An icebreaker is a special-purpose boat or ship made to move through ice-covered seas and open up navigable channels for other vessels. Although the phrase typically refers to ships that break the ice, Icebreakers may also be used to describe smaller boats, such as the icebreaking boats that were historically used on the canals in the United Kingdom. Icebreakers break through frozen water or pack ice to open up pathways.
The bow of an icebreaker can be driven onto the ice in extremely thick ice that would crack under the ship’s weight. Sea ice often breaks without considerably changing the ship’s trim since it has such a low bending strength. Icebreakers have a specifically crafted hull to steer the fractured ice beneath or surrounding the boat, as an accumulation of broken ice in front of a boat can slow it down much more than actual ice breaking.
Below is a list of the largest Ice Breakers in the world.
Taymyr is a shallow-draft nuclear-powered icebreaker. She was constructed in 1989 by Wärtsilä Marine on behalf of the Murmansk Shipping Company in Helsinki, Finland, for the Soviet Union.
|Launch Date||April 10, 1987|
KLT-40M nuclear fission reactor with a 171 MW thermal output powers Taymyr. The nuclear power plant on board the icebreaker generates superheated steam, which produces heat to maintain operational capability at 50 °C (58 °F) and electricity for the propulsion motors and other shipboard customers.
13. USCGC Polar Star (WAGB-10)
USCGC Polar Star (WAGB-10) is a heavy icebreaker for the US Coast Guard. The ship was put into service in 1976 and was constructed by the Seattle, Washington-based Lockheed Shipbuilding and Construction Company with her sister ship, the USCGC Polar Sea.
The United States Coast Guard’s Ice Operations Section manages Polar Star’s Seattle-based operations, which the Coast Guard Pacific Area coordinates.
Polar Star was the sole heavy icebreaker operating in the US after Polar Sea was decommissioned in 2010. Despite being categorized as a “medium icebreaker,” the only other icebreaker in the Coast Guard’s fleet, USCGC Healy, is more significant than “Polar Star” (13,623 LT versus 16,000 LT).
A gas turbine or diesel-electric prime mover turns the ship’s three shafts. A 16-foot (4.9 m) diameter, four-bladed propeller with variable pitch is attached to each shaft. The gas turbine plant can generate 75,000 shaft horsepower, and the diesel-electric plant has 18,000 shaft horsepower (13 MW).
|Name||USCGC Polar Star|
|Launch||November 17, 1973|
|Speed||18 knots (3 knots in 6-foot ice)|
|Displacement||10,863 long tons|
The fourth icebreaker used by Japan for trips to Antarctica is called Shirase and is managed by the Japan Maritime Self-Defense Force. Her predecessor left her with a name. With the hull number AGB-5003, she was launched in April 2008 and put into service in May 2009. She set out on her first journey on November 10, 2009.
|Launch||April 16, 2008|
|Speed||19.5 knots (3 knots in ice)|
|Displacement||Approximately 20,000 TONS|
The nuclear-powered icebreaker Vaygach has a shallow draft. She was constructed in 1989 for the Soviet Union by the Finnish shipyard Wärtsilä Marine Helsinki under contract with the Murmansk Shipping Company. Taymyr is her sister ship. One KLT-40M nuclear fission reactor with a 171 MW thermal output, placed amidships, powers Vaygach.
|Launch||February 26, 1998|
The nuclear power plant on the icebreaker produces superheated steam, which is used to create heat to keep operational capability at -50 degrees, and electricity for the propulsion motors and other shipboard customers.
Each of Vaygach’s two primary turbogenerators, made up of Soviet-built steam turbines connected to Siemens generators and providing 18,400 kW of energy at 3,000 rpm for the propulsion motors, is located aft of the reactor compartment.
While the icebreaker was escorting commercial ships from Dudinka to Murmansk on December 15, 2011, a fire on board Vaygach claimed that two crew members were lost, while a third was seriously hurt.
Sibir is a Russian nuclear-powered icebreaker from Project 22220. Sibir was laid down in 2015, launched in 2017, and delivered in December 2021 by Baltic Shipyard in Saint Petersburg. Sibir uses a nuclear-turboelectric propulsion system.
