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113-447: USS Glacier (AGB-4) (later USCGC Glacier (WAG/WAGB-4) ) was a U.S. Navy, then U.S. Coast Guard icebreaker which served in the first through fifteenth Operation Deep Freeze expeditions. Glacier was the first icebreaker to make her way through the frozen Bellingshausen Sea , and most of the topography in the area is named for her crew members. When built, Glacier had the largest capacity single armature DC motors ever installed on

226-530: A day apart, with Gamme starting first, but completing according to plan the last few kilometers together. As Gamme traveled alone he thus simultaneously became the first to complete the task solo. On 28 December 2018, Captain Lou Rudd became the first Briton to cross the Antarctic unassisted via the south pole, and the second person to make the journey in 56 days. On 10 January 2020, Mollie Hughes became

339-498: 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 the end of the Age of Sail also featured the egg-shaped form like that of Pomor boats, for example

452-460: A higher elevation). The South Pole is at an altitude of 9,200 feet (2,800 m) but feels like 11,000 feet (3,400 m). Centripetal force from the spin of the planet throws the atmosphere toward the equator. The South Pole is colder than the North Pole primarily because of the elevation difference and for being in the middle of a continent. The North Pole is a few feet from sea level in

565-535: 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

678-524: 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

791-417: 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

904-561: 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 the altered bow Pilot ' s design from Britnev to make his own icebreaker, Eisbrecher I . The first true modern sea-going icebreaker

1017-520: 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, 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

1130-432: A ship. Glacier was capable of breaking ice up to 20 feet (6.1 m) thick, and of continuous breaking of 4-foot (1.2 m) thick ice at 3 knots (5.6 km/h; 3.5 mph). Named for Glacier Bay , Alaska , USS Glacier was launched on 27 August 1954 at Ingalls Shipbuilding Corp., Pascagoula, Mississippi , sponsored by Mrs. Roscoe F. Good; and commissioned on 27 May 1955, CDR. E.H. Mayer USN, Commanding. Glacier

1243-518: 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

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1356-403: 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 the ice to break it under the weight of

1469-641: 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

1582-593: 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

1695-519: Is because the US flies its resupply missions (" Operation Deep Freeze ") out of McMurdo Station , which is supplied from Christchurch , New Zealand. Due to its exceptionally harsh climate, there are no native resident plants or animals at the South Pole. Off-course south polar skuas and snow petrels are occasionally seen there. In 2000 it was reported that microbes had been detected living in

1808-585: Is currently buried beneath the snow and ice in the vicinity of the Pole. It has been designated a Historic Site or Monument (HSM 80), following a proposal by Norway to the Antarctic Treaty Consultative Meeting . The precise location of the tent is unknown, but based on calculations of the rate of movement of the ice and the accumulation of snow, it is believed, as of 2010, to lie between 1.8 and 2.5 km (1.1 and 1.5 miles) from

1921-667: Is designed and fabricated each year by staff at the site. The Ceremonial South Pole is an area set aside for photo opportunities at the South Pole Station . It is located some meters from the Geographic South Pole, and consists of a metallic sphere on a short barber pole, surrounded by the flags of the original Antarctic Treaty signatory states . The tent was erected by the Norwegian expedition led by Roald Amundsen on its arrival on 14 December 1911. It

2034-428: Is east, and counterclockwise is west, opposite to the North Pole . The Geographic South Pole is presently located on the continent of Antarctica , although this has not been the case for all of Earth's history because of continental drift . It sits atop a featureless, barren, windswept and icy plateau at an altitude of 2,835 m (9,301 ft) above sea level, and is located about 1,300 km (810 mi) from

2147-452: Is not adequate for very precise work. The geographic coordinates of the South Pole are usually given simply as 90°S, since its longitude is geometrically undefined and irrelevant. When a longitude is desired, it may be given as 0°. At the South Pole, all directions face north. For this reason, directions at the Pole are given relative to "grid north", which points northward along the prime meridian . Along tight latitude circles, clockwise

2260-595: Is one of the two points where Earth's axis of rotation intersects its surface. Situated on the continent of Antarctica , it is the site of the United States Amundsen–Scott South Pole Station , which was established in 1956 and has been permanently staffed since that year. The Geographic South Pole is distinct from the South Magnetic Pole , the position of which is defined based on Earth's magnetic field . The South Pole

