Poland’s New AIP Submarines Will Transform Navy

The Polish Navy is to acquire submarines from Sweden, massively increasing its capabilities. The two Södermanland Class subs are currently in service with the Swedish Navy. These submarine come with Air Independent Power (AIP, aka Air Independent Propulsion), which will itself be a big leap for the Polish submarine force.

They can submerge for longer and stay hidden in the difficult submarine environment of the Baltic Sea. And they will be upgraded with new capabilities.

Reports of the submarine deal surfaced late last year, and have been confirmed since. It was described at Swedish submarine builder Saab Kockums’ annual submarine seminar on September 3. The government-to-government program will be supported by Saab Kockums who built the submarines.

The Polish Navy currently operates one Soviet-era Kilo Class submarine and two Kobben Class boats. These small German-designed submarines were built in the 1960s, and were in service with Norway before being transferred by Poland. The Swedish subs, even though they are also second-hand, will be a step up for the Polish Navy.

Poland, a NATO member, faces an increasingly potent Russian Navy threat in the Baltic. Russia is upgrading its Baltic Fleet with the latest Pr.677 Lada Class attack submarines. These lack AIP but do have a very large sonar for a non-nuclear submarine. And they are equipped with the Kalibr land-attack cruise missile (LACM).

The unspecified upgrades will bring the Södermanland Class closer to the latest Swedish Gotland and Blekinge Classes. In particular the recent upgrade of the Gotland Class has been referenced. So we can infer that these upgrades could include work to sensors, crew interfaces and combat management systems. Sweden has recently fitted electro-optical masts, to replace the traditional periscopes, to the Gotlands so this is a safe bet. The Gotlands also received the latest AIP, so that is a possibility also.

Sweden is also rolling out a new generation of heavyweight torpedo. This can target both ships and submarines. It is complemented by the brand new Torpedo-47. This lightweight wire-guided weapon is optimized for anti-submarine warfare in the shallow waters of the Baltic. And it has a trick up its sleeve, being able to be loaded two per tube. For many years this seems to have been a secret of the Swedish Navy but is now out in the open.

It is unclear whether the deal will include the new weapons however, and my guess is that it will not. But the existing armament of the Södermanland Class is already formidable. And the upgraded submarines may be capable of carrying the newest weapons if they Poland choses to procure them.

There is no mention of UUVs (Uncrewed Underwater Vehicles), but Swedish submarines are generally ahead in this area. So some organic UUV capability seems possible. The Södermanland Class boats lack the large diameter hangar, known as the multi-mission portal. This will limit the size of UUVs and Sub-ROVs (Remote Operated Vehicles). The latter are swimming robots attached to the submarine by a command wire). But there are torpedo-tube sized UUVs that it could use.

The Södermanland Class submarine deal will surely put Saab Kockums in the lead if Poland acquires new-built submarines. The latest Swedish A-26 Blekinge Class boats would likely face competition from German and French designs. But the design commonality and established defense ties would logically give Sweden an edge. The Södermanland Class are capable, but the A-26 is a step up again.