Two 175 MWt RITM-200 pressurized water reactors powered by up to 20% enriched Uranium-235, and two 36 MWe turbogenerators make up the onboard nuclear power plant.
The propulsion system uses three 6.2-meter (20-foot) four-bladed propellers powered by 20-megawatt (27,000 hp) electric motors, the standard design for polar icebreakers. When operating in deep water at design draught, Sibir is expected to break through 2.8 meters (9 ft) of level ice at a constant speed of 1.5-2 knots (2.8-3.7 km/h; 1.7-2.3 mph). It has a total propulsion capacity of 60 megawatts (80,000 horsepower).
|Launch||September 22, 2017|
|Speed||22 knots (2 knots in ice)|
The RV Polarstern, which translates to “polar star,” is a research icebreaker operated by the Bremerhaven, Germany-based Alfred Wegener Institute for Polar and Marine Research (AWI). Polarstern, constructed by Howaldtswerke-Deutsche Werft in Kiel and Nobiskrug in Rendsburg and launched in 1982, is mainly used for polar research.
The icebreaker’s length is 118 meters (387 feet), and it has two hulls. She can function in a room as cold as 50 °C (58 °F). Polarstern can move at a pace of 5 knots (9.3 km/h; 5.8 mph) over ice 1.5 meters (4 feet 11 inches) thick. Ramming can break thicker ice up to 3 m (9.8 ft) thick.
|Launch||February 6, 1982|
For BeauDril, the drilling division of Gulf Canada Resources, she was constructed in 1983 as an icebreaking anchor handling tug supply vessel (AHTS) Ikaluk to aid in offshore oil exploration in the Beaufort Sea. The ship was bought by Canadian Marine Drilling (Canmar) in the 1990s, and its new name is Canmar Ikaluk.
Smit International bought her in 1998, and as Smit Sibu, she worked in the Sakhalin oil fields. She was purchased by FEMCO Management in 2009 and received her old name back in 2012. In February 2018, Ikaluk was sold to China and renamed Beijing Ocean Leader.
The yacht was sold to its present owner in late 2021. The vessel is intended to shatter 1.2 meters (3.9 ft) level of ice at a speed of 3 to 4 knots (5 to 7 km/h; 3.5 to 4.6 mph) when operating at maximum power.
An additional tool for icebreaking is the OmniThruster unit’s active hull lubrication system, which uses nozzles along the forward half of the ship to discharge an air/water combination between the hull and the ice to keep the ship from getting trapped.
The icebreaker can cruise at 12.5 knots (23.2 km/h; 14.4 mph) with two engines while in the open sea at a speed of 15.5 knots (28.7 km/h; 17.8 mph) with four engines running.
|Launch||November 15, 1982|
|Speed||15.5 knots (3 knots in ice)|
The largest and most sophisticated icebreaker in the United States and the largest ship in the US Coast Guard’s fleet is the SCGC Healy (WAGB-20). The Coast Guard has assigned her the designation of a medium icebreaker. She was commissioned in 1999 and had Seattle, Washington, as her homeport.
Healy offers up to 50 scientists’ lodging, more than 4,200 square feet (390 m2) of scientific laboratory space, a wide array of electronic sensor systems, and oceanographic winches. Healy can function in low temperatures and is designed to break ice up to 10 ft (3.0 m) thick when backing and ramming. It can also continuously break ice up to 4.5 ft (1.4 m) thick at 3 knots (5.6 km/h; 3.5 mph).
|Launch||November 15, 1997|
6. CCGS Louis S.St-Laurent
CCGS Louis S. St-Laurent Louis S. St-Laurent is a heavy icebreaker for the Canadian Coast Guard (CCG). It is the CCG’s flagship and largest icebreaker. Canadian Vickers Limited launched the Louis S. St. Laurent on December 3, 1966, in Montreal, Quebec, and it was put into service in October 1969.
|Name||Louis S. St-Laurent|
|Launch||June 3, 1966|
5. USCGC Mackinaw
The 240-foot (73 m) multipurpose vessel USCGC Mackinaw (WLBB-30) was constructed for the United States Coast Guard’s activities on the North American Great Lakes with a heavy icebreaker as its primary role.