2373-456: Is partially buried due to snow storms, and the entrance to the dome had to be regularly bulldozed to uncover it. More recent buildings are raised on stilts so that the snow does not build up against their sides. In most places on Earth, local time is determined by longitude , such that the time of day is more-or-less synchronised to the perceived position of the Sun in the sky (for example, at midday

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2486-573: Is the center of the Southern Hemisphere . 90°S 0°E  /  90°S 0°E  / -90; 0 For most purposes, the Geographic South Pole is defined as the southern point of the two points where Earth's axis of rotation intersects its surface (the other being the Geographic North Pole ). However, Earth's axis of rotation is actually subject to very small "wobbles" ( polar motion ), so this definition

2599-529: Is the only icebreaker built in the Glacier class, and was in U.S. Navy service for 11 years, and U.S. Coast Guard service for 21 years. Glacier was essentially an improved Wind-class icebreaker , larger and more powerful. Like them, her entire hull was designed for great strength. With a relatively short length in proportion to the great power developed, her bow had the characteristic sloping forefoot that enabled her to ride up on heavy ice and break it with

2712-451: 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

2825-507: 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 was built for the city of Philadelphia by Vandusen & Birelyn in 1837. The ship

2938-655: The Arctic Circle , International Dateline , Equator , and Antarctic Circle lines all within six weeks, attaining "Square Knot Sailor" status in that short time frame. Glacier and other USCG icebreakers opened up the McMurdo shipping lanes, then returned to Port Lyttelton. At that time an experimental navigational satellite (NavSat) system was installed in Glacier by the Applied Physics Lab of Johns Hopkins University , to allow precise positioning in

3051-527: 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 was protected by a belt of ice-floe resistant flush skin-planking along the variable water-line, and had

3164-516: The Chukchi Sea north of Cape Lisbourne, Alaska , to aid in the rescue of USCGC  Northwind , beset in Arctic ice. The Canadian icebreaker CCGS  John A. MacDonald had freed Northwind by the time of Glacier ' s arrival. Glacier departed Arctic waters to sail to Port Lyttelton, to start Operation Deep Freeze 1967–68. Due to the Northwind rescue trip, Glacier had crossed

3277-624: The International Geophysical Year and has been continuously staffed since then by research and support personnel. After Amundsen and Scott, the next people to reach the South Pole overland (albeit with some air support) were Edmund Hillary (4 January 1958) and Vivian Fuchs (19 January 1958) and their respective parties, during the Commonwealth Trans-Antarctic Expedition . There have been many subsequent expeditions to arrive at

3390-555: The Royal New Zealand Navy (RNZN) through the ice pack to the two Antarctic bases. In January 1957 she led two cargo ships into Vincennes Bay where the last of the seven American bases for the International Geophysical Year was to be constructed. Glacier departed Wilkes Station on 17 February 1957 for the United States via Melbourne , Australia when the operation was completed. During "Deep Freeze III" and

3503-526: 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

USS Glacier (AGB-4) - Misplaced Pages Continue

3616-429: The 120-metre (390 ft) CCGS  Louis S. St-Laurent , 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

3729-630: The 1976-built Sisu in Finland and the 1977-built Ymer in Sweden. In 1941, the United States started building 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

3842-529: 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

3955-545: The 5-inch guns were also removed. Only the M2 Browning machine guns , M60 machine guns and small arms were retained for law enforcement purposes. During 1973, she and her helicopters were painted red for improved Arctic visibility. In 1975, Glacier was trapped in ice in Antarctica for six days, finally breaking free and escaping into the waters of Antarctic Sound on 10 March 1975. "She backed and rammed her way to

4068-518: 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 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

4181-676: The Amundsen–Scott South Pole Station was −12.3 °C (9.9 °F) on Christmas Day, 2011, and the lowest was −82.8 °C (−117.0 °F) on 23 June 1982 (for comparison, the lowest temperature directly recorded anywhere on earth was −89.2 °C (−128.6 °F) at Vostok Station on 21 July 1983, though −93.2 °C (−135.8 °F) was measured indirectly by satellite in East Antarctica between Dome A and Dome F in August 2010 ). Mean annual temperature at

