-speaking north of Belgium. For example, a Low Countries derby ( Derby der Lage Landen ),

1472-520: Is the blind poet Bernlef , from c.  800 , who sang both Christian psalms and pagan verses. Bernlef is representative of the coexistence of Christianity and Germanic polytheism in this time period. The earliest examples of written literature include the Wachtendonck Psalms , a collection of twenty five psalms that originated in the Moselle-Frankish region around the middle of

1564-451: Is to perform model tests in an ice tank . Regardless of the method, the actual performance of new icebreakers is verified in full scale ice trials once the ship has been built. In order to minimize the icebreaking forces, the hull lines of an icebreaker are usually designed so that the flare at the waterline is as small as possible. As a result, icebreaking ships are characterized by a sloping or rounded stem as well as sloping sides and

1656-598: The Austrian Netherlands . The United Kingdom of the Netherlands (1815–1830) temporarily united the Low Countries again before it split into the three modern countries of the Netherlands, Belgium and Luxembourg. During the early months of World War I (around 1914), the Central Powers invaded the Low Countries of Luxembourg and Belgium in what has been come to be known as the German invasion of Belgium . It led to

1748-643: The Baltic Sea , the Great Lakes and the Saint Lawrence Seaway , and along the Northern Sea Route , the main function of icebreakers is to escort convoys of one or more ships safely through ice-filled waters. When a ship becomes immobilized by ice, the icebreaker has to free it by breaking the ice surrounding the ship and, if necessary, open a safe passage through the ice field. In difficult ice conditions,

1840-490: The Dutch Revolt . Each of the provinces had its own laws, customs and political practices. The new policy, imposed from the outside, angered many inhabitants, who viewed their provinces as distinct entities. It and other monarchical acts, such as the creation of bishoprics and promulgation of laws against heresy , stoked resentments, which fired the eruption of the Dutch Revolt . After the northern Seven United Provinces of

1932-616: The European Union , the region's political grouping is still referred to as the Benelux (short for Belgium-Netherlands-Luxembourg). During the Roman Empire , the region contained a militarised frontier and contact point between Rome and Germanic tribes . The Low Countries were the scene of the early independent trading centres that marked the reawakening of Europe in the 12th century. In that period, they rivalled northern Italy as one of

SECTION 20

#1732851374612

2024-625: The Franco-Flemish School were highly sought by the leading classes of all Europe. In 1477 the Burgundian holdings in the area passed through an heiress— Mary of Burgundy —to the Habsburgs . Charles V, who inherited the territory in 1506, was named ruler by the States General and styled himself as Heer der Nederlanden ( lit.   ' Lord of the Netherlands ' ). He continued to rule

2116-511: The Kingdom of France or the Holy Roman Empire . While the further history the Low Countries can be seen as the object of a continual struggle between these two powers, the title of Duke of Lothier was coveted in the low countries for centuries. In the 14th and 15th century, separate fiefs came gradually to be ruled by a single family through royal intermarriage . This process culminated in

2208-543: The Mysovaya pier and sunk alongside. In 1920 the damaged hull was refloated and towed to Port Baikal. It remained untouched until at least 1926, and was later dismantled. There is a possibility that its lower hull, bow propeller, and part of the engines are still at the bottom of the lake at the mouth of the Angara River . This ferry article is a stub . You can help Misplaced Pages by expanding it . Icebreaker For

2300-658: The Rhine–Meuse–Scheldt delta and consisting today of the three modern " Benelux " countries: Belgium , Luxembourg , and the Netherlands (Dutch: Nederland , which is singular). Geographically and historically, the area can also include parts of France (such as Nord and Pas-de-Calais ) and the German regions of East Frisia , Guelders and Cleves . During the Middle Ages , the Low Countries were divided into numerous semi-independent principalities . Historically,

2392-558: The Roman provinces of Gallia Belgica and Germania Inferior . They were inhabited by Belgic and Germanic tribes . In the 4th and 5th century, Frankish tribes had entered this Roman region and came to run it increasingly independently. They came to be ruled by the Merovingian dynasty , under which dynasty the southern part (below the Rhine ) was re- Christianised . By the end of the 8th century,

