Project 971: Akula class

High speed maneuvering flaps

Sonar Array

Water intake for quiet cooling

Silent running electric motor

SOKS sensor on sail

SOKS sensor on hull?

Full report from the modernization of aculas with pics and captions

looking to google earth or Yandeks show Akula K-335 at Nerpa (2013/14). Are there any pictures or news about the overhaul at Nerpa of that boat?

George1 wrote:Full report from the modernization of aculas with pics and captions

Wish they can get their upgrades and refit On-time.

Once in the dock, they'll be cut clean.. refuelled, machineries got repair and re-balanced, new technology inserted. After that the boat will be "reunified" and pressure hull re-welded. old anechoic coatings got stripped out and replaced anew.

Boom.. Bars re-birth perhaps more silent than what it was before.

rambo54 wrote:looking to google earth or Yandeks show Akula K-335 at Nerpa (2013/14). Are there any pictures or news about the overhaul at Nerpa of that boat?

K-335 is Gepard class. I havent seen any info for this one.
I know from info in sites that the akulas below are in modernization status:
Kashalot
Bratsk
Leopard
Samara

Kashalot is not in modernization. It has been laid up waiting repairs for years. Now India might be leasing it.

Submarine "Kuzbass" will return to the fleet before the end of the year

http://flot.com/2015/%D0%97%D0%B2%D0%B5%D0%B7%D0%B4%D0%B07/

Kashalot will be leased to India.

http://tass.ru/en/defense/831746

well Russian navy has so many nuclear submarines that gives them the ability of leasing them??

Russia's Gepard Nuclear Sub Returns to Northern Fleet After Servicing

The nuclear-powered attack submarine will undergo a naval combat training course shortly.

MOSCOW (Sputnik) — The Russian nuclear Gepard (Cheetah) submarine has returned to the country’s Northern Fleet after the restoration of technical readiness, the fleet’s spokesman said Saturday.

"During its time in the factory, the nuclear submarine received a series of services, significantly extending the vessel’s operating life and continuing its future use in the Arctic conditions," Сapt. 1st Rank Vadim Serga said.

The vessel will undergo a naval combat training course shortly.

The Gepard vessel is a third-generation Project 971 (Akula class) nuclear-powered attack submarine. It was built in 2001.

Akula-class submarines feature very low acoustic signatures and can carry up to 12 submarine-launched cruise missiles with nuclear warheads and a range of 3,000 kilometers (1,860 miles) in addition to anti-ship missiles and torpedoes.

Read more: http://sputniknews.com/military/20151128/1030903487/russia-gepard-submarine.html#ixzz3sm6ktgPB

George1 wrote:Russia's Gepard Nuclear Sub Returns to Northern Fleet After Servicing

The nuclear-powered attack submarine will undergo a naval combat training course shortly.

MOSCOW (Sputnik) — The Russian nuclear Gepard (Cheetah) submarine has returned to the country’s Northern Fleet after the restoration of technical readiness, the fleet’s spokesman said Saturday.

"During its time in the factory, the nuclear submarine received a series of services, significantly extending the vessel’s operating life and continuing its future use in the Arctic conditions," Сapt. 1st Rank Vadim Serga said.

The vessel will undergo a naval combat training course shortly.

The Gepard vessel is a third-generation Project 971 (Akula class) nuclear-powered attack submarine. It was built in 2001.

Akula-class submarines feature very low acoustic signatures and can carry up to 12 submarine-launched cruise missiles with nuclear warheads and a range of 3,000 kilometers (1,860 miles) in addition to anti-ship missiles and torpedoes.

Read more: http://sputniknews.com/military/20151128/1030903487/russia-gepard-submarine.html#ixzz3sm6ktgPB

hmm any idea so how many 971s are operational in RN and how many to be still refurbished?

GunshipDemocracy wrote:

George1 wrote:Russia's Gepard Nuclear Sub Returns to Northern Fleet After Servicing

The nuclear-powered attack submarine will undergo a naval combat training course shortly.

MOSCOW (Sputnik) — The Russian nuclear Gepard (Cheetah) submarine has returned to the country’s Northern Fleet after the restoration of technical readiness, the fleet’s spokesman said Saturday.

"During its time in the factory, the nuclear submarine received a series of services, significantly extending the vessel’s operating life and continuing its future use in the Arctic conditions," Сapt. 1st Rank Vadim Serga said.

The vessel will undergo a naval combat training course shortly.

The Gepard vessel is a third-generation Project 971 (Akula class) nuclear-powered attack submarine. It was built in 2001.