4294-699: The Antarctic, home of over 50,000 of the large birds. Glacier then sped to the assistance of the Belgian expedition ship RV Polarhav near Breid Bay, halfway around the Antarctic continent from the Ross Sea . For "Operation Deep Freeze 5" in 1959–1960, Glacier sailed to McMurdo and then on an exploration of the Bellingshausen Sea . In late February 1960 Glacier raced to assist Argentine Navy icebreaker ARA  General San Martín and Danish cargo ship MV  Kista Dan . When this rescue mission

4407-716: 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 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

4520-533: The Canadian development of large icebreakers came when CCGS  John A. Macdonald 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,

4633-469: The Coast Guard. Russia currently operates all existing and functioning nuclear-powered icebreakers. The first one, NS Lenin , 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 ,

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4746-657: The Geographic South Pole were the Norwegian Roald Amundsen and his party on 14 December 1911. Amundsen named his camp Polheim and the entire plateau surrounding the Pole King Haakon VII Vidde in honour of King Haakon VII of Norway . Robert Falcon Scott returned to Antarctica with his second expedition, the Terra Nova Expedition , initially unaware of Amundsen's secretive expedition. Scott and four other men reached

4859-464: The IGY of 1957–1958, Glacier participated as a launching platform for " rockoon " tests during which balloon-lifted rockets gathered information of interest to the "Explorer" space satellite program . Additionally, Glacier continued her usual icebreaking and escort duties, and conducted oceanographic surveys in the Ross Sea . In the summer of 1958, Glacier provided ice-escort for "Operation Sunec" for

4972-613: The NavSat system. These stations were to be revisited in three years, and the current meters sonic-released for data collection. The heavy fast ice in the Weddell Sea thwarted the scheduled retrieval of this array, until 1975. Glacier visited the new Palmer Station on Anvers Island , after USCGC  Iwsoe , to retrieve USN Seabees and transport them to Punta Arenas for eventual transit back to Davisville, Rhode Island . While departing Arthur Harbor at Palmer Station, Glacier

5085-662: The Pole at a depth of 17 m (56 ft) below the present surface. A flagpole erected at the South Geographical Pole in December 1965 by the First Argentine Overland Polar Expedition has been designated a Historic Site or Monument (HSM 1) following a proposal by Argentina to the Antarctic Treaty Consultative Meeting . In 1820, several expeditions claimed to have been the first to have sighted Antarctica, with

5198-514: The Ross Sea ice pack on 13 November 1961, reaching McMurdo Sound by the end of the month. After repairs at Wellington, Glacier returned to McMurdo Station and to the site of Little America V for cartographic studies. She returned to New Zealand on 6 March 1962 and then put in at Boston on 5 May 1962 after steaming 36,000 nautical miles (67,000 km; 41,000 mi). Glacier stood out of Boston on 17 September 1962 for "Deep Freeze 63", entering

5311-423: The South Pole became more accessible to non-government expeditions. On 30 December 1989, Arved Fuchs and Reinhold Messner were the first to traverse Antarctica via the South Pole without animal or motorized help, using only skis and the help of wind. Two women, Victoria E. Murden and Shirley Metz, reached the pole by land on 17 January 1989. The fastest unsupported journey to the Geographic South Pole from

5424-430: The South Pole by surface transportation, including those by Havola, Crary , and Fiennes . The first group of women to reach the pole were Pam Young, Jean Pearson, Lois Jones , Eileen McSaveney , Kay Lindsay, and Terry Tickhill in 1969. In 1978–79, Michele Eileen Raney became the first woman to winter at the South Pole. Subsequent to the establishment, in 1987, of the logistic support base at Patriot Hills Base Camp ,

5537-476: The South Pole is –49.5 °C (–57.1 °F). The South Pole has an ice cap climate ( Köppen climate classification EF ). It resembles a desert, receiving very little precipitation. Air humidity is near zero. However, high winds can cause the blowing of snowfall, and the accumulation of snow amounts to about 7 cm (2.8 in) per year. The former dome seen in pictures of the Amundsen–Scott station

5650-508: The South Pole on 17 January 1912, thirty-four days after Amundsen. On the return trip, Scott and his four companions all died of starvation and extreme cold. In 1914 Ernest Shackleton's Imperial Trans-Antarctic Expedition set out with the goal of crossing Antarctica via the South Pole, but his ship, the Endurance , was frozen in pack ice and sank 11 months later. The overland journey was never made. US Admiral Richard Evelyn Byrd , with