2484-839: The Russian Civil War broke out Baikal was equipped with machine guns and cannons by the Bolsheviks . When Irkutsk surrendered to the White Army , Baikal sailed to the Mysovaya pier, the location of the Red Army headquarters. On 15 August 1918, the icebreaker was damaged by field artillery fire from the White Forces of the Czechoslovak Legion during the Battle of Lake Baikal . It was burnt at

2576-519: The St. Lawrence River . Icebreakers were built in order to maintain the river free of ice jam, east of Montréal . In about the same time, Canada had to fill its obligations in the Canadian Arctic. Large steam icebreakers, like the 80-metre (260 ft) CGS  N.B. McLean (1930) and CGS  D'Iberville (1952), were built for this dual use (St. Lawrence flood prevention and Arctic replenishment). At

2668-515: The United States Coast Guard , have a combined diesel-electric and mechanical propulsion system that consists of six diesel engines and three gas turbines . While the diesel engines are coupled to generators that produce power for three propulsion motors, the gas turbines are directly coupled to the propeller shafts driving controllable pitch propellers. The diesel-electric power plant can produce up to 13,000 kW (18,000 hp) while

2760-525: The Wind class . Research in Scandinavia and the Soviet Union led to a design that had a very strongly built short and wide hull, with a cut away forefoot and a rounded bottom. Powerful diesel-electric machinery drove two stern and one auxiliary bow propeller. These features would become the standard for postwar icebreakers until the 1980s. Since the mid-1970s, the most powerful diesel-electric icebreakers have been

2852-515: The 2000s, International Association of Classification Societies (IACS) has proposed adopting an unified system known as the Polar Class (PC) to replace classification society specific ice class notations. Since the Second World War , most icebreakers have been built with diesel-electric propulsion in which diesel engines coupled to generators produce electricity for propulsion motors that turn

SS Baikal - Misplaced Pages Continue

2944-672: The 9th and 10th centuries, the Viking expansion reached the North Atlantic , and eventually Greenland and Svalbard in the Arctic. Vikings , however, operated their ships in the waters that were ice-free for most of the year, in the conditions of the Medieval Warm Period . In the 11th century, in North Russia the coasts of the White Sea , named so for being ice-covered for over half of

3036-468: The German occupation of the two countries. However, the German advance into France was quickly halted, causing a military stalemate for most of the war. In the end, a total of approximately 56,000 people were killed in the invasion. During World War II , when Adolf Hitler 's gaze turned his strategy west toward France, the Low Countries were an easy route around the imposing French Maginot Line . He ordered

3128-631: The Low Countries formed a core part of a much expanded Francia and the Merovingians were replaced by the Carolingian dynasty . In 800, the Pope crowned and appointed Charlemagne Emperor of the re-established Roman Empire . After the death of Charlemagne , Francia was divided in three parts among his three grandsons. The middle slice, Middle Francia , was ruled by Lothair I , and thereby also came to be referred to as "Lotharingia" or "Lorraine". Apart from

3220-401: The Low Countries. Governor Mary of Hungary used both the expressions les pays de par deça and Pays d'Embas ("lands down here"), which evolved to Pays-Bas or Low Countries . Today the term is typically fitted to modern political boundaries and used in the same way as the term Benelux . The name of the country of the Netherlands has the same etymology and origin as

3312-497: The Soviet Union. Two shallow-draft Taymyr -class nuclear icebreakers were built in Finland for the Soviet Union in the late 1980s. In May 2007, sea trials were completed for the nuclear-powered Russian icebreaker NS 50 Let Pobedy . The vessel was put into service by Murmansk Shipping Company, which manages all eight Russian state-owned nuclear icebreakers. The keel was originally laid in 1989 by Baltic Works of Leningrad , and

3404-478: The ability of an icebreaker to propel itself onto the ice, break it, and clear the debris from its path successfully is essential for its safety. Prior to ocean-going ships, ice breaking technology was developed on inland canals and rivers using laborers with axes and hooks. The first recorded primitive icebreaker ship was a barge used by the Belgian town of Bruges in 1383 to help clear the town moat. The efforts of

