Korea's shipbuilding industry keeps surfacing in the same conversations: the Arctic route project centered on the Port of Busan, the Korean-backed American shipbuilding revival known as MASGA (Make American Shipbuilding Great Again), and the development of Alaskan gas fields. Korea holds a favorable position in these projects for an unglamorous reason. Its shipbuilders have spent decades competing against one another to build newer and better vessels, and that competition has compounded into technical capability.
The Arctic route — more precisely the Northern Sea Route, the passage along Russia's northern coast — is no longer a corridor that "might open someday." It is on the table as a live operational option. And whether its central advantage, a shorter voyage that bypasses the Suez Canal, can actually be realized comes down to one question: how reliably, for how much of the year, and how repeatedly can LNG carriers and merchant ships make the round trip through ice-covered waters? Icebreaking LNG carriers have already taken center stage as the way to move gas produced in the Russian Arctic to Asia and Europe, and they are now a critical part of the equation for producing and moving gas from northern Alaska as well.
So any serious discussion of the Arctic route or Alaskan gas has to look at the technology of icebreaking LNG carriers — specifically, at the engineering that keeps a ship from stopping in the ice. This column traces that engineering through the icebreaking and polar applications Samsung Heavy Industries has filed since 2021, and through the design questions shaping the second generation of icebreaking LNG carriers.
[Comparison of the Arctic route (northern) and the existing Suez Canal route (southern)
departing from the Port of Busan]
If the first generation proved a ship could go, the second is a fight to keep it from stopping
The Arc7 ice-class LNG carriers serving Russia's Yamal LNG project were a landmark. Arc7 is an ice-class notation, not a ship class — it describes the ice conditions a hull is certified to work in. Those vessels demonstrated, in the middle of the Arctic Ocean, that breaking ice while carrying LNG is possible. The first generation settled that much.
The question has since shifted. It is no longer whether a ship can make the passage, but how often, over how long a season, and with what fuel and maintenance cost structure — and how far the conditions that bring a ship to a halt can be designed out. The contest over second-generation icebreaking LNG carriers reduces to a single line: not just breaking ice, but keeping the ship moving through every stage of dealing with it.
Sanctions following the war in Ukraine halted Samsung Heavy Industries' business with Russia's Zvezda yard. But the engineering know-how the company accumulated while working on the Arctic LNG 2 project survives intact in its icebreaking and polar applications filed between 2021 and 2024. Followed in sequence, those filings read like an internal worked solution — a record of how the problem of handling ice was broken into functions and then put back toge
[Christophe de Margerie, the world's first icebreaking LNG carrier]
It starts at the bow and the waterline: how to break ice differently
The first thing that stands out is the treatment of the bow and the waterline — the line where the hull meets the water surface.
A 2021 filing, Korean Patent Application No. 10-2021-0125280, proposes an icebreaking bulb projecting forward from the stem. The bulb forces the ice sheet downward and makes it fail in bending — flexural failure, the mechanism icebreakers rely on, because ice is far weaker in bending than in crushing — so the hull that follows meets lower ice resistance. The underlying idea is to isolate the icebreaking function and design it as a discrete module.
Another application filed around the same time, KR 10-2021-0128221, divides the hull itself into two conceptual parts. It carries one form suited to working through drift ice — the broken, free-floating pieces encountered along a route — and another suited to breaking level ice, the unbroken sheet. Which of the two is presented at the surface is changed by transferring ballast water, which alters the vessel's draft and trim. In effect, the ship changes the face it turns toward the ice as conditions change.
Read together, the two filings mark a step beyond the first-generation approach of fixing one bow form and one waterline and living with it for the whole passage. Both are reaching for the same thing: a hull whose effective icebreaking geometry can be varied with ice conditions, operating area, and mode.
[Drawing of a structure inducing bending failure by forcing ice downward with an icebreaking bulb
(Source: KIPO gazette)]
Clearing the broken ice: managing floes and brash ice
Breaking ice is not sufficient on its own. Once broken ice and floes begin crowding back against the hull, the propellers, and the sea chest — the intake through which a large vessel draws seawater to cool its engine room, generators, and pumps — the problem becomes an entirely different one.