Akula-class submarines feature very low acoustic signatures and can carry up to 12 submarine-launched cruise missiles with nuclear warheads and a range of 3,000 kilometers (1,860 miles) in addition to anti-ship missiles and torpedoes.

Read more: http://sputniknews.com/military/20151128/1030903487/russia-gepard-submarine.html#ixzz3sm6ktgPB

hmm any idea so how many 971s are operational in RN and how many to be still refurbished?

7 in service, 3 under refurbishment

George1 wrote:7 in service, 3 under refurbishment

You mean the other way around? 3 in service, 6 in refurbishment.

In service: Pantera, Tigr and Gepard. All with the Northern Fleet, based in Gadzhiyevo.

In refurbishment in Severodvinsk: Bratsk, Samara, Volk, Leopard

In refurbishment in Bolshoy Kamen: Magadan, Kuzbass

Inactive: Kashalot, Vepr

At least 6 submarines of the class have contracts to be upgraded to 971M level. We know for sure that Leopard is the first one, Samara & Bratsk are also very likely to become 971M. The rest are unconfirmed, but I expect probably Volk and Vepr to follow. Kashalot isn't coming back. Magadan & Kuzbass might get a VTG, but maybe not the whole 971M works. Not enough information at this point.

artjomh wrote:

George1 wrote:7 in service, 3 under refurbishment

You mean the other way around? 3 in service, 6 in refurbishment.

In service: Pantera, Tigr and Gepard. All with the Northern Fleet, based in Gadzhiyevo.

In refurbishment in Severodvinsk: Bratsk, Samara, Volk, Leopard

In refurbishment in Bolshoy Kamen: Magadan, Kuzbass

Inactive: Kashalot, Vepr

At least 6 submarines of the class have contracts to be upgraded to 971M level. We know for sure that Leopard is the first one, Samara & Bratsk are also very likely to become 971M. The rest are unconfirmed, but I expect probably Volk and Vepr to follow. Kashalot isn't coming back. Magadan & Kuzbass might get a VTG, but maybe not the whole 971M works. Not enough information at this point.

Gepard was the last built in 2001 so you would expect an upgrade there.

artjomh wrote: You mean the other way around? 3 in service, 6 in refurbishment.

In service: Pantera, Tigr and Gepard. All with the Northern Fleet, based in Gadzhiyevo.

In refurbishment in Severodvinsk: Bratsk, Samara, Volk, Leopard

In refurbishment in Bolshoy Kamen: Magadan, Kuzbass

Inactive: Kashalot, Vepr

At least 6 submarines of the class have contracts to be upgraded to 971M level. We know for sure that Leopard is the first one, Samara & Bratsk are also very likely to become 971M. The rest are unconfirmed, but I expect probably Volk and Vepr to follow. Kashalot isn't coming back. Magadan & Kuzbass might get a VTG, but maybe not the whole 971M works. Not enough information at this point.

Thanks. So leasing Kashalot (inactive )will not hurt much Russian Navy? As for refurbishment to M level means functionality not old avionics will be used?




BTW did you have a chance to check this:
http://sputniknews.com/world/20151109/1029839390/us-magazine-russia-weapons-notice.html

last sentence:
writes Majumdar, whose attention was also drawn by the development of two new next-generation nuclear submarines, to replace the Oscar-class SSGN and Sierra-class submarines.

Last year you mentioned something about this if I remember correctly. any more news on topic (that will not cause immediate visit of FSB

artjomh wrote:

George1 wrote:7 in service, 3 under refurbishment

You mean the other way around? 3 in service, 6 in refurbishment.

In service: Pantera, Tigr and Gepard. All with the Northern Fleet, based in Gadzhiyevo.

In refurbishment in Severodvinsk: Bratsk, Samara, Volk, Leopard

In refurbishment in Bolshoy Kamen: Magadan, Kuzbass

Inactive: Kashalot, Vepr

At least 6 submarines of the class have contracts to be upgraded to 971M level. We know for sure that Leopard is the first one, Samara & Bratsk are also very likely to become 971M. The rest are unconfirmed, but I expect probably Volk and Vepr to follow. Kashalot isn't coming back. Magadan & Kuzbass might get a VTG, but maybe not the whole 971M works. Not enough information at this point.

Vepr is the most modern after Gepard (1995 commissioned) and its inactive?
I also thought that Magadan, Kuzbass and Volk have finished refurbishment

George1 wrote:Vepr is the most modern after Gepard (1995 commissioned) and its inactive?
I also thought that Magadan, Kuzbass and Volk have finished refurbishment

Vepr exhausted fuel and was put in reserve.