3496-573: The altered bow Pilot ' s design from Britnev to make his own icebreaker, Eisbrecher I . The first true modern sea-going icebreaker was built at the turn of the 20th century. Icebreaker Yermak , was built in 1899 at the Armstrong Whitworth naval yard in England under contract from the Imperial Russian Navy . The ship borrowed the main principles from Pilot and applied them to

3588-596: The beginning of the 20th century, several other countries began to operate purpose-built icebreakers. Most were coastal icebreakers, but Canada, Russia, and later, the Soviet Union , also built several oceangoing icebreakers up to 11,000 tons in displacement. Before the first diesel-electric icebreakers were built in the 1930s, icebreakers were either coal- or oil-fired steam ships . Reciprocating steam engines were preferred in icebreakers due to their reliability, robustness, good torque characteristics, and ability to reverse

3680-558: The bow altered to achieve an ice-clearing capability (20° raise from keel line). This allowed Pilot to push herself on the top of the ice and consequently break it. Britnev fashioned the bow of his ship after the shape of old Pomor boats, which had been navigating icy waters of the White Sea and Barents Sea for centuries. Pilot was used between 1864 and 1890 for navigation in the Gulf of Finland between Kronstadt and Oranienbaum thus extending

3772-466: The contact between the hull of the vessel and the surrounding ice. As ice pressures vary between different regions of the hull, the most reinforced areas in the hull of an icegoing vessel are the bow, which experiences the highest ice loads, and around the waterline, with additional strengthening both above and below the waterline to form a continuous ice belt around the ship. Short and stubby icebreakers are generally built using transverse framing in which

SS Baikal - Misplaced Pages Continue

3864-422: The creation of the first polar icebreaker, which was able to run over and crush pack ice . The ship displaced 5,000 tons, and her steam- reciprocating engines delivered 10,000 horsepower (7,500 kW). The ship was decommissioned in 1963 and scrapped in 1964, making her one of the longest serving icebreakers in the world. In Canada, the government needed to provide a way to prevent flooding due to ice jam on

3956-636: The defences of Belgium, the Netherlands and Luxembourg. All three countries were occupied from May 1940 until early 1945. During the occupation, their governments were forced into exile in Britain. In 1944, they signed the London Customs Convention , laying the foundation for the eventual Benelux Economic Union , an important forerunner of the EEC (later the EU ). One of the Low Countries' earliest literary figures

4048-628: The diesel-electric powertrain is the preferred choice for icebreakers due to the good low-speed torque characteristics of the electric propulsion motors, icebreakers have also been built with diesel engines mechanically coupled to reduction gearboxes and controllable pitch propellers . The mechanical powertrain has several advantages over diesel-electric propulsion systems, such as lower weight and better fuel efficiency. However, diesel engines are sensitive to sudden changes in propeller revolutions, and to counter this mechanical powertrains are usually fitted with large flywheels or hydrodynamic couplings to absorb

4140-407: The direction of rotation quickly. During the steam era, the most powerful pre-war steam-powered icebreakers had a propulsion power of about 10,000 shaft horsepower (7,500 kW). The world's first diesel-electric icebreaker was the 4,330-ton Swedish icebreaker Ymer in 1933. At 9,000 hp (6,700 kW) divided between two propellers in the stern and one propeller in the bow, she remained

4232-565: The end of the Age of Sail also featured the egg-shaped form like that of Pomor boats, for example the Fram , used by Fridtjof Nansen and other great Norwegian Polar explorers . Fram was the wooden ship to have sailed farthest north (85°57'N) and farthest south (78°41'S), and one of the strongest wooden ships ever built. An early ship designed to operate in icy conditions was a 51-metre (167 ft) wooden paddle steamer , City Ice Boat No. 1 , that

