Project 877/636: Kilo class SSK

jhelb wrote:

walle83 wrote:Will have anyway, they are still in construction fase.

Still under construction? But SAAB did get this technology when they acquired Kockums, isn't it?

The AIP technology yes, but the submarines hasnt been launched yet. So to say that the A26 has the best AIPs is a bit premature.

AIP do make SSKs more capable, but so do improved performance batteries... at the end of the day if Russia needs a sub to remain submerged for long periods it can use an SSN.

For this reason they are not an enormous priority, but would be useful for use in subs of various types... even perhaps as a backup system on a nuclear powered sub for when the reactor is shut down... and uses like in satellites or space craft or use on other planets in fixed habitats.

Such systems would also be useful for storing electrical power in very low temperatures.

A solar array might generate electricity during winter but low temperatures means battery storage is a problem... using electricity from solar or wind generators in winter an AIP could use that electricity to convert normal water into hydrogen and oxygen which can be stored and either used in a gas turbine to generate electricity or put through the fuel cell to generate electric current for use... with the by product being hot water...

Work on EMALs cats will also lead to new technology working with electric currents and storing and using large amounts of electrical energy.

GarryB wrote:AIP do make SSKs more capable, but so do improved performance batteries... at the end of the day if Russia needs a sub to remain submerged for long periods it can use an SSN.

Rapid strategic and technological changes, such as the shift to littoral conflict or the extreme stealth of air independent propulsion (AIP) submarines, have eroded the nuclear advantage

AIP technology has improved significantly the stealth performance of a new generation of submarines at a fraction of the cost of a nuclear-powered boat. Even with improved batteries, diesel subs will still have to snorkel to clear the exhaust air, isn't it ?

With electro-catalytic fuel cells and the high energy density of Lithium-ion batteries, AIP submarines can operate at a patrol-quiet state or rest on the seabed for several weeks without surfacing. German Type 214 submarines can stay underwater without snorkeling for up to three weeks, traveling 3000 kms or more.

Rapid strategic and technological changes, such as the shift to littoral conflict or the extreme stealth of air independent propulsion (AIP) submarines, have eroded the nuclear advantage

AIP means more time underwater. That doesn't give the sub better caracteristics. The SSN can run at 30 knots always for its entire months of operation. The SSK will still be limited to very slow speeds and AIP will provide less time boost as the speed increase.

AIP is just a a way to stock more energy but is still very limited. Nuclear energy is infinite specially with new reactor that don't need refuel for the entire life of the submarine.

AIP technology has improved significantly the stealth performance of a new generation of submarines at a fraction of the cost of a nuclear-powered boat. Even with improved batteries, diesel subs will still have to snorkel to clear the exhaust air, isn't it ?

With electro-catalytic fuel cells and the high energy density of Lithium-ion batteries, AIP submarines can operate at a patrol-quiet state or rest on the seabed for several weeks without surfacing. German Type 214 submarines can stay underwater without snorkeling for up to three weeks, traveling 3000 kms or more.

AIP doesn't replace the diesel engines and main batteries. Once they used them they can still run on AIP for a certain amount of time but then they need to turn on diesel engines to recharge the batteries because AIP won't have enough power.

3000km for 3 weeks (21x24 hours) means to a speed of 6 km/h. That's far from SSN capabilities. Increase that speed and the 3 weeks will become 1 week under water.

Isos wrote:The SSN can run at 30 knots always for its entire months of operation.

SSNs require large reduction gears and a robust cooling system to maintain safe operation of the reactor. Noisy pumps circulate cooling water around the reactor core at all times, then pump the same cooling water back into the ocean, leaving nuclear submarines with a much larger infrared heat signature.

Because of the need to cool the reactor, SSNs prefer to keep to deep, cold water unless operating on station.

Not all undersea missions require nuclear power. Diesel submarines could be used for coastal defense and antisubmarine warfare

SSNs require large reduction gears and a robust cooling system to maintain safe operation of the reactor. Noisy pumps circulate cooling water around the reactor core at all times, then pump the same cooling water back into the ocean, leaving nuclear submarines with a much larger infrared heat signature.

Because of the need to cool the reactor, SSNs prefer to keep to deep, cold water unless operating on station.

Not all undersea missions require nuclear power. Diesel submarines could be used for coastal defense and antisubmarine warfare

I just said SSK can't replace SSN. They have their usefulness specially in coastal water with the protection of friendly ships and air force.

