Project 22220 icebreaker

Project 22220, also known through the Russian type size series designation LK-60Ya, is a series of Russian nuclear-powered icebreakers. , three vessels have been launched at Baltic Shipyard in Saint Petersburg while fourth and fifth have been laid down. Project22220 icebreakers are currently the largest and most powerful icebreakers launched, surpassing their predecessors of the .
Development.
LK-60Ya.
After the Second World War, the Soviet Union launched an ambitious marine transportation development program with the intention of turning the ice-covered Northern Sea Route into a navigable shipping route which could be then used to extract natural resources from the Arctic. This included replacing the obsolete steam-powered icebreakers with more powerful diesel-electric vessels and culminated with the construction of the first nuclear-powered icebreaker in the late 1950s. The second phase, which began in the early 1970s and continued until the dissolution of the Soviet Union, further expanded the Soviet icebreaker fleet with new nuclear- and diesel-powered icebreakers that enabled uninterrupted year-round operation in the western part of the Northern Sea Route as well as extended the navigating season in the eastern sector.
In the 1980s, studies by the Central Marine Research and Design Institute (CNIIMF) and the Central Design Bureau "Iceberg" resulted in "icebreaker type size series" ranging from 7-megawatt auxiliary icebreakers (LK-7) to a 110-megawatt nuclear-powered "icebreaker-leaders" (LK-110Ya). One of the proposed new icebreaker classes, LK-60Ya, was developed as a direct replacement for the previous-generation "Arktika"-class nuclear-powered icebreakers which had entered service in the late 1970s and seen widespread use in the Russian Arctic. In addition to operating as heavy line icebreakers along the full length of the Northern Sea Route from Murmansk all the way to the Bering Strait, the new 60-megawatt icebreakers would also replace the shallow-draft nuclear-powered icebreakers "Taymyr" and "Vaygach" on the Dudinka-Murmansk route which included icebreaking operations in the Yenisey river estuary. The latter operation was made possible by the novel dual-draft functionality, ability to de-ballast the vessel when approaching shallow coastal areas. Other technical characteristics of the next-generation nuclear-powered icebreakers were drawn from the Russians' extensive operational experience from Arctic shipping. For example, it was determined that in order to ensure reliable year-round navigation in the western part of the Northern Sea Route, LK-60Ya would have to be capable of breaking at least ice, an improvement over the old "Arktika"s icebreaking capability. In addition, escorting Russian Arctic cargo ships such as the then-common SA-15 type safely and efficiently in heavy ice conditions would require an icebreaker with a beam of and a displacement of .
While traffic volumes along the Northern Sea Route declined drastically in the early 1990s due to the slowdown of the Russian economy, an ambitious fleet renewal program was nonetheless launched under the presidential program "Revival of the Merchant Fleet of Russia (1993–2000)". In the end, none of the planned icebreakers were built and the follow-up federal program "Modernization of the transport system of Russia (2002–2010)" included funding for the construction of only two new diesel-electric icebreakers in addition to completing the unfinished "Arktika"-class icebreaker "50 Let Pobedy" and starting the preliminary design development of the next generation nuclear-powered icebreakers.
Project 22220.
Although the preliminary design had been developed already in the late 1980s, the final technical design of LK-60Ya was completed in 2009 by Central Design Bureau "Iceberg" as Project22220. 
The construction of the lead ship was awarded to Saint Petersburg-based Baltic Shipyard, part of the state-owned United Shipbuilding Corporation, in August 2012 with a contract price of 36.959 billion rubles (about US$1.16 billion). A 84.4 billion ruble (about US$2.4 billion) follow-up contract for two additional vessels was signed in May 2014 and a second contract, worth over 100 billion rubles (about US$1.5 billion), for two more in August 2019. , there are a total of five Project22220 nuclear-powered icebreakers under construction or on order.
With the Project22220 icebreakers under construction, focus has moved to the development of even larger and more powerful nuclear-powered icebreakers known as Project 10510 Lider.
Construction.
