The Arctic is warming roughly four times faster than the global average, making shipping lanes that were theoretical a decade ago commercially viable sooner than even optimistic projections suggested.

 

Geopolitics is also driving increased interest in these waters. The Northern Sea Route not only offers transit times some 30 to 40% shorter between the Far East and Europe than traditional Red Sea routes, it also avoids conflict zones, piracy hotspots and strategic bottlenecks. In a volatile world, nations are taking their Arctic territories more seriously, particularly given their resource potential. The Arctic holds vast reserves of oil, gas and critical minerals, but the vessels and infrastructure to support extraction don’t yet exist at the required scale.

 

“The Arctic in particular feels like it’s moved almost overnight from a specialist niche to one of the most contested and commercially significant maritime regions on the planet,” says Lee Grace, business development manager, North America, at maritime engineering consultancy BMT. 

A Canadian Coast Guard icebreaker with its distinctive red-and-white livery (image: Getty images/Canadian Coast Guard)

 

The range of vessels on the order books tells a story. On the commercial side, bulk carriers and containerships are exploring trans-Arctic routes as summer ice-free windows arrive earlier than predicted. Research ships are in demand as governments fund deeper understanding of these environments. And icebreakers, the heavy-duty workhorses that make everything else possible, are suddenly high on procurement agendas.

 

“Most western nations look at their fleets and see a significant capability gap,” says Grace. “Arctic patrol vessels for coastguard and sovereignty missions are another major driver, and increasingly we’re seeing something genuinely new: serious interest in purpose-designed autonomous vessels for persistent polar monitoring.”

 

Arto Uuskallio, head of sales and marketing at Railotech, the Finnish icebreaking specialist, says that although there are currently four different Polar Class 2 vessels under construction, most customers are looking for vessels with carefully tailored ice capability. By this he means designs that combine “adequate ice performance with good open-water efficiency and seakeeping properties, rather than designs optimised only for extreme year-round Arctic conditions”.

 

He says: “A record number of diverse ice-capable vessel projects are under development, with several more in the pipeline,” adding that the strongest demand is in government and coastguard ships, and research, cargo and logistics vessels.

 

New ice risks

Ice-class ships aren’t new, but the design challenges are becoming more complex. “The environment is changing faster than the design codes that govern how we build for it,” says Grace.

Carving a transit channel through Arctic pack ice (image: Getty images/Canadian Coast Guard)

 

Traditionally, ice-class design meant designing for a relatively predictable adversary: thick pack ice. The answer was largely about strength: heavier frames, reinforced plating at the waterline and bow forms built to break through. But climate change has made that adversary far less consistent.

 

“The older, thicker multi-year ice is reducing, but what’s replacing it isn’t simply open water – it’s a more dynamic mix of younger first-year ice, refreezing floes, shifting leads and unpredictable ice edges,” Grace says. “Paradoxically, a partially ice-covered Arctic can be more dangerous than a heavily iced one, because the behaviour is so much less predictable.”

 

Designers also need to take a long view. The Arctic in 2050 could look very different from today. This is where digital twin technology comes into its own, to test hull form and propulsion choices against future climate scenarios before committing to a physical design.

 

Understanding the ice type matters, with the spectrum running from thin, newly formed nilas ice through first-year ice, typically up to 1.5m thick after one winter’s growth, to old, multi-year ice that has survived at least one summer melt.

 

“Designing a vessel for breaking 50cm ice is fundamentally different from designing for 250cm level ice,” says Uuskallio. “These differences affect hull strength, propulsion power, material selection, equipment makers, machinery design, winterisation and even basic layout choices.”

 

There is also an important structural trade-off: the more ice-capable a vessel needs to be, the heavier its structure must become – reducing the internal volume available for cargo, mission systems and crew spaces.

 

Ice conditions are highly variable. A vessel may encounter level ice, ridges, brash ice and pressure zones within the same voyage, each imposing different loads on the hull, propulsion and steering systems. “This variability makes it essential to clearly define the ice conditions and operational assumptions at the very beginning of the design process,” says Uuskallio.

 

A hull optimised for breaking solid pack ice performs very differently from one optimised for open-water efficiency and seakeeping. Shorter ice seasons mean vessels now spend more time in open water and getting that balance right across a much wider range of conditions is the central design challenge.

