July 1, 2022

Submarine Aspects of Sweden & Finland Joining NATO

Poor Putin is nonplussed that his bold plan to invade Ukraine (in 3? days) thus  demoralizing and disuniting NATO has failed

Instead there is a resurgent, focussed, NATO, with 2 hitherto "neutral" countries, Sweden and Finland, about to join that alliance. Several non-NATO countries like Australia have grown closer to NATO in supporting Ukraine and outing Russia.

Turkey's opposition to Sweden and Finland joining NATO was based on those 2 countries harbouring Kurds that Turkey considers terrorists.  

Now that Sweden and Finland have promised laws that will "crackdown" on Kurdish militants Turkey has lifted its opposition. It is also possible that Sweden and Finland, under NATO intelligence sharing agreements, will also regularly pass on intelligence to Turkey regarding militant Kurdish activities.

When Sweden joins NATO this will end 200 years of non-alignment. 

When Finland joins NATO this will reject Soviet/Russian/Putin hardline-esque pressure for 77 years (since WWII) that has kept Finland "Finlandized" ie. forcibly neutral. 

With Finland NATO's northern border with Russia will expand greatly (see map below). Putin was/is specifically opposed to NATO bordering Russia's heartland, hence his Ukraine fiasco. The Baltic will become a proverbial NATO surrounded "lake" making Russian Baltic Fleet activities more difficult.  

Submarine wise:

Sweden's well established submarine corps will be a significant formal asset for NATO. Informally those subs have helped NATO for years. Sweden's Gotland-class subs should last until about 2030? Sweden's 2 Sodermanland-class subs are due to be replaced by 2 x A26 Blekinge-class in 2027-28. Two (and maybe 3?) additional Blekinges are planned to replace the Gotlands around 2030. 

Strategic Gotland island itself (in the Baltic) is believed to be at risk from the Russians.

-  For Finland I don't know whether its long and severe Winter months ice-in its navy? See the Soviet-Finnish 1939-40 Winter War. Might this marginalize any Finnish submarine corps option? 

European countries that joined NATO before and after 1997. (Map courtesy BBC June 29, 2022.)

As well as Sweden and Finland, as of June 2022, 3 additional states have formally informed NATO of their membership aspirations, they are: Bosnia and HerzegovinaGeorgiaand Ukraine.[1] Joining the alliance is a debate topic in several other European countries outside the alliance, including IrelandMoldova, and Serbia. 


Anonymous said...

Thanks Pete

The Baltic ices up north of Turku and Stockholm every winter. Sweden and Finland have excellent icebreakers so these ports remain busy year round along with Helsinki. So Swedish subs rarely if ever get iced in. The northern Baltic is shallow and not great sub country anyway.

Finland has had no subs since WWII following conditions of its peace treaty with the Soviet Union. Its navy only has patrol boats and minesweepers up to Corvette size. ASW and minesweeping are the main priorities. That may all change as part of NATO; Finland historically was the first country to operate German designed subs in the 1930s that were forerunners of German Type VIIs.

Obviously, with Finland, Sweden, Poland, Germany and Denmark all now in NATO, the potential for a Baltic version of SOSUS to bottle up Russian Baltic fleet subs is now very high.

My grandfather was Finnish and came from the port of Rauma north of Turku.

Pete said...

Hi Anonymous

Thanks so much for the Finnish submarine and icebreaking information - knowledge handed down by your grandfather and all.

With Finland joining NATO it may opt for 2 or 3 small (less than 1,000 tonne) submarines. The 500 tonne future Turkish built STM 500 might be useful. I've added Finland to the possible buyer list here https://gentleseas.blogspot.com/2022/06/turkeys-stm-500-sub-tkms-type-205-210.html.