5763-443: The Sun is roughly perceived to be at its highest). This line of reasoning fails at the South Pole, where the Sun is seen to rise and set only once per year with solar elevation varying only with day of the year, not time of day. There is no a priori reason for placing the South Pole in any particular time zone, but as a matter of practical convenience the Amundsen–Scott South Pole Station keeps New Zealand Time (UTC+12/UTC+13). This

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5876-532: The UK in 2006. She made the journey in 39 days 9 hours 33 minutes. She started on 19 November 2006 and finished on 28 December 2006. In the 2011–12 summer, separate expeditions by Norwegian Aleksander Gamme and Australians James Castrission and Justin Jones jointly claimed the first unsupported trek without dogs or kites from the Antarctic coast to the South Pole and back. The two expeditions started from Hercules Inlet

5989-543: The aim of travelling as far south as possible, and on 31 December 1902, reached 82°16′ S. Shackleton later returned to Antarctica as leader of the British Antarctic Expedition ( Nimrod Expedition ) in a bid to reach the Pole. On 9 January 1909, with three companions, he reached 88°23' S – 112 miles (180 km) from the Pole ;– before being forced to turn back. The first men to reach

6102-507: The approximately 23.5° tilt of the earth's axis. Much of the sunlight that does reach the surface is reflected by the white snow. This lack of warmth from the sun, combined with the high altitude (about 2,800 metres (9,200 ft)), means that the South Pole has one of the coldest climates on Earth (though it is not quite the coldest; that record goes to the region in the vicinity of the Vostok Station , also in Antarctica, which lies at

6215-472: The assistance of his first pilot Bernt Balchen , became the first person to fly over the South Pole on 29 November 1929. It was not until 31 October 1956 that humans once again set foot at the South Pole, when a party led by Admiral George J. Dufek of the US Navy landed there in an R4D-5L Skytrain ( C-47 Skytrain ) aircraft. The US Amundsen–Scott South Pole Station was established by air over 1956–1957 for

6328-466: 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

6441-628: 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

6554-640: 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 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

6667-624: The expanding Arctic and Antarctic oceans. Every year, 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

6780-535: The first being the Russian expedition led by Fabian Gottlieb von Bellingshausen and Mikhail Lazarev . The first landing was probably just over a year later when English-born American captain John Davis , a sealer, set foot on the ice. The basic geography of the Antarctic coastline was not understood until the mid-to-late 19th century. American naval officer Charles Wilkes claimed (correctly) that Antarctica

6893-504: 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 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

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7006-485: The first landing in history on the Princess Martha and Princess Astrid coasts. Glacier returned to Boston , her home port, on 6 May 1956 after these accomplishments. The ship returned to McMurdo Sound on 28 October 1956 for "Deep Freeze II", having made the earliest seasonal penetration in history. Glacier then delivered stores and supplies at McMurdo and then Little America, she led seven other ships of

7119-511: 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

7232-503: 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

7345-449: The geographic pole gradually shift over time. The Geographic South Pole is marked by a stake in the ice alongside a small sign; these are repositioned each year in a ceremony on New Year's Day to compensate for the movement of the ice. The sign records the respective dates that Roald Amundsen and Robert F. Scott reached the Pole, followed by a short quotation from each man, and gives the elevation as "9,301 FT. ". A new marker stake

7458-416: 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

7571-423: 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

7684-534: 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 the ice breaking it. They were used in conjunction with teams of men with axes and saws and

7797-720: The ice was in December 1955, breaking through the Ross Ice Pack , she carved out an ice harbor in Kainan Bay to allow the discharge of cargo from vessels at the site for Little America V . Glacier continued 400 nautical miles (740 km; 460 mi) west to break ice into an off-loading site to establish the U.S. Naval Air Facility at McMurdo Sound . In March 1956, Glacier explored the Weddell Sea . Glacier then surveyed Vincennes Bay in Wilkes Land and made

7910-434: 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 the ice-breaking barge were successful enough to warrant

8023-444: The icy, polar oceans. United States icebreakers serve to defend economic interests and maintain 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

8136-508: 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 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

8249-576: 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

8362-659: 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 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