4324-607: The first North American surface vessels to reach the North Pole. The vessel was originally scheduled to be decommissioned in 2000; however, a refit extended the decommissioning date to 2017. It is now planned to be kept in service through the 2020s pending the introduction of two new polar icebreakers, CCGS  Arpatuuq and CCGS  Imnaryuaq , for the Coast Guard. Russia currently operates all existing and functioning nuclear-powered icebreakers. The first one, NS Lenin ,

4416-511: The fixed pitch propellers. The first diesel-electric icebreakers were built with direct current (DC) generators and propulsion motors, but over the years the technology advanced first to alternating current (AC) generators and finally to frequency-controlled AC-AC systems. In modern diesel-electric icebreakers, the propulsion system is built according to the power plant principle in which the main generators supply electricity for all onboard consumers and no auxiliary engines are needed. Although

4508-403: The formerly Soviet and later Russian icebreakers Ermak , Admiral Makarov and Krasin which have nine twelve-cylinder diesel generators producing electricity for three propulsion motors with a combined output of 26,500 kW (35,500 hp). In the late 2020s, they will be surpassed by the new Canadian polar icebreakers CCGS  Arpatuuq and CCGS  Imnaryuaq , which will have

4600-503: The gas turbines have a continuous combined rating of 45,000 kW (60,000 hp). The number, type and location of the propellers depends on the power, draft and intended purpose of the vessel. Smaller icebreakers and icebreaking special purpose ships may be able to do with just one propeller while large polar icebreakers typically need up to three large propellers to absorb all power and deliver enough thrust. Some shallow draught river icebreakers have been built with four propellers in

4692-523: The heirs. By streamlining the succession law in all Seventeen Provinces and declaring that all of them would be inherited by one heir, Charles effectively united the Netherlands as one entity. After Charles' abdication in 1555, the Seventeen Provinces passed to his son, Philip II of Spain . The Pragmatic Sanction is said to be one example of the Habsburg contest with particularism that contributed to

SECTION 50

#1732851374612

4784-416: The hull and the ice, and allowed the icebreakers to penetrate thick ice ridges without ramming. However, the bow propellers are not suitable for polar icebreakers operating in the presence of harder multi-year ice and thus have not been used in the Arctic. Azimuth thrusters remove the need of traditional propellers and rudders by having the propellers in steerable gondolas that can rotate 360 degrees around

4876-423: The ice and break it under the weight of the ship. In reality, this only happens in very thick ice where the icebreaker will proceed at walking pace or may even have to repeatedly back down several ship lengths and ram the ice pack at full power. More commonly the ice, which has a relatively low flexural strength , is easily broken and submerged under the hull without a noticeable change in the icebreaker's trim while

4968-433: The ice breaking it. They were used in conjunction with teams of men with axes and saws and the technology behind them didn't change much until the industrial revolution. Ice-strengthened ships were used in the earliest days of polar exploration. 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

5060-409: The ice to break it under the weight of the ship. A buildup of broken ice in front of a ship can slow it down much more than the breaking of the ice itself, so icebreakers have 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 greater risk of damage than the vessel's hull, so

5152-594: The ice-breaking barge were successful enough to warrant the town purchasing four such ships. Ice breaking barges continued to see use during the colder winters of the Little Ice Age with growing use in the Low Country where significant amounts of trade and transport of people and goods took place. In the 15th century the use of ice breakers in Flanders ( Oudenaarde , Kortrijk , Ieper , Veurne , Diksmuide and Hulst )

5244-451: The icebreaker can also tow the weakest ships. Some icebreakers are also used to support scientific research in the Arctic and Antarctic. In addition to icebreaking capability, the ships need to have reasonably good open-water characteristics for transit to and from the polar regions, facilities and accommodation for the scientific personnel, and cargo capacity for supplying research stations on

5336-539: The icebreaker had been delivered for assembly to the village of Listvenichnoye . After three years it was completed and launched on 29 June [ O.S. 17 June] 1899. Before the Circum-Baikal Railway was opened in 1905, Baikal , and later also the Angara , carried two loads a day between piers at Baikal and Mysovaya . After the railway was completed, both ships continued to operate in reserve. When