The invention titled, in the literal English of the Korean filing, "ice vessel capable of guiding sea ice" (KR 10-2021-0131389) proposes ice deflectors that fold out along the ship's sides, so that broken ice is steered away from the hull and out of the channel — the cleared track of broken ice a vessel leaves behind it — rather than hugging the sides. The insight is that fighting ice along a route is not only about fracturing it, but about keeping the channel clear and wide.
The invention titled "vessel equipped with an ice-fragment inflow prevention device" (KR 10-2021-0141849) moves the point of intervention to the bottom of the hull. A recess, a hinged door, and a deflector wall are built into the bottom shell beneath the bow; during ice navigation the device is deployed downward to intercept broken ice sweeping aft along the bottom, deflect it, and shed it to the sides. The purpose is to keep brash ice — the accumulation of broken fragments in and around the channel — from reaching bottom openings, equipment, and the area around the sea chest.
The experimental thermal and fluid solutions: melt it, or design around it
Other applications from the same period contain more experimental ideas. Among them: a structure that uses fluid jets or heating to clear the ice pockets that form between the podded propulsors — the azimuthing units that both drive and steer this class of vessel; a method of discharging warm fluid from bottom outlet holes to reduce ice accretion on the hull bottom; and a design placing heating coils and a steam supply system in the cofferdams and void spaces, the empty buffer compartments between cargo tanks and the hull, to slow the re-freezing of ice around the hull.
None of these proceeded. Under the Korean Patent Act, examination is not automatic: the applicant — or, distinctively, any third party — must file a request for examination within three years of the filing date, and if no request is filed the application is deemed withdrawn. That is what happened here. The pattern suggests a deliberate choice. Several thermal and fluid-based approaches to the ice problem were explored and then deprioritized, presumably after weighing feasibility, energy efficiency, and cost. The main line of development settled instead on structural design — deciding where ice should be sent and where it must be kept out — rather than on melting it away.
The breathing hole of the cooling system: attention shifts to the sea chest
A 2022 filing titled "vessel capable of operating in Arctic waters" (KR 10-2022-0134542) concentrates on an entirely different layer of the ice problem: the sea chest.
In ice-covered waters, ice pieces, frazil — the fine crystals that form in supercooled water — and slush pack into the chest and block its strainers and piping. Cooling is interrupted, and from that moment the ship stops in the ice regardless of how well it breaks ice.
The application divides the interior of the chest into two spaces, places overlapping fore-and-aft plates perforated with multiple through-holes, and slides the plates relative to one another. In ice conditions the plates are offset to reduce the effective open area and block ice from entering; in open water they are realigned to restore full intake flow. The core idea is a variable sea chest with an ice mode and a normal mode. Where the 2021 filings dealt with ice outside the hull, this one asks a cooling-system question: how far inside should ice-laden seawater be allowed to come?
[Sea chest configured with an ice mode and a normal mode (Source: KIPO gazette)]
The 2024 icebreaking LNG carrier filing: lifting the cooling infrastructure onto the ship platform
The application that consolidates this progression is the 2024 filing, KR 10-2024-0012863, titled in the English of the filing "ICE CRUSHING LNG CARRIER." This time the title and the claims are expressly directed to an icebreaking LNG carrier as such. It is best understood as the work of organizing the earlier concerns — ice sea chest, ballast, air vent, heating module — and applying them within a single vessel-level claim set.
Simplified, the arrangement runs as follows. A side ballast tank and an ice sea chest sit side by side within the ship's side structure. The ice sea chest is the space into which seawater enters to cool the engine, and connected to the top of that space is a vent pipe that releases trapped air to atmosphere and relieves pressure. The intuitive arrangement would run that vent pipe straight up to the deck. This one does not. The vent is routed first through the interior of the side ballast tank — keeping the run inside the hull rather than exposed — and only then upward. A heating module, temperature sensors, and a controller are fitted to the top of the ice sea chest and to that vent run, so that waste heat from the engine or an electric heater manages the temperature of this section automatically.
