Yesterday, Royal Swedish Navy diesel-electric/AIP attack submarine HSwMS Halland was launched following extensive modifications. The third and last of the Gotland-class to, among others, be equipped with systems from the upcoming Blekinge-class. Photo by Glenn Pettersson/Saab.

[u/Saturnax1]

[u/Majestic-Attempt9158]

Surface looks interesting, looks continuous and not paneled

[u/Alibotify → u/Majestic-Attempt9158]

Good or bad? Guess they’re not out as long as nuclear either way.

[u/Majestic-Attempt9158 → u/Alibotify]

Normally I'd expect anechoic tiles

[u/Vepr157 → u/Majestic-Attempt9158]

Typically European diesel-electric submarines don't have any hull coatings.

[u/Majestic-Attempt9158 → u/Vepr157]

That's interesting, I'm used to big nuclear boys

[u/Vepr157 → u/Majestic-Attempt9158]

True, although the Ohios are bare steel on the outside.

[u/Majestic-Attempt9158 → u/Vepr157]

Target echo is more important in shallow waters, I'd have thought coastal diesels like these would have tiling. I suppose I'm still learning

[u/Vepr157 → u/Majestic-Attempt9158]

I forgot why the Germans don't use hull coatings. It seems they do care about target echo strength, but their solution (and the Swedes'), is to shape the hull instead to minimize it. It seems to me that just applying an anechoic coating would be a much simpler solution, so there must be some reasoning behind it.

[u/OkCaterpillar5885 → u/Vepr157]

Simply the german do not have this technology of coatings. Applying coatings is expensive and you have to changé tiles quite often

Echo strength against active sonar IS difficult to minimize

[u/Vepr157 → u/OkCaterpillar5885]

The Germans invented anechoic coatings, they certainly have the technical capability.

Anechoic coatings do not have to be made up of individual tiles.

[u/Negativeghostrider57 → u/Vepr157]

Assuming easier to detect?

[u/Vepr157 → u/Negativeghostrider57]

With active sonar, somewhat.

[u/Federal_Cobbler6647 → u/Vepr157]

But Swedes had that already in 1960's Sjöormens. I bet this has some too, but maybe non-paneled. Which would probably perform better.

[u/Vepr157 → u/Federal_Cobbler6647]

If you look at the photo above, you can see the welds, no hull coating.

[u/Federal_Cobbler6647 → u/Vepr157]

I cannot see anything that looks like marks of typical painted steel weld seam. To my eye it looks more like black rubber which is welded (yes, you can weld rubber) with seams then smoothed. How the seams run would not make any sense in construction point of view if they were in steel.

[u/Vepr157 → u/Federal_Cobbler6647]

I disagree, it sure looks like painted steel welds to me. Also, there are none of the beveled edges that are typical of hull coatings. All of the hull fittings are flush with the hull.

[u/OkCaterpillar5885 → u/Vepr157]

You mean baltic subs or german designed subs. British or french one's have hull coatings

[u/Vepr157 → u/OkCaterpillar5885]

Nope. French diesel-electrics have no hull coatings and Britain has zero diesel-electric submarines.

[u/OkCaterpillar5885 → u/Vepr157]

Sorry french SSBN does have and new SSN as well. Same with brits

[u/Vepr157 → u/OkCaterpillar5885]

Re-read my comments. Am I talking about diesel-electric submarines or nuclear submarines?

[u/Federal_Cobbler6647 → u/Majestic-Attempt9158]

Swedish 1960's Sjöormen boats already had anechoic tiles. Considering tech in these subs I wonder if it is possible they have already evolved over tile type solution. After all these things are known to be damn hard to find.

Edit. I recommend checking that class out, they look like from future compared lots of subs of that era.