 

Increased ice strength and power improve safety and reliability in ice, but they also add weight, resistance, fuel consumption and emissions in open-water operation. Achieving a well-balanced design that meets the most demanding requirements without overdesigning for less critical ones is the core challenge.

 

In Atlantic Canada, this hull-form tension is particularly acute on the east coast, where ships frequently transit to the high Arctic through summer and autumn, then return to the North Atlantic, one of the harshest open-ocean wave environments in the world.

“A hull optimised for icebreaking tends to roll heavily in open seas,” says Grace. “Conventional stabilisers and bilge keels can’t be fitted due to ice damage risk.”

 

Double-acting ships, as pioneered by Railotech, designed to break ice astern, freeing the bow for a more conventional form and better seakeeping, haven’t yet been tried in Canada. It’s a concept that “deserves serious consideration”, notes Grace. 

 

Forging innovation

The challenges of ice-infested waters are fertile ground for innovative design features. These include the ice knife – a structural bow feature that splits and directs broken ice under the vessel. It features in Canada’s new heavy icebreaker under construction at Seaspan. Heeling tanks allow a vessel to rock itself free when trapped in ice while air bubble systems thrust compressed air through ports at the bow to reduce friction, complementing bow lubrication systems. And oblique icebreaking – achieved through an asymmetrical hull form – allows a vessel to open a channel wider than its own beam, useful for following traffic.

 

“Advanced hull forms and propulsion concepts, such as double-acting operation, allow ships to achieve good open-water efficiency and to handle demanding ice conditions when required,” says Uuskallio. “Improved numerical methods, particularly nonlinear finite element analysis, combined with extensive full-scale measurement data are enabling more accurate assessment of ice loads. This makes it possible to optimise structures so they are lighter and safer, without simply increasing ice class as a conservative solution.”

 

Real-time data is key. Fed into digital twin models it can create a continuous picture of hull condition and predict maintenance needs before they become failures. “When the nearest drydock is thousands of miles away, that capability is operationally essential,” says Grace, who also highlights the importance of increased satellite coverage and communications equipment in these remote waters.

Vessels may encounter level ice, ridges, brash ice and pressure zones on the same trip (image: Getty images/Canadian Coast Guard)

 

Bear necessities

If something goes wrong in the polar regions, the search and rescue response time is measured in days, not hours. Designers need to ensure there are fully enclosed, thermally insulated lifeboats that can sustain survivors for extended periods in extreme cold, and medical facilities that can manage serious trauma without rapid evacuation.

 

And while not usually the subject of naval architecture, “the vessel’s freeboard needs to be high enough to prevent polar bears from boarding,” says Grace. 

 

 

Research vessel

 

Onboard one of the world’s most advanced polar research ships.

RRS Sir David Attenborough, operated by the British Antarctic Survey, began service in 2021 and feedback from the scientists onboard has been very positive, says Kongsberg Maritime designer Erik Leenders.

 

He points out polar research vessels pose specific challenges for naval architects, as these ships combine multiple functions. Sir David Attenborough, for example, is a cargo ship loaded with 20ft containers, a product tanker carrying diesel and aviation fuel, a ‘passenger’ ship for 60 scientists and a research ship with bespoke laboratories, moonpool and ROVs – not to mention being a Polar Ice Class 5 (Hull PC4) icebreaker, which can operate year-round in medium, first-year ice, breaking through ice 1m thick at a speed of 3knots (5.6km/h).

RSS Sir David Attenborough

 

The £200 million ship is deployed to the Arctic during the northern summer and to the Antarctic during the austral summer. “It travels from the northern hemisphere to the tropics to 40, 50, 60°,” explains Leenders. “Icebreaker hulls do not tend to be very good seakeeping hulls so we did a lot of tests in the ice tank and seakeeping tank to check the hull design. We’ve had very good feedback from the crew about its handling and, of course, it is rated to a very high comfort class (LR: CAC1), with a lot of focus on space, noise and vibration, because the crews spend a really long time onboard.”

 

The ship has a helipad and hangar for two helicopters, cranes and an enhanced ability to deploy subs and other ocean-survey and sampling equipment.

 

This article appeared in Designing for Extremes, TNA May/June 2026.