What the invention is ultimately solving for is this: designing the ice sea chest and vent so that neither freezes nor clogs in ice-filled Arctic waters, keeping the cooling infrastructure breathing. The title says "icebreaking LNG carrier," but the substance is infrastructure design for protecting the cooling system and sea chest in ice conditions — applicable to polar merchant vessels generally, not only to LNG carriers.
side ballast tank / ice sea chest / vent pipe routing (KR 10-2024-0012863)
Icebreaking technology becomes one axis of Arctic route competitiveness
The 2021–2024 arc of Samsung Heavy Industries' icebreaking and polar filings falls into three phases. In 2021, ideas about how to break and handle ice — bow form, waterline, ice management, thermal and fluid approaches — were laid out function by function. In 2022, attention narrowed to the bottleneck in the cooling system, the sea chest, producing a concrete answer to the question of how not to stop: the variable sea chest. And in 2024, all of it was integrated into a single vessel-level claim set, putting the cooling infrastructure of a second-generation icebreaking LNG carrier into one platform.
The competitive question is no longer whether the Arctic route can be used. It is who can reliably build icebreaking LNG carriers that do not stop in the ice — and in what numbers. That is precisely where the discussion of Busan as an Arctic hub connects to Korean shipbuilding, because the yards that can actually design and construct icebreakers and icebreaking LNG carriers sit in Korea, along the southeastern belt linking Busan, Geoje, and Ulsan. Geopolitical risks remain. But being able both to build these ships and to offer the port they sail through is a substantial strategic advantage in Busan's bid for Arctic hub status.
[first-generation icebreaking LNG carrier under way in ice.]
By Taekyun Chung
Patent Attorney, BLT Patent & law Firm
#ArcticRoute #NorthernSeaRoute #Icebreaker #IcebreakingLNGCarrier #IceClass #PolarShipping #SamsungHeavyIndustries #Shipbuilding #MarinePatents #PatentAnalysis #SeaChest #BallastControl #LevelIce #BrashIce #PolarNavigation #Arc7 #YamalLNG #ArcticLNG2 #MASGA #LNGShipping #OffshoreEngineering #EnergyTransport #PortOfBusan #KoreanShipbuilding #IPStrategy #PatentStrategy #KoreanIPFirm #BLT
Korea's shipbuilding industry keeps surfacing in the same conversations: the Arctic route project centered on the Port of Busan, the Korean-backed American shipbuilding revival known as MASGA (Make American Shipbuilding Great Again), and the development of Alaskan gas fields. Korea holds a favorable position in these projects for an unglamorous reason. Its shipbuilders have spent decades competing against one another to build newer and better vessels, and that competition has compounded into technical capability.
The Arctic route — more precisely the Northern Sea Route, the passage along Russia's northern coast — is no longer a corridor that "might open someday." It is on the table as a live operational option. And whether its central advantage, a shorter voyage that bypasses the Suez Canal, can actually be realized comes down to one question: how reliably, for how much of the year, and how repeatedly can LNG carriers and merchant ships make the round trip through ice-covered waters? Icebreaking LNG carriers have already taken center stage as the way to move gas produced in the Russian Arctic to Asia and Europe, and they are now a critical part of the equation for producing and moving gas from northern Alaska as well.
So any serious discussion of the Arctic route or Alaskan gas has to look at the technology of icebreaking LNG carriers — specifically, at the engineering that keeps a ship from stopping in the ice. This column traces that engineering through the icebreaking and polar applications Samsung Heavy Industries has filed since 2021, and through the design questions shaping the second generation of icebreaking LNG carriers.
[Comparison of the Arctic route (northern) and the existing Suez Canal route (southern)
departing from the Port of Busan]
If the first generation proved a ship could go, the second is a fight to keep it from stopping
The Arc7 ice-class LNG carriers serving Russia's Yamal LNG project were a landmark. Arc7 is an ice-class notation, not a ship class — it describes the ice conditions a hull is certified to work in. Those vessels demonstrated, in the middle of the Arctic Ocean, that breaking ice while carrying LNG is possible. The first generation settled that much.
The question has since shifted. It is no longer whether a ship can make the passage, but how often, over how long a season, and with what fuel and maintenance cost structure — and how far the conditions that bring a ship to a halt can be designed out. The contest over second-generation icebreaking LNG carriers reduces to a single line: not just breaking ice, but keeping the ship moving through every stage of dealing with it.