8475-554: The middle of an ocean. In midsummer, as the sun reaches its maximum elevation of about 23.5 degrees, high temperatures at the South Pole in January average at −25.9 °C (−15 °F). As the six-month "day" wears on and the sun gets lower, temperatures drop as well: they reach −55 °C (−67 °F) around sunset (late March) and sunrise (late September). In midwinter, the average temperature remains steady at around −60 °C (−76 °F). The highest temperature ever recorded at

8588-412: 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,

8701-498: The nearest open sea at the Bay of Whales . The ice is estimated to be about 2,700 m (8,900 ft) thick at the Pole, so the land surface under the ice sheet is actually near sea level. The polar ice sheet is moving at a rate of roughly 10 m (33 ft) per year in a direction between 37° and 40° west of grid north, down towards the Weddell Sea . Therefore, the position of the station and other artificial features relative to

8814-543: The new Canadian polar icebreakers CCGS  Arpatuuq and CCGS  Imnaryuaq , which will have 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

8927-414: The ocean is 24 days and one hour from Hercules Inlet and was set in 2011 by Norwegian adventurer Christian Eide, who beat the previous solo record set in 2009 by American Todd Carmichael of 39 days and seven hours, and the previous group record also set in 2009 of 33 days and 23 hours. The fastest solo, unsupported and unassisted trek to the south pole by a female was performed by Hannah McKeand from

9040-462: The open sea with the use of only one of her two propellers," said the Coast Guard. Two of the three blades on her other screw were sheared off by "steel hard ice" on Wednesday 5 March, while en route to assist an Argentine icebreaker, ARA General San Martín , which had engine trouble while on a supply mission to a south polar scientific base. The Argentine ship made its way to freedom on its own. Following 29 Antarctic and 10 Arctic deployments, Glacier

9153-509: The pack ice on 6 November 1962 and reaching the edge of the bay ice of McMurdo Sound a week later. Glacier sustained minor damage in the thick ice and proceeded to Wellington for repairs. On 31 December 1962, Glacier cut through McMurdo Sound en route to McMurdo Station. She continued operations off McMurdo Station through 1965. Her diverse duties included keeping the channel open for supply ships. On 29 December 1965, US ships Atka and Burton Island assisted her in pushing an iceberg out of

9266-434: The polar regions, facilities and accommodation for the scientific personnel, and cargo capacity for supplying research stations on 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

9379-612: 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 the 9th and 10th centuries, the Viking expansion reached the North Atlantic , and eventually Greenland and Svalbard in

9492-511: 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. South Pole The South Pole , also known as the Geographic South Pole or Terrestrial South Pole , is the southernmost point on Earth and lies antipodally on the opposite side of Earth from the North Pole , at a distance of 20,004 km (12,430 miles) in all directions. It

9605-539: The resupply of North Polar radar and weather stations. By November 1958, however, she was again near the South Pole at McMurdo Sound, and after resupplying the base, steamed to Little America V to begin the station deactivation. Subsequently, while operating in the Terra Nova Bay on the coast of Victoria Land , she discovered two unknown islands and what was likely the largest emperor penguin rookery in

9718-524: The same propulsion power. On 22 August 1994 Louis S. St-Laurent and USCGC  Polar Sea became 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

9831-399: 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

9944-420: 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 the ability of an icebreaker to propel itself onto

10057-506: The shipping lane. After further participation in her 11th "Operation Deep Freeze", Glacier returned to Boston in the late spring of 1966. On 1 July 1966, Glacier was struck from the Navy List , the day after her transfer to the United States Coast Guard . Prior to her transfer to the U.S. Coast Guard, Glacier had her smaller armament removed. In September 1967, Glacier departed her new homeport of Long Beach, California en route to

10170-455: 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

10283-433: The standard for postwar icebreakers until the 1980s. Since the mid-1970s, the most powerful diesel-electric icebreakers have been 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

10396-425: 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

10509-474: 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

10622-422: 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 the ship. Bands of iron were wrapped around the outside. Sometimes metal sheeting

10735-550: 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 the summer navigation season by several weeks. Inspired by the success of Pilot , Mikhail Britnev built

10848-490: 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

10961-596: 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 ) was already well established. The use of