The construction of the first Project22220 icebreaker began with a steel cutting ceremony on 1 November 2012 and the keel of the lead ship of the class was laid on the slipway on 5 November 2013. In a launching ceremony on 16 June 2016, the icebreaker was named "Arktika" () after the first surface ship to reach the North Pole that was in service in 1975–2008. While initially scheduled for delivery by December 2017, the construction of the lead Project22220 icebreaker fell behind schedule due to problems related to the delivery of domestically-sourced components. "Arktika" began the first stage of sea trials in Gulf of Finland under diesel power on 12 December 2019 and returned to Saint Petersburg two days later. The next sea trials, during which the vessel would be tested under nuclear power for the first time, commenced on 23 June and concluded on 13 July. Shortly after completing the final sea trials by mid-September, "Arktika" sailed from Saint Petersburg to Murmansk via the North Pole where the icebreaker arrived on 3 October. The flag-raising ceremony was held in Murmansk on 21 October 2020 and "Arktika" is expected to enter service on the Northern Sea Route in December 2020.
The keel of the second Project22220 icebreaker (referred to as the "first serial ship" of the class in Russia) was laid on 26 May 2015. The icebreaker was launched as "Sibir" () on 22 September 2017. Previously, the name had been used on the second "Arktika"-class icebreaker that was in service in 1977–1992. As with the lead ship, the problems with equipment delivery have postponed the delivery of the vessel from 2018 to 2021.
The keel-laying ceremony of the third ("second serial") Project22220 icebreaker was held on 25 July 2016 shortly after the partially-assembled hull of "Sibir" had been moved down the slipway for final hull assembly. The vessel was launched on 27 May 2019 as "Ural" (). The name had previously been selected for the final "Arktika"-class icebreaker when it was laid down in 1989, but during the construction the vessel was renamed "50 Let Pobedy" (). The delivery of the vessel, initially scheduled for 2020, has been postponed to 2022.
Steel cutting for the fourth ("third serial") Project22220 icebreaker began in late 2019 and the keel was laid on 26 May 2020. The vessel will be named "Yakutiya" ().
The keel-laying ceremony of the fifth ("fourth serial") Project 22220 icebreaker, "Chukotka" (), was held on 16 December 2020.
Design.
General characteristics.
Project 22220 icebreakers are long overall and at design waterline. While the maximum beam is , at design waterline the width of the hull reduces to due to inclined sides. In order to be able to operate efficiently both in shallow Arctic river estuaries as well as along the Northern Sea Route, the draught of the Project 22220 icebreakers can be varied by taking in and discharging ballast water. Originally designed with an operational draught range of , the minimum operational draught has since increased at first to and later to . At minimum draught of , the icebreakers have a displacement of while the full load displacement at design draught is . In terms of size, Project 22220 icebreakers will be longer and wider than "50 Let Pobedy", previously the world's largest icebreaker, and at full load have about one third greater displacement.
The ice class of Project 22220 icebreakers, "Icebreaker9", is the highest assigned by the Russian Maritime Register of Shipping (RMRS) and allows operation in up to thick ice during the winter and spring navigating period.
Power, propulsion and performance.
Like the preceding Russian nuclear-powered icebreakers since the 1959-built "Lenin", Project22220 icebreakers feature a nuclear-turbo-electric powertrain in which nuclear reactors produce steam for turbogenerators which, in turn, generate electrical power for propulsion motors driving the ship's propellers. 
The onboard nuclear power plant consists of two RITM-200 pressurized water reactors with a thermal output of 175 each. The reactors, developed by OKBM Afrikantov, use up to 20% enriched Uranium-235 and, when operating with a capacity factor of 0.65, require refueling every seven years over a 40-year planned service life. The external dimensions of the two-reactor plant located amidships are and each reactor weighs . Two main turbogenerators produced by Kirov-Energomash each generate 36megawatts of electrical power at 3,000rpm.
The propulsion system of Project22220 icebreakers follows the classic polar icebreaker pattern with three shaft lines and a single rudder. The four-bladed fixed pitch propellers, each driven by a electric motor, are made of stainless steel and weigh about apiece. With a total propulsion power of , Project22220 icebreakers supersede the "Yamal" and "50 Let Pobedy" — the two remaining "Arktika"-class icebreakers in service — as the world's most powerful icebreakers.
Project 22220 icebreakers are designed to be capable of breaking thick level ice at a continuous speed of at full power when operating in deep water at design draught. In open water, the icebreakers can achieve a speed of .