Sanctions following the war in Ukraine halted Samsung Heavy Industries' business with Russia's Zvezda yard. But the engineering know-how the company accumulated while working on the Arctic LNG 2 project survives intact in its icebreaking and polar applications filed between 2021 and 2024. Followed in sequence, those filings read like an internal worked solution — a record of how the problem of handling ice was broken into functions and then put back toge
[Christophe de Margerie, the world's first icebreaking LNG carrier]
It starts at the bow and the waterline: how to break ice differently
The first thing that stands out is the treatment of the bow and the waterline — the line where the hull meets the water surface.
A 2021 filing, Korean Patent Application No. 10-2021-0125280, proposes an icebreaking bulb projecting forward from the stem. The bulb forces the ice sheet downward and makes it fail in bending — flexural failure, the mechanism icebreakers rely on, because ice is far weaker in bending than in crushing — so the hull that follows meets lower ice resistance. The underlying idea is to isolate the icebreaking function and design it as a discrete module.
Another application filed around the same time, KR 10-2021-0128221, divides the hull itself into two conceptual parts. It carries one form suited to working through drift ice — the broken, free-floating pieces encountered along a route — and another suited to breaking level ice, the unbroken sheet. Which of the two is presented at the surface is changed by transferring ballast water, which alters the vessel's draft and trim. In effect, the ship changes the face it turns toward the ice as conditions change.
Read together, the two filings mark a step beyond the first-generation approach of fixing one bow form and one waterline and living with it for the whole passage. Both are reaching for the same thing: a hull whose effective icebreaking geometry can be varied with ice conditions, operating area, and mode.
[Drawing of a structure inducing bending failure by forcing ice downward with an icebreaking bulb
(Source: KIPO gazette)]
Clearing the broken ice: managing floes and brash ice
Breaking ice is not sufficient on its own. Once broken ice and floes begin crowding back against the hull, the propellers, and the sea chest — the intake through which a large vessel draws seawater to cool its engine room, generators, and pumps — the problem becomes an entirely different one.
The invention titled, in the literal English of the Korean filing, "ice vessel capable of guiding sea ice" (KR 10-2021-0131389) proposes ice deflectors that fold out along the ship's sides, so that broken ice is steered away from the hull and out of the channel — the cleared track of broken ice a vessel leaves behind it — rather than hugging the sides. The insight is that fighting ice along a route is not only about fracturing it, but about keeping the channel clear and wide.
The invention titled "vessel equipped with an ice-fragment inflow prevention device" (KR 10-2021-0141849) moves the point of intervention to the bottom of the hull. A recess, a hinged door, and a deflector wall are built into the bottom shell beneath the bow; during ice navigation the device is deployed downward to intercept broken ice sweeping aft along the bottom, deflect it, and shed it to the sides. The purpose is to keep brash ice — the accumulation of broken fragments in and around the channel — from reaching bottom openings, equipment, and the area around the sea chest.
The experimental thermal and fluid solutions: melt it, or design around it
Other applications from the same period contain more experimental ideas. Among them: a structure that uses fluid jets or heating to clear the ice pockets that form between the podded propulsors — the azimuthing units that both drive and steer this class of vessel; a method of discharging warm fluid from bottom outlet holes to reduce ice accretion on the hull bottom; and a design placing heating coils and a steam supply system in the cofferdams and void spaces, the empty buffer compartments between cargo tanks and the hull, to slow the re-freezing of ice around the hull.
None of these proceeded. Under the Korean Patent Act, examination is not automatic: the applicant — or, distinctively, any third party — must file a request for examination within three years of the filing date, and if no request is filed the application is deemed withdrawn. That is what happened here. The pattern suggests a deliberate choice. Several thermal and fluid-based approaches to the ice problem were explored and then deprioritized, presumably after weighing feasibility, energy efficiency, and cost. The main line of development settled instead on structural design — deciding where ice should be sent and where it must be kept out — rather than on melting it away.
The breathing hole of the cooling system: attention shifts to the sea chest
A 2022 filing titled "vessel capable of operating in Arctic waters" (KR 10-2022-0134542) concentrates on an entirely different layer of the ice problem: the sea chest.
