Because those losses were due to non-combat like causes (scuttling during decomission, loss turing towing etc) they are irrelevant to the discussion of combat survivability.
You can make an argument regarding reliability and safety of the Soviet designs, but it is again irrelevant to this specific discussion.

Because with double hull and high strength pressure hull it is unlikelly that a hit by a lightweight torpedo would lead to flooding in multiple compartments. If anything Kursk shows that in order to achieve flooding of multiple compartments you need a very big explosion.

Technically no, Typhoons are both larger and have larger reserves. Kursk sank due to internal (and thus more dammaging) explosion of multiple 650mm torpedos which are by far more potent than a lightweight torpedo or even the classical heavyweight torpedoes.
Thus even that case is not illustrative of the expected combat survivability.

Why you think that. Is russian/soviet subs have greater buoyancy only during combat?
USN/UK subs have same "low" buoyancy reserve all the time. Statistically they should be sunken in accidents more often than russian subs.

That is a faulty assesment, because if you look at the losses of the subs they were due to the causes that were independent from boyancy reserves where those were availiable (ie excluding charlie class for example).

In fact in one such case (loss of the Mike class) the loss can be attributed to a feature that improves survivability to combat dammage (solid fuel gas generators for emergency blow), that feature is currently standard on Soviet/Russian desighns.

To recap my point - double hull and boyancy reserves allow the submarine to survive certain types of combat dammage (lightweight torpedo hit with a single compartment flooding) unlike the classical single hull, poorly compartmentalised US desighns without reserves, but does not magically make that sub unsinkable (though Oscars and Typhoons are as close to that as possible).
Nor does it affect the reliability and safety of the desighn, which is a separate matter entirely.

Simple maths, ot they are nukes or they cant damage my boat at all with a 210kg conventional warhead explotion at 120-180 yds. Period. Have you read any of the posts about the damage of the depth charges in the WWII in this thread?.

Citing Wikipedia:

"Although the explosions of the standard United States 600 lb (270 kg) Mark 4 and Mark 7 depth charge used in World War II were nerve-wracking to the target, an U-boat’s undamaged pressure hull would not rupture unless the charge detonated closer than about 15 ft (4.6 m). Placing the weapon within this range was entirely a matter of chance and quite unlikely as the target maneuvered evasively during the attack. Most U-boats sunk by depth charges were destroyed by damage accumulated from a long barrage rather than by a single charge. Many survived hundreds of depth charges over a period of many hours; U-427 survived 678 depth charges fired against it in April 1945."

https://www.reddit.com/r/AskHistoria...arges_in_wwii/

Here is link to interesting document - link

and here are some graphics:

http://i.imgur.com/H7tLTaU.jpg

Descriptions about pressure:

http://i.imgur.com/MOrDlIf.jpg?1
http://i.imgur.com/RQoIX6z.jpg?2

Document and graphics are about "Underwater explosion on a ship" - not submarine but i think it gives us some good reference.

It shows that 210 kg of TNT can't sink ship from distance 120-180 yds. In other hand, your damages was not massive. I think they responds 2-6 MPa.

I can't find information how strong nuclear warhead had shkval, but i think nuke explosion from that distances should sink your sub immediatly.

Conclusions:

- In RA shkval does little too powerfull damages from distances 120-180 yards but i think it is acceptable for "game purposes".
- damages you took definitely was not from nuke warhead

I agree that a nuke at that distance would result in immediate sinking. I also agree with both of your conclusions. The Skhval's current explosion would be consistent with a rather small nuke (<0.1 kiloton), but I feel the Shkval would have a much larger nuke (or at least it could) because it is a rather large torpedo. It seems likely Sonalysts modeled Shkvals this way for gameplay purposes, which I'm fine with.

EDIT: By the way, the stuff you posted is very cool :up:

I do not agree, we are talking of a WAR VESSEL!. Are a superb charts, but looking the distance and payload, the category falls to 2-4 (for a 300 kg payload, the Shkval only have 210Kg), for a ship is lighting lamps cracking and electronics, but THIS IS AN AKULA (Project 971), in the scale of less than 4 MPa it should not receive any damage at all, only a simple push. And by the way, the voices only reflected a small part of the damage I received, in fact the damage screen in the first test was complete full of red text, will repeit the test. If my radio antenna, radar and all the electronics broken were deployed is ok, but they were secured inside the sub tower.

In DW damages are completly random. I am sure with 45% most of them needs about 1 hour (max) for repair.

Sorry for joke but i cannot resist :)

...but:
http://i.imgur.com/Un1Wtxp.jpg?2

Yes, this is Akula, so?

Yes, I know that. Did you look to linked document?

Civilian vessels are safe with pressure 0-0,4 MPa
Warship are safe with pressure 0-2 MPa
(this is on second picture)

All time you said "damages was massive" but on YT you did not check list of damages and how many minutes takes repairing. You just quit mission!

From my experience i know that 45% of damages is not too much. Probably your submarine still was able to gain max speed, depth etc.

:haha: GREAT PIC!, but yes the Akula is something similar to Sparta in the sub world! :Kaleun_Cheers: and yes, I read the whole document is great!

2 MPa is ~ 20 atm or ~ pressure at 200m depth.

Ofc there is a difference between static and dynamic loads, but on low depths such a change in pressure that doesnt sound as all that lethal considering the crash dive depth of the desighn.

Morever, more or less post Alfa class the Soviet SSN/SSGN desighns were optimised (in terms of hydrodynamic shaping and structural desighn) to improve survivability against (nuclear) depth charges.

That is the key right there. :up: In the case of a localized explosion, such as a depth charge or conventional torpedo, as the shockwave moves, one part of the sub will be seeing this transient increase in pressure while another part will not. That pressure gradient is what creates damage.