I respectfully disagree on this point. Commodore Ward my ex CO spoke of this on occaison. Russian Subs were designed to go deeper to flee the MK-48. The threshold of a conventional torp is affected by water pressure. But a nuclear warhead it actually aids its intention and design. It dramatically increases water pressure. The goal is to implode the enemy with pressure produced by shock waves. Not to incinerate them.

That hurts ouch. I guess I've to spend more time with SC.

I just used that whole "Matchstick" thing as an example on how people think about nuclear weapons. I didn't mean to imply a SUBROC was ment to incinerate its target (at least when used against subs)

Well I think your CO got it backwards. Russian subs have always been designed to go deep, along with speed its the edge they have always had over our subs. The November had a 100 meter depth advantage over its American counterparts and the Russians have only gained on us in that area. The MK-48 was what was redesigned to compete with (the assumed) capablites of the Alfa. Of course the SUBROC predates the MK-48 so if Russian subs were being designed to defeat the current us ASW weapons of their era they were being designed to defeat the SUBROC and ASTOR both nuclear weapons, since the MK-37 could (unless fired from very close range or in the baffles) be simply out run.

I'm not totaly sure but it seems logical that increased water presure would have a negitive effect on the yeld of a nuclear weapon, simply from the explosive (kenetic) force having to push though more matter. Or maybe I'm thinking of thermal energy having to fight though pressure while kenetic energy would be aided by it. Do we have any phisics students out there? :hmm:

While the pressure of waters gets higher, density does not (or just a very little) because water can't be compressed (much). It is very different from gasses in this aspect.
Also both density and pressure actually makes the sound (or shockwave) travel faster and better.
I guess the pressure would add to the shock when it comes to overcoming stress limits.

Just a little interesting sidenote. It seems those assumtions where not that far off after all. I just read Rising Tide, where a former Alfa skipper talks about diving the boat to 3000ft.

Didn't the alfa have a hull of pure titanium ?
A very fine and costly piece of soviet engineering.
Why do american subs have to be so conservative. All the maverick designs came from the east. :p

And why did the Russians never put their titanium hulled submarine into full fledge production ? instead their backbone attack SSN were the Victors and now the Akula(Bars) class which is steeled hulled. I guess that tells us something....something prevented the Russians from putting its titanium hulled sub into full production imo.

The alfa I think I read it somewhere once went past right into a middle of NATO fleet exercise in high speed and deep depth. It was diving so deep that no weapon could touch it. It was very loud though so everyone could hear it. That was the event that sparked the development of the ADCAP I think. But I believe everyone here knows this story.

That story's new to me.

AFAIK, the Russian Sierras are the modern-day version of the Alfas, only much quieter and without the replaceable reactor core. No mass-production, once again.

But, going backwards, Alfas and Sierras can dive to that depth to evade attacks. Fine. I'm wondering, though, what they could do down there. 3000 feet sounds far deeper than what Russian torpedos can do, and while a titanium pressure hull can stand that, I'm not sure about an opened torpedo tube. So they could go super-deep for evasion, but for attacks they'd have to pop up to within the Mk48's envelope. Am I right?

yep! You need to have enough air pressure to implulse the fish out of the tubes. they would have had to come to shallower depth..

I wonder what the tactical implications are from being able to dive into the deep sound channel. In my limited understanding of sonar this should give you a nice boost in detection range.

I guess deeper operating depth also give your sub generaly greater flexibility in utilizing layers.

Yes, this made the Alfas (just as the Papa, Mike and the Sierra Class) immune to MAD detection from aircraft. And I guess also against magnetic proxy fuzes on torpedos.

A real pity this feature is not modelled in the "unspeakable mod". :cry:

Mostly cost. For the Alfas, they were also let down by their primitive surroundings - their bismuth-cooled plants might have been a cooler idea if their base infrastructure had a more reliable electrical supply.

Another factor is that they resolved the problems of using High-Yield steels. The yield ratings of the pressure hull steel on the Akula is roughly equivalent to HY-140 (100kg/mm^2 - do the conversion to pounds per square inch). This at a time when American (688s) were using HY-80 and they were thinking of HY-100 for Seawolf. With that steel, 600m class test depths (similar to Sierra, though one step short of Mike) became feasible at a reasonable mass penalty ... the Soviet's next decision is obvious...

The whole Alfa diving depth thing is pretty funny. Apparently Based on observations, the Americans (NATO?) assigned a high depth rating for the Alfa. Then the Cold War ended and the Russian sources came out which suggested a much lower depth, such as a "working" depth of 320-350m and a "maximum" depth of 400 or so (AFAIK, nobody said "crush"). The Americans believed them over their observations and all the sources are re-written, and now we have testimony again :)

I think the real problem is what Stuart Slade once uttered in his article about Alfas (it was in Warships1.com, but some time ago the entire site became unavailable even in the Wayback Machine and so it is now lost unless someone stashed a copy). IIRC, he mentions about how of loss of control at high (Alfa) speeds will cause a submarine to plunge very far below its depth, and this requires a high margin of safety. This will provide a reason for the Russians to write a very conservative working and maximum depth, while leaving the Russian Captains the margin (since the hull strength is there) to dive deep at their own risk (which is minimal if they aren't travelling at high speed at the same time).

The skip may have been referring to the MK-37. We had 48's then and the ADCAP was in developement, basically to go deeper to get the deeper diving boats. But I can tell you that a permit class boat could go about 300 to 400 feet deeper that the Novembers. I believe the Skipjack class was about on even keel with the test depth of the Novemebers.

Goldorak it is very possible to make a sub in DW undetectable by MAD sensor.

Well, given that Wiki isn't a dedicated naval source, I'm not that certain about how much to trust it on this matter.

But apparently, just because the Alfa has a titanium hull doesn't mean it's MAD-proof, it gives it a reduced signature.

Quoting from the Wikipedia MAD page:

Does any of the sonar gurus feels able to valuate the ability of some russian subs to dive into the deep sound channel? And does it still make a difference today with most subs having a towed array that can be droped this deep?