5428-565: The level of ice strengthening in the ship's hull. It is usually determined by the maximum ice thickness where the ship is expected to operate and other requirements such as possible limitations on ramming. While the ice class is generally an indication of the level of ice strengthening, not the actual icebreaking capability of an icebreaker, some classification societies such as the Russian Maritime Register of Shipping have operational capability requirements for certain ice classes. Since

5520-425: The main languages used in secular city life. Historically, the term Low Countries arose at the Court of the Dukes of Burgundy , who used the term les pays de par deçà ("the lands over here") for the Low Countries as opposed to les pays de par delà ("the lands over there") for the Duchy of Burgundy and the Free County of Burgundy , which were part of their realm but geographically disconnected from

5612-412: The more spread-out hull loads. While the shell plating, which is in direct contact with the ice, can be up to 50 millimetres (2.0 in) thick in older polar icebreakers, the use of high strength steel with yield strength up to 500 MPa (73,000 psi) in modern icebreakers results in the same structural strength with smaller material thicknesses and lower steel weight. Regardless of the strength,

SECTION 60

#1732851374612

5704-417: The most densely populated regions of Western Europe. Guilds and councils governed most of the cities along with a figurehead ruler; interaction with their ruler was regulated by a strict set of rules describing what the latter could and could not expect. All of the regions mainly depended on trade, manufacturing and the encouragement of the free flow of goods and craftsmen. Dutch and French dialects were

5796-411: The most powerful Swedish icebreaker until the commissioning of Oden in 1957. Ymer was followed by the Finnish Sisu , the first diesel-electric icebreaker in Finland, in 1939. Both vessels were decommissioned in the 1970s and replaced by much larger icebreakers in both countries, the 1976-built Sisu in Finland and the 1977-built Ymer in Sweden. In 1941, the United States started building

5888-416: The name for the region Low Countries, due to "nether" meaning "low". In the Dutch language itself De Lage Landen is the modern term for Low Countries, and De Nederlanden (plural) is in use for the 16th century domains of Charles V , the historic Low Countries, while Nederland (singular) is the normal Dutch name for the country of the Netherlands. However, in official use, the name of the Dutch kingdom

5980-405: The nation's presence in the Arctic and Antarctic regions. As the icecaps in the Arctic continue to melt, there are more passageways being discovered. These possible navigation routes cause an increase of interests in the polar hemispheres from nations worldwide. The United States polar icebreakers must continue to support scientific research in the expanding Arctic and Antarctic oceans. Every year,

6072-446: The original coastal County of Flanders , which was within West Francia , the rest of the Low Countries were within the lowland part of this, " Lower Lorraine ". After the death of Lothair, the Low Countries were coveted by the rulers of both West Francia and East Francia . Each tried to swallow the region and to merge it with their spheres of influence. Thus, the Low Countries consisted of fiefs whose sovereignty resided with either

6164-434: The other, the southern Royal Netherlands or Belgica Regia remained loyal to the Spanish king. This divide laid the early foundation for the later modern states of Belgium and the Netherlands. The region politically had its origins in the Carolingian empire ; more precisely, most of the people were within the Duchy of Lower Lotharingia . After the disintegration of Lower Lotharingia, the Low Countries were brought under

6256-421: The political secession of the autonomous Dutch Republic (or "United Provinces") in the north, the term "Low Countries" continued to be used to refer collectively to the region. The region was temporarily united politically between 1815 and 1839, as the United Kingdom of the Netherlands , before this split into the three modern countries of the Netherlands, Belgium and Luxembourg. The Low Countries were part of

6348-401: The protected object. In the past, such operations were carried out primarily in North America, but today Arctic offshore drilling and oil production is also going on in various parts of the Russian Arctic. The United States Coast Guard uses icebreakers to help conduct search and rescue missions in the icy, polar oceans. United States icebreakers serve to defend economic interests and maintain

6440-419: The regions without access to the sea linked themselves politically and economically to those with access to form various unions of ports and hinterland , stretching inland as far as parts of the German Rhineland . Because of this, nowadays not only physically low-altitude areas, but also some hilly or elevated regions are considered part of the Low Countries, including Luxembourg and the south of Belgium. Within