11074-543: The upcoming exploration in the Weddell Sea. Glacier transited the South Pacific Ocean to Punta Arenas, Chile and the Magellan Straits , then entered the Weddell Sea as lead vessel for the 1968 International Weddell Sea Oceanographic Expedition. Glacier occupied most of the scheduled oceanographic sampling stations in the Weddell Sea. Current meter arrays were set with the precise positioning of

11187-429: The vessel from the breakers continued as the ship was taken to the former naval base at Mare Island, Vallejo, on 17 April 2012 for cleaning. Nevertheless, she was towed away to Brownsville, arriving on 19 June. A last-minute stay of execution was rejected, and MARAD ordered her scrapping to begin on 2 July 2012. Icebreaker For a ship to be considered an icebreaker, it requires three traits most normal ships lack:

11300-406: 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

11413-582: The weight of the vessel. The stern was similarly shaped to facilitate breaking ice while backing down. The sides of the icebreaker were rounded, with marked tumblehome , and she had fore, aft and side heeling tanks that enabled the ship to break free from ice by heeling from side to side and changing trim fore to aft. Diesel electric machinery was chosen for its controllability and resistance to damage. Glacier ' s shakedown cruise and maiden voyage were combined in "Operation Deep Freeze I", as flagship for Rear Admiral Richard E. Byrd . Her first encounter with

11526-428: The youngest person to ski to the pole, aged 29. During winter (May through August), the South Pole receives no sunlight at all, and is completely dark apart from moonlight. In summer (November through February), the sun is continuously above the horizon and appears to move in a counter-clockwise circle. However, it is always low in the sky, reaching a maximum of approximately 23.5° around the December solstice because of

11639-548: 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 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

11752-675: Was decommissioned in 1987. She went under the control of the U.S. Maritime Administration , located in the National Defense Reserve Fleet , Suisun Bay , on the Sacramento River , California . The Glacier Society saved Glacier from the scrapyard in 2000, and planned to convert the ship into a hospital or research vessel. However, on 16 February 2012 Glacier was sold for $ 146,726 to be broken up by ESCO Marine in Brownsville, Texas . Efforts to save

11865-537: Was a new continent, basing the claim on his exploration in 1839–40, while James Clark Ross , in his expedition of 1839–1843, hoped that he might be able to sail all the way to the South Pole; He was unsuccessful. British explorer Robert Falcon Scott on the Discovery Expedition of 1901–1904 was the first to attempt to find a route from the Antarctic coastline to the South Pole. Scott, accompanied by Ernest Shackleton and Edward Wilson , set out with

11978-568: Was accomplished, Glacier sailed to Rio de Janeiro , Brazil on 2 April 1960 and provided emergency assistance to flooded areas there for twelve days. Glacier also did relief operations; providing helicopter and boat transportation, and emergency supplies to residents of Paramaribo, Suriname after the floods. Glacier then got underway for Boston , Massachusetts on 17 April 1960. The icebreaker departed Boston on 13 October 1960 on her sixth Antarctic voyage and reached Lyttelton, New Zealand on 21 November 1960 to unload cargo. Most of December 1960

12091-668: 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 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

12204-602: Was one-half mile (0.80 km) astern of USCGC  Southwind . Southwind ran aground on an uncharted pinnacle (now called Southwind Rock), tearing out an 80-by-20-foot (24.4 by 6.1 m) section of hull. Glacier escorted the damaged Southwind across the Drake Passage to Puntas Arena, then up the West coast of South America to the Panama Canal . Glacier then departed Panama Canal for Long Beach. In 1968,

12317-424: 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 is caused by the force of winds and tides on ice formations. The first boats to be used in

12430-542: 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 the bow altered to achieve an ice-clearing capability (20° raise from keel line). This allowed Pilot to push herself on

12543-498: 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 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

12656-661: Was spent in breaking a 21-nautical-mile (39 km; 24 mi) channel through McMurdo Sound to open the way for supply ships. Glacier returned to Wellington , New Zealand for repairs, and to receive the U.S. Navy Unit Commendation for her Bellingshausen Sea expedition success. She then returned to the Amundsen and Bellingshausen Seas on another expedition. Oceanographic work continued until March 1961 when she sailed for Boston, arriving on 27 April 1961. Underway again on 8 October 1961 for "Deep Freeze 62", she loaded cargo at Lyttelton, New Zealand, in early November 1961 and entered

12769-527: 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 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,

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