A patrol sub to remain undaunted by the Canadian coastline
Among the contenders to provide Canada with a new fleet of submarines over the next decade, Sweden brings to the competition its extensive naval experience — centuries of defensive and offensive operations on a busy Baltic Sea, with a heightened awareness of just how belligerent the nearby Russian neighbours have become in the last few years.
Over the last three decades, Canada has acquired some of Saab’s products for its own military, such as optronic sensors installed on Halifax-class frigates to control its missile and gun systems. Earlier this year, the federal government announced the $227.5 million purchase of Saab’s RBS 70 short-range air defence system, a portable missile launcher for Canadian troops currently posted in Latvia.
Now, as the Canadian Patrol Submarine Project (CPSP) gathers momentum, Saab would like to provide this country with one of its latest and most sophisticated products — a long-range, expeditionary submarine, bearing the code name C71. The C71 is a modularly expanded version of new Blekinge-class submarines Saab is currently constructing for Sweden’s navy.
Called the A26, two of these smaller vessels are expected to be delivered by 2027 and 2028. With a beam of just under seven metres, an overall length of 66 metres, and a displacement of some 2,000 tons, they will be well suited to service in the Baltic, an inland sea no deeper than 450 metres.
In contrast, the C71 is described as a larger, “expeditionary” Blekinge-class vessel adapted for deep ocean work. In the 1990s, Saab built six Collins-class vessels for the Australian navy on this scale, with a beam of 7.8 metres, a length of 77.8 metres, and a displacement of 3,100 tons. At the time they were the largest conventionally powered submarines ever commissioned, and almost 30 years on, they are likely to remain in service for some time to come, as the Australians begin the long process of outfitting their submarine fleet with nuclear powered replacements.
According to Per-Ola Hedin, Saab’s Chief Engineer for the A26, the C71 is of similarly ambitious proportions, with a beam of roughly eight metres, a length of 80 metres, and a displacement of 3,300 tons. In a recent series of presentations at the company headquarters in Stockholm and the Kockums shipyard in Karlskrona, Saab argued this new vessel could serve Canada’s Atlantic, Pacific, and even Arctic needs, as well as meeting the CPSP’s 2035 delivery deadline.
Saab representatives underscored this prospect by referring to the company’s track record, which this year marks 110 years of building more than a dozen different types of undersea vessels, from traditional crewed boats to remotely operated and autonomous vehicles. More specifically, the Swedes tout their expertise with an innovative engine design enabling diesel-electric propulsion to increase submerged endurance from days to weeks, offering a significant degree of the performance typically associated with nuclear submarines.
Known as Air Independent Propulsion (AIP), it employs the Stirling engine, a closed-cycle heat engine invented some 200 years ago, which requires no external atmosphere to operate.
As Hedin explained, AIP makes for a quieter submarine, since it does not require the constant pumping of coolant through a reactor. This virtue was driven home during a set of international war games in 2005, when one of Saab’s Gotland-class submarines famously “sank” the newly commissioned US carrier Ronald Reagan by snapping a photograph of the carrier without ever being detected. The accomplishment impressed the US Navy sufficiently to inspire a Memorandum of Understanding with Sweden to lease one of its submarines and its crew, which spent the next two years in California participating in exercises to help the American forces determine how to deal with the potential threat from less friendly nations that might be developing their own AIP underwater fleets.
While continuously developing the Stirling AIP technology, Saab, together with Swedish research institutes, are investing in new battery technology to improve operational performance even further.
Rear Admiral Jens Nykvist, now Sweden’s Deputy Chief of Defence Staff, was among the submariners who took part in the work at San Diego’s Naval Base Point Loma from 2005 to 2007. At that time, he recalls, his country was beginning a reduction in its international military profile and maritime industrial capacity, highlighted by the sale of the venerable Kockums shipyard in southern Sweden to German shipbuilding conglomerate Thyssen Krupp. Kockums’ only customer was the Swedish military, which wanted to use the facility for its highly classified development of the A26, despite the German firm’s reluctance to participate. The project floundered until Russia’s 2014 invasion of Crimea, when a shaken Swedish government adopted a fresh policy of strong domestic industrial defence capability, which was to make the building — and exporting — of the A26 an entirely Swedish initiative. After a tense confrontation with Thyssen Krupp, Saab ultimately acquired Kockums, where the two new submarines are now being assembled.