6532-412: The resonance method. This causes the ice and water to oscillate up and down until the ice suffers sufficient mechanical fatigue to cause a fracture. Low Countries The Low Countries ( Dutch : de Lage Landen ; French : les Pays-Bas ), historically also known as the Netherlands (Dutch: de Nederlanden ), is a coastal lowland region in Northwestern Europe forming the lower basin of

6624-568: The rule of the House of Valois , who were the rulers of the Duchy of Burgundy . At the height of Burgundian influence, the Low Countries became the political, cultural, and economic centre of Northern Europe , noted for its crafts and luxury goods, notably early Netherlandish painting , which is the work of artists who were active in the flourishing cities of Bruges , Ghent , Mechelen , Leuven , Tournai and Brussels , all in present-day Belgium. Musicians of

6716-733: The rule of various lordships until they came to be in the hands of the Valois Dukes of Burgundy . Hence, a large part of the Low Countries came to be referred to as the Burgundian Netherlands . After the reign of the Valois Dukes ended, much of the Low Countries were controlled by the House of Habsburg . This area was referred to as the Habsburg Netherlands , which was also called the Seventeen Provinces up to 1581. Even after

6808-808: The seventeen declared their independence from Habsburg Spain in 1581, the ten provinces of the Southern Netherlands remained occupied by the Army of Flanders under Spanish service and are therefore sometimes called the Spanish Netherlands . In 1713, under the Treaty of Utrecht following the War of the Spanish Succession , what was left of the Spanish Netherlands was ceded to Austria and thus became known as

6900-399: The shell plating is stiffened with frames placed about 400 to 1,000 millimetres (1 to 3 ft) apart as opposed to longitudinal framing used in longer ships. Near the waterline, the frames running in vertical direction distribute the locally concentrated ice loads on the shell plating to longitudinal girders called stringers, which in turn are supported by web frames and bulkheads that carry

6992-484: The ship was launched in 1993 as NS Ural . This icebreaker is intended to be the sixth and last of the Arktika class. Today, most icebreakers are needed to keep trade routes open where there are either seasonal or permanent ice conditions. While the merchant vessels calling ports in these regions are strengthened for navigation in ice , they are usually not powerful enough to manage the ice by themselves. For this reason, in

7084-413: The ship. Bands of iron were wrapped around the outside. Sometimes metal sheeting was placed at the bows, at the 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 vise-like action

7176-511: The shore. Countries such as Argentina and South Africa , which do not require icebreakers in domestic waters, have research icebreakers for carrying out studies in the polar regions. As offshore drilling moves to the Arctic seas, icebreaking vessels are needed to supply cargo and equipment to the drilling sites and protect the drillships and oil platforms from ice by performing ice management, which includes for example breaking drifting ice into smaller floes and steering icebergs away from

7268-455: The so-called h - v -curve to determine the icebreaking capability of the vessel. It shows the speed ( v ) that the ship is able to achieve as a function of ice thickness ( h ). This is done by calculating the velocity at which the thrust from the propellers equals the combined hydrodynamic and ice resistance of the vessel. An alternative means to determine the icebreaking capability of a vessel in different ice conditions such as pressure ridges

7360-425: The steel used in the hull structures of an icebreaker must be capable of resisting brittle fracture in low ambient temperatures and high loading conditions, both of which are typical for operations in ice-filled waters. If built according to the rules set by a classification society such as American Bureau of Shipping , Det Norske Veritas or Lloyd's Register , icebreakers may be assigned an ice class based on

7452-468: The stern. Nozzles may be used to increase the thrust at lower speeds, but they may become clogged by ice. Until the 1980s, icebreakers operating regularly in ridged ice fields in the Baltic Sea were fitted with first one and later two bow propellers to create a powerful flush along the hull of the vessel. This considerably increased the icebreaking capability of the vessels by reducing the friction between

