The Swedish navy’s Gotland-class submarine is simply a reflection of the greatness of Swedish engineering, taking capability in nonnuclear submarines to a new frontier. This class of submarines was developed between 1992 and 1996 and is famous for being the very first class of submarines that integrates an air-independent propulsion system, AIP, which keeps it underwater for a long period, up to two weeks, without surfacing to take oxygen. It is quite a huge improvement from the conventional diesel-electric submarines, which were required to surface within a matter of days.
The Gotland class uses Stirling AIP systems that, in their operation, burn diesel fuel with liquid oxygen to drive two 75-kilowatt electrical generators powering the submarine’s propulsion, giving it the ability to cover 1,700 nautical miles at 5 knots when submerged. This makes the Gotland, despite its modest size, a formidable foe in any kind of naval warfare.
During a 2005 war game, a Gotland-class submarine sneaked up on a $6 billion supercarrier, the USS Ronald Reagan, and “sinking” it along with its entire carrier strike group. In a very convincing manner, the Gotland was able to evade the supercarrier’s passive sonar defenses and score multiple virtual torpedo strikes. The damage that would have been inflicted by the hypothetical attack would have been enough to sink the carrier, and the Gotland slipped away undetected, all without a scratch.
The Gotland class is multi-role, and its capability includes a variety of missions: anti-ship and anti-submarine warfare, communications intelligence, electronic signals intelligence, forward surveillance, special operations, mine-laying, and so on. It is one of the most modern submarines in the Swedish Navy.
The recent hunt for an unknown foreign submersible off of Stockholm reflects the evolving maritime environment in Europe. For six days, the Swedish Navy has engaged in its largest anti-submarine effort since the Cold War, featuring surface combatants, helicopters, ground troops, and probably one or more of Sweden’s AIP attack submarines. While the search was called off without finding the mystery craft, it did net a trove of intelligence information for further analysis.
The operation indicated that there was a need for advanced warfighting capabilities among European navies. In the 1980s, the Royal Swedish Navy conducted several operations against suspected Soviet submarines and built experience in ASW. Nevertheless, the Swedish Navy today is very different from what it was twenty years ago – the number of combatants and submarines is lower.
The recent events in Sweden’s waters suggest that, in an ever more assertive Russia, high-end capabilities will be as relevant in the future as they were during the Cold War. In addition, European naval leaders look upon the rising sea power that is China, so the global maritime environment will likely become more congested and competitive.
The Gotland-class submarine and its cutting-edge AIP, coupled with proven combat capability, underscore Swedish naval power. It is a reminder that even relatively small, modestly priced submarines can present a considerable threat to larger, costlier naval assets.