Two Azipod units, an ABB brand of electric azimuth thrusters, are used as the main propulsion of the Mackinaw, making it distinct from other vessels in the US Coast Guard fleet. Thanks to them and a 550 hp (410 kW) bow thruster, the ship is incredibly maneuverable.
As the thrusters can be turned 360 degrees around their vertical axis to direct their force in any direction, the Azipod units also do away with the requirement for a conventional rudder. The Mackinaw doesn’t have a typical ship’s wheel either. The Finnish Maritime Cluster supplied a large portion of the ship’s technology, including the Azipod thrusters.
Additionally, at 3 or 10 knots, the Mackinaw can travel unhindered through freshwater ice up to 32 inches (81 cm) thick. She can also shatter 42 inches (107 cm) of continuous, smooth ice by standing on top of it and stomping down on it with the weight of her bow.
|Launch||April 2, 2005|
|Propulsion||Integrated main propulsion and electrical plant|
4. 50 Let Pobedy.
On October 4, 1989, work on Project No. 10521 at the Baltic Works in Leningrad, then known as Saint Petersburg, USSR, began. The ship’s original name was Ural. Due to a lack of funding, construction was put on hold in 1994, and when Victory Day’s 50th anniversary rolled around in 1995, the ship was in an abandoned state. In 2003, construction resumed back up.
|Name||50 Let Pobedy|
|Launch||December 29, 1993|
3. S.A. Agulhas 2
The Department of Environmental Affairs owns the South African icebreaking polar supply and research ship S. A. Agulhas II (DEA). To replace the outdated S. A. Agulhas, removed from Antarctic service in April 2012, she was constructed in 2012 by STX Finland Rauma shipyard in Rauma, Finland.
The ship includes a diesel-electric propulsion system with two 4,500 kW Converteam propulsion motors that propel 4.5-meter (15-foot) KaMeWa controllable pitch propellers, which is a somewhat unique feature in diesel-electric ships that typically utilize fixed-pitch propellers.
Her operating range is 15,000 nautical miles at 14 knots (26 km/h; 16 mph), which is slightly slower than the propulsion system’s maximum speed of 16 knots (30 km/h; 18 mph) in open water (28,000 km; 17,000 mi).
Additionally, S. A. Agulhas II is built to shatter level ice at a speed of 5 knots (9.3 km/h; 5.8 mph) with a thickness of 1 meter (3.3 ft). She features two Rolls-Royce bow thrusters and one Rolls-Royce stern thruster for dynamic positioning and port maneuvering.
|Name||S.A. Agulhas II|
|Launch||July 21, 2011|
Yamal is a Russian nuclear-powered icebreaker of the Arktika class that Atomflot runs. The twin hull of Yamal is present. The exterior hull has a polymer covering to decrease friction and is 48 mm (1.89 in) thick when ice is encountered and 25 mm (0.98 in) thick elsewhere.
Water ballast can be moved between the inner and outer hulls to help in icebreaking. An air bubbling system delivering 24 m3/s (850 cu ft/s) of air from jets 9 m (30 ft) below the surface also helps with icebreaking.
A crew member perished on December 23, 1996, when a fire started on the icebreaker. The fire did not impact the nuclear reactor that powered the ship. Within 30 minutes, the crew put out the fire. In the Yenisei Gulf of the Kara Sea on March 16, 2009, the Yamal collided with the product tanker MT Indiga.
No damage was noted for Yamal. However, the tanker’s main deck sustained a 9.5-meter (31-foot) break. Amal can move either forward or backward while breaking through ice.
In the Baltic Shipyard in what was then Leningrad, work started on a conceptual design for a larger nuclear icebreaker on July 3, 1971. Moscow and Leningrad learned by radio on December 17, 1975, four years after the sea experiments began, that they had been successful. At the time, the Arctic was prepared for the newest and largest nuclear icebreaker.
The propellers’ combined output of 18–43 MW (25,000 shaft horsepower) [total: 55.3 MW (75,000 hp)] can lift 480 tons of bollards. On open water, this translates to a top speed of 22 knots (41 km/h; 25 mph), a full speed of 19 knots (35 km/h; 22 mph), and an average speed of 3 knots (5.6 km/h; 3.5 mph) while icebreaking ice that is 2-3 meters (7-10 ft) thick on the level.