7544-512: The summer navigation season by several weeks. Inspired by the success of Pilot , Mikhail Britnev built a second similar vessel Boy ("Breakage" in Russian) in 1875 and a third Booy ("Buoy" in Russian) in 1889. The cold winter of 1870–1871 caused the Elbe River and the port of Hamburg to freeze over, causing a prolonged halt to navigation and huge commercial losses. Carl Ferdinand Steinhaus reused

7636-480: The territories as a multitude of duchies and principalities until the Low Countries were eventually united into one indivisible territory, the Seventeen Provinces , covered by the Pragmatic Sanction of 1549 , while retaining existing customs, laws, and forms of government within the provinces. The Pragmatic Sanction transformed the agglomeration of lands into a unified entity, of which the Habsburgs would be

7728-490: The torque variations resulting from propeller-ice interaction. The 1969-built Canadian polar icebreaker CCGS Louis S. St-Laurent was one of the few icebreakers fitted with steam boilers and turbogenerators that produced power for three electric propulsion motors. It was later refitted with five diesel engines, which provide better fuel economy than steam turbines. Later Canadian icebreakers were built with diesel-electric powertrain. Two Polar-class icebreakers operated by

7820-406: The vessel moves forward at a relatively high and constant speed. When an icebreaker is designed, one of the main goals is to minimize the forces resulting from crushing and breaking the ice, and submerging the broken floes under the vessel. The average value of the longitudinal components of these instantaneous forces is called the ship's ice resistance. Naval architects who design icebreakers use

7912-476: Was already well established. The use of the ice breaking barges expanded in the 17th century where every town of some importance in the Low Country used some form of icebreaker to keep their waterways clear. Before the 17th century the specifications of icebreakers are unknown. The specifications for ice breaking vessels show that they were dragged by teams of horses and the heavy weight of the ship pushed down on

8004-499: Was built for the city of Philadelphia by Vandusen & Birelyn in 1837. The ship was powered by two 250- horsepower (190 kW) steam engines and her wooden paddles were reinforced with iron coverings. With a rounded shape and strong metal hull, the Russian Pilot of 1864 was an important predecessor of modern icebreakers with propellers. The ship was built on the orders of merchant and shipbuilder Mikhail Britnev . She had

8096-452: Was completed at Lauzon, Quebec. A considerably bigger and more powerful ship than Labrador , John A.Macdonald was an ocean-going icebreaker able to meet the most rigorous polar conditions. Her diesel-electric machinery of 15,000 horsepower (11,000 kW) was arranged in three units transmitting power equally to each of three shafts. Canada's largest and most powerful icebreaker, the 120-metre (390 ft) CCGS  Louis S. St-Laurent ,

8188-471: Was delivered in 1969. Her original three steam turbine, nine generator, and three electric motor system produces 27,000 shaft horsepower (20,000 kW). A multi-year mid-life refit project (1987–1993) saw the ship get a new bow, and a new propulsion system. The new power plant consists of five diesels, three generators, and three electric motors, giving about the same propulsion power. On 22 August 1994 Louis S. St-Laurent and USCGC  Polar Sea became

8280-570: Was launched in 1957 and entered operation in 1959, before being officially decommissioned in 1989. It was both the world's first nuclear-powered surface ship and the first nuclear-powered civilian vessel . The second Soviet nuclear icebreaker was NS Arktika , the lead ship of the Arktika class . In service since 1975, she was the first surface ship to reach the North Pole , on August 17, 1977. Several nuclear-powered icebreakers were also built outside

8372-452: Was protected by a belt of ice-floe resistant flush skin-planking along the variable water-line, and had a false keel for on-ice portage . If a koch became squeezed by the ice-fields, its rounded bodylines below the water-line would allow for the ship to be pushed up out of the water and onto the ice with no damage. In the 19th century, similar protective measures were adopted to modern steam-powered icebreakers. Some notable sailing ships in

8464-452: Was signed for the parts of the icebreaking ferry (without woodwork and in disassembled state). Transport involved sending 7,000 crates with the disassembled from the UK to St Petersburg and then onward for assembly. The boilers, at some 20 tonnes were said to particularly challenging to transport and other parts of the ship went missing or were stolen during transport so had to be replaced. By June 1896

#611388