The rest are nowhere near finished. They haven't really even started on them. Kuzbass, for example, is still sitting pierside, not in dock.

ZVEZDA was lagging so hard on 971 repairs that the Navy transferred Samara and Bratsk to Zvezdochka. IIRC, in Pacific Fleet, priority has been given to 949A upgrades.

Not that Zvezdochka will get to them any faster. Zvezdochka is currently working on Leopard, Volk will get some dock time soon to examine the hull, and Samara/Bratsk have only just entered the repair pipeline, they won't see the inside of the repair shop for a long time yet.

Kashalot is a goner. Even if they don't sell it to India, I don't think there is any interest in getting it back into action again, unless some funds miraculously start falling from the sky or oil gets to $200/bbl. Like I said, there is contract for only six 971M upgrades + maintaining some of the newer 971s.

Medvedev examined modernized nuclear submarine K-419 "Kuzbass"

So Kuzbass is ready for sail

Hello!
Does anyone know more about SOKS, what it is, how it works(just a principle of it`s work)? I think it is classified parameters of this device but I think, it is not classified information about principle of it¨s work. What is puzzled me, it is information what is circulating on Internet and it is sometimes contradicting. Anything what I can say that I know of this device is, it is not based on sound.
And if it is so good, why is not put in use on other submarines or surface ships? Is it dimensions so big to be put on smaller submarines or energy consumption is to big for non nuclear submarines?

chinggis wrote:Hello!
Does anyone know more about SOKS, what it is, how it works(just a principle of it`s work)?

As the name suggest, SOKS is a wake homing detection system.

It works on the principle of detecting the changes in temperature and pressure due to turbulence (the bubbles) in the ship's wake. The detector is optical, usually a directed laser.

More specific details are above everyone's paygrade here.

And if it is so good, why is not put in use on other submarines or surface ships?

There were wake detectors on surface ships as well, for example MI-110K and MI-110R on old cruisers (working on different principle). Whether there is a wake detection system on newer ships is, once again, above the security clearance levels of everyone on this forum.

Using lasers under water is limited to about 180 meters in range under pure salt water conditions.  But most of the oceans
have sufficient surface biotic activity that there is a detritus rain and dissolved organic matter that will limit this range to well
under 100 meters even below 100 meters depth (there is remineralization of the organic matter particulates and in solution and
their concentration decreases with depth).  

Of course the wake will have some life to it and will not die off right after a submarine leaves a given area. But it will still
have a rather short life and there will be turbulence from other sources as well. Considering the size of submarines this seems
like a limited utility system over most of the ocean regions.

An addendum to the light attenuation in seawater. Blue-green light that would be used since it has the least absorption and
hence farthest penetration, attenuates at between 0.155 and 0.5 dB/m. This should be compared to the 0.24 dB/m attenuation
of visible light in dense fog with a visibility of less than 50 meters. But there is a cheat here. The 0.155 to 0.5 dB/m only
applies for Jerlov type I seawater with the lowest biotic matter concentration (0.03 mg/m^3). In Jerlov type III seawater
(3 mg/m^3) the attenuation is over 4 dB/m.

The submarine action is not happening 1 km below the surface where the biotic matter concentrations are the low. It is
happening around the thermocline or the base of the mixed layer. Biotic matter concentrations are near maximum at these
depths for that location. Different parts of the oceans have different surface biotic activity levels.

I'm not hydrodynamicist, but I've been told that the vortices persist for several hours, which is how long range detection is possible.

Since SOKS is a purely passive system, the sensor operator will be measuring the "strength" of the return, thus allowing more precise detection.

It's like following bread crumbs...

Yes, and what I understand it is, when ships propeller stir the water, differences in temperature mixed water and not mixed have a long time of decay, it is like a power tube in physics in Croatian we are call it silocijev. It is like a tube in which all vectors of force have a same vector. For laser, I think it is a light source just for looking for bio luminescence what is caused by mixing waters with propellers and for looking for bubbles made from cavitation.
I can not tell you where I am read confession from navy pilot who confess that he find its way to mother ship in dark night just looking it on shades of sea. He claim that he is able to spot a differences in shades 100 miles away from ship. It is hard to believe, but it is possible in some good conditions.
And for measuring temperature, it is possible to make a precision thermometer in backyard or in garage, so in that I can believe.

I agree there will be eddy persistence and that this is worthwhile detection system to implement. But it has
limits. Above the thermocline is the mixed layer which has too much eddy flux and any submarine wake will
be erased quickly. Below the thermocline the submarine wake signature will be distinct and persistent.
But there will be regions where the mixed layer is very shallow (e.g. below the Arctic Sea ice it is basically
absent).