For Nykvist, the shock of Russia’s Crimean adventure was redoubled when the country moved on Ukraine in 2022. He credited this continuing conflict for swelling popular support to make Sweden the 32nd member of the NATO alliance earlier this year. While this new status may not put the country on a war footing, it has further sharpened the call for situational awareness along the country’s 2,100-kilometre coastline, which features hundreds of thousands of islands. The stealth of submarines is essential to observe objectively, he argued, without influencing activities that may be taking place on the surface, or below.
“What is important is presence,” said Nykvist, “to be able to have the presence to see what’s ongoing and see what is not a normal picture.”
That same credo could be applied to Canada’s need for situational awareness, especially in a rapidly evolving Arctic. With a daunting three-ocean coastline totalling more than 240,000 kilometres, and a warming climate opening up some of the most remote sections to international shipping traffic, the “normal picture” promises to be a moving target for decades to come. While nuclear powered vessels have established their ability to move freely and fully around this kind of extensive, complex environment, newer technology is pointing the way to more cost-effective options Canada could be bring into service more quickly.
Saab presents the C71 as a lynchpin for bringing together those options, starting with AIP. While this technology is to allow the A26 to remain continuously submerged for up to 21 days, Hedin suggested the C71 could more than double that time. He noted the range could also be extended to 24,000 kilometres, a distance more aligned with the scale of Canadian missions.
While those figures might be derived from design specifications of Blekinge-class vessels that have yet to hit the water, there are more definitive advantages to be considered. The required crew complement of the A26 will be less than 30, and just a few more for the C71. That would be just over half of what it takes to run one of Canada’s Victoria-class submarines, introducing a significant reduction in the volume of supplies required for these people, not to mention a likely improvement in their on-board quality of life.
As for the demonstrated performance of AIP on longer ocean voyages, Kockums Stirling engines were a defining feature of Japan’s large Soryu-class submarines, which were introduced in 2009. With a beam of more than nine metres, a length of 84 metres, and displacement of more than 4,000 tons, a Canadian Forces College paper by Lieutenant Commander Iain Meredith cites claims these vessels can remain submerged for at least 40 days and have a range of more than 11,000 kilometres while being powered by AIP.
Saab regularly maintains and upgrades its existing submarines by cutting the hull into sections, then reattaching them later. The A26’s construction started with this approach, and the larger dimensions of the C71 are simply based on expanding the size and number of these sections. This modularity means any special features Canada might want to include in its version of the C71 can be incorporated into these sections before any assembly begins, as could any additional features years later during scheduled maintenance.
In this regard, perhaps the most intriguing aspect of the A26 and the C71 is its adaptability for armaments and specialized equipment. While these submarines can be outfitted with a full array of torpedoes, surface-to-air, and surface-to-surface missiles, some of the forward launch tubes can be replaced with a much larger opening Saab calls a multi-mission portal. Accessed from inside like an air-lock, this portal would be sizeable enough to accommodate a dive team or an autonomous vehicle, which could then exit and re-enter the submarine while it is submerged.
Such a portal is integral to participating in what Hedin described as seabed warfare, consisting of operations conducted on or near the ocean floor. In addition to keeping an eye on infrastructure such as pipelines or communications lines, submarines could also take advantage of dedicated equipment put in place for military purposes. When asked about such systems, Swedish military officials were coy, but Saab representatives and others have been candid about the prospects of installing seabed systems in the Canadian Arctic, servicing long range, uncrewed underwater vehicles (UUVs) to patrol beneath the ice.
Saab Canada President Simon Carroll pointed to the pace of this technology’s progress, challenging the necessity of risking crewed vessels under Arctic ice when the same level of reconnaissance will ultimately be possible with UUVs. Should Canada take this approach to maintaining its presence in this region, the C71 multi-mission portal would then become a crucial element in servicing a distinct fleet of these smaller craft, adding an entirely new dimension to the country’s undersea naval operations.
Here, too, Saab is already developing such craft, along with the software to guide them accurately and securely. Known as Autonomous Ocean Core, this open-system programming is to be adapted to almost any kind of independently operating surface or underwater vehicle, providing a common platform for operators to integrate navigation, sensors, weapons, and other functions they might want to assign to a UUV operating along the Arctic coastline.
As for where this new fleet of Canadian submarines might be built, Saab President and CEO Micael Johansson referred to lessons learned from its experience of trying to sell his company’s fighter jets to this country. In particular, he pointed to the need for Saab’s products to be interoperable with Canada’s, something that Sweden’s newly acquired NATO membership will ensure.