Thanks for "Finland historically was the first country to operate German designed subs in the 1930s that were forerunners of German Type VIIs"

I have identified Finnish submarine Vesikko https://en.wikipedia.org/wiki/Finnish_submarine_Vesikko

"which was launched on 10 May 1933 at the Crichton-Vulcan dock in Turku. Until 1936 it was named by its manufacturing codename CV 707. Vesikko was ordered by a Dutch engineering company Ingenieurskantoor voor Scheepsbouw (a German front company) in 1930 as a commercial submarine prototype, being the prototype for the German Type II submarines.

Purchased by the Finnish before World War II, she saw service in the Winter War and Continuation War, sinking the Soviet merchant ship Vyborg as her only victory. After the cease-fire with the Allies in 1944, Vesikko was retired...Vesikko was one of five submarines to serve in the Finnish Navy. The other four were the three larger Vetehinen-class boats Vetehinen, Vesihiisi, Iku-Turso and the small Saukko. The word "vesikko" is the Finnish name for the European mink."

I think it very likely NATO (especially the US and German navies) already have laid acoustic and other sensors in the Baltic.

The original SOSUS was better for open ocean detection https://en.wikipedia.org/wiki/SOSUS.

But under the US Integrated Undersea Surveillance System (IUSS) network smaller more sensitive acoustic, magnetic anomally and other sensors probably exist in the Baltic. Their main target would be Russian subs and ships. With the Russian threat growing IUSS in the Baltic is likely becomming more intense.

Regards Pete

Anonymous said...


Thanks interesting about the IUSS sensors. Upon reflection I can see that soem Swedish style subs might be quite useful for Finland now.

During the Cold War Soviet subs in their Baltic fleet were the main threat. But now the Russian Baltic fleet is down to one single Kilo class, whereas there are over 20 modern surface combatants.

There is a lot of north south merchant traffic across the Baltic between Poland and the Baltic states and Finland + Sweden and a lesser amount of east west trade between Finland and Sweden (they also have a rail link in the north). The Russian ships are mostly based in Kalingrad/Konigsberg now rather than St Petersberg so they could easily disrupt this trade.

The deepest part of the Baltic is that between Poland and Sweden, subs can definitely operate in this southern half of the Baltic. Swedish (or future Finnish) subs could be quite useful against Russian ships coming out from Kalingrad in this location.

Also (fun facts about the Baltic) it is a quite acoustically unusual sea. It is the least salty of the world’s seas, due to all the snow melt water, and fairly shallow overall (more than half ipof it is under 100 metres deep. So there won’t be lots of Sonar bouncing off the thermocline.

Pete said...

Hi Anonymous [at Jul 3, 2022, 9:33:00 PM] Baltic Subs and Undersea Sensors.

Yes, on "Swedish style subs might be quite useful for Finland now."

Sweden's submarine builder, Saab, for several years has had a small 1,000 tonne concept "A26 Pelagic" submarine variant which may be appropriate for the Finnish Navy - see https://gentleseas.blogspot.com/2017/09/saab-kockums-concept-proposal-of-three.html

The smaller the sub the better it can operate in shallower Baltic waters. Also small subs tend to be lower priced.

As well as Russia's one Kilo sub Russia deploys a range of relatively heavily armed corvettes in its Baltic Fleet - see https://en.wikipedia.org/wiki/Baltic_Fleet#Surface_Vessels_and_Submarines

The Russian corvettes represent a threat to Finland's Navy, merchant fleet and coastal towns/cities in corvette artillery range.

Saab also builds advanced and stealthy Visby-class corvettes that can inter-operate with Swedish Navy Visbys and together act as a counter to the Russian Navy - see https://en.wikipedia.org/wiki/Visby-class_corvette .

The beauty of the IUSS system is that complex sea conditions are surveyed by US ships and subs, then computer miodelled and then a variety of acoustic and confidential non-acoustic undersea sensors can be laid.

Acoustic sensors in the Baltic are not a new thing. From the 1950s and perhaps currently Sweden has maintained the Malsten acoustic arrays on the approaches to Stockholm harbour - see https://gentleseas.blogspot.com/2015/01/second-swedish-sighting-of-russian-mini.html

Regards Pete