In ice-covered waters, ice pieces, frazil — the fine crystals that form in supercooled water — and slush pack into the chest and block its strainers and piping. Cooling is interrupted, and from that moment the ship stops in the ice regardless of how well it breaks ice.
The application divides the interior of the chest into two spaces, places overlapping fore-and-aft plates perforated with multiple through-holes, and slides the plates relative to one another. In ice conditions the plates are offset to reduce the effective open area and block ice from entering; in open water they are realigned to restore full intake flow. The core idea is a variable sea chest with an ice mode and a normal mode. Where the 2021 filings dealt with ice outside the hull, this one asks a cooling-system question: how far inside should ice-laden seawater be allowed to come?
[Sea chest configured with an ice mode and a normal mode (Source: KIPO gazette)]
The 2024 icebreaking LNG carrier filing: lifting the cooling infrastructure onto the ship platform
The application that consolidates this progression is the 2024 filing, KR 10-2024-0012863, titled in the English of the filing "ICE CRUSHING LNG CARRIER." This time the title and the claims are expressly directed to an icebreaking LNG carrier as such. It is best understood as the work of organizing the earlier concerns — ice sea chest, ballast, air vent, heating module — and applying them within a single vessel-level claim set.
Simplified, the arrangement runs as follows. A side ballast tank and an ice sea chest sit side by side within the ship's side structure. The ice sea chest is the space into which seawater enters to cool the engine, and connected to the top of that space is a vent pipe that releases trapped air to atmosphere and relieves pressure. The intuitive arrangement would run that vent pipe straight up to the deck. This one does not. The vent is routed first through the interior of the side ballast tank — keeping the run inside the hull rather than exposed — and only then upward. A heating module, temperature sensors, and a controller are fitted to the top of the ice sea chest and to that vent run, so that waste heat from the engine or an electric heater manages the temperature of this section automatically.
What the invention is ultimately solving for is this: designing the ice sea chest and vent so that neither freezes nor clogs in ice-filled Arctic waters, keeping the cooling infrastructure breathing. The title says "icebreaking LNG carrier," but the substance is infrastructure design for protecting the cooling system and sea chest in ice conditions — applicable to polar merchant vessels generally, not only to LNG carriers.
side ballast tank / ice sea chest / vent pipe routing (KR 10-2024-0012863)
Icebreaking technology becomes one axis of Arctic route competitiveness
The 2021–2024 arc of Samsung Heavy Industries' icebreaking and polar filings falls into three phases. In 2021, ideas about how to break and handle ice — bow form, waterline, ice management, thermal and fluid approaches — were laid out function by function. In 2022, attention narrowed to the bottleneck in the cooling system, the sea chest, producing a concrete answer to the question of how not to stop: the variable sea chest. And in 2024, all of it was integrated into a single vessel-level claim set, putting the cooling infrastructure of a second-generation icebreaking LNG carrier into one platform.
The competitive question is no longer whether the Arctic route can be used. It is who can reliably build icebreaking LNG carriers that do not stop in the ice — and in what numbers. That is precisely where the discussion of Busan as an Arctic hub connects to Korean shipbuilding, because the yards that can actually design and construct icebreakers and icebreaking LNG carriers sit in Korea, along the southeastern belt linking Busan, Geoje, and Ulsan. Geopolitical risks remain. But being able both to build these ships and to offer the port they sail through is a substantial strategic advantage in Busan's bid for Arctic hub status.
[first-generation icebreaking LNG carrier under way in ice.]
By Taekyun Chung
Patent Attorney, BLT Patent & law Firm
#ArcticRoute #NorthernSeaRoute #Icebreaker #IcebreakingLNGCarrier #IceClass #PolarShipping #SamsungHeavyIndustries #Shipbuilding #MarinePatents #PatentAnalysis #SeaChest #BallastControl #LevelIce #BrashIce #PolarNavigation #Arc7 #YamalLNG #ArcticLNG2 #MASGA #LNGShipping #OffshoreEngineering #EnergyTransport #PortOfBusan #KoreanShipbuilding #IPStrategy #PatentStrategy #KoreanIPFirm #BLT