A SSK is more stealthy but if detected it will be dead as it has very low speed and can't stay underwater for long (unless if it goes very slowly but then it is still in danger). For power projection you need SSN.

Isos wrote:A SSK is more stealthy but if detected it will be dead as it has very low speed and can't stay underwater for long (unless if it goes very slowly but then it is still in danger). For power projection you need SSN.

SSN because of their large infra red signature will be easier to detect.

I don't know of too many technologies that have been designed to reduce infra red signature of SSNs drastically. So they remain a big target.

Plus US navy has sensors embedded on the ocean floor at critical choke points to detect nuclear and conventional submarines. That's why Russian SSGNs and SSBNs are designed to fire SLBMs from underneath ice sheets.

Yet USN uses only SSNs. Infrared detectors would work if the sub is near the surface but a yasen or an akula at 200m is safe. Main tool used against subs is still the sonar and modern nuclear subs are as quite as diesel subs.

And contrary to wwhat you think stealth is not the only way to fight. Russian emphazize the raw caracteristics like max operating deapth, spead, long range weapons, countermeasures ... rather than betting on only stealth.

Why do you think SSNs pump lots of hot water into the sea?

A nuclear propulsion system is not about keeping the nuclear reactor cool it is about generating steam to drive turbines and generate power... the nuclear reactor is there to boil water essentially...

Very basically a nuclear reactor has fuel rods that heat up when exposed to each other... which can be directly used to boil water... but you can lower the fuel rods into a matrix of other materials that absorb the active energy elements and stop it from getting hotter... in fact they cool down on their own.

By moving the fuel rods in and out of the control material you can manage the temperature they get to... but considering the system uses super heated high pressure water to generate steam to power turbines... why do you think they would want to keep the water cool?

An Alpha class submarine has a liquid metal reactor... do they dump liquid metal into the ocean and take on sea water to cool down that reactor?

When the coolant in a liquid metal reactor gets cool it solidifies and the entire reactor is screwed... you can't turn them off even at shore... it is like turning off the rotating section on a concrete mixer truck... if that concrete hardens the rear bowl becomes useless and needs to be completely replaced.

SSKs are rather quiet but don't have anything like the sonar performance of a SSN... except the new Lada class SSKs which have greatly improved sensors... they also can't move very far or very fast while remaining quiet.

Short range local defence in shallow waters they are ideal but not irreplaceable... and there are natural circulation reactor cooling systems that don't require pumps...

Heat is about volume so the more sea water they pump through a hot section the cooler the hot section gets but also the less heat is transferred to each litre of sea water. So to cool down a 200 degree C section if you pump 500 litres of water that water might go into the sea boiling but the section is reduced to perhaps 80 degrees C which is good enough... if you pump the water faster and for longer the water going through wont be heated to the same high temperature though more water will be needed for the job.

What I am saying is that pumping tens of thousands of litres through when operating at 500m depth the 4 degree water might be heated to 10 degrees and therefore rise to 100m where the ambient water temperature is 10 degrees... but how could you tell?

To notice you would need to have a temperature sensor in the water near the sub...

If you think a warm water plume on the surface marks where a sub is... well sure... but it could also be heat from an underwater volcanic vent, or indeed a whale fart, or just natural currents stirring warmer waters from different depths...

A SSK is more stealthy but if detected it will be dead as it has very low speed and can't stay underwater for long (unless if it goes very slowly but then it is still in danger).

that's why the VMF will use them only in the littorals under protection of surface ships, shore based AShMs, & aviation, to limit/interdict that danger. Their LACMs also have enough range to be used from the home waters.

That's why Russian SSGNs and SSBNs are designed to fire SLBMs from underneath ice sheets.

SSGNs don't carry any SLBMs & their normal deployment areas r not under ice, unless they'll transit to/from the Pacific.

Isos wrote:Yet USN uses only SSNs.

They are replacing diesel subs with long range UUVs and short range UUVs.

https://www.lockheedmartin.com/en-us/products/orca-extra-large-unmanned-underwater-vehicle-xluuv.html

Isos wrote:Russian emphazize the raw caracteristics like max operating deapth, spead, long range weapons, countermeasures ... rather than betting on only stealth.

Which countermeasures?

If Russian Subs are operating at depths of 200m like you said, then maybe they are outside the range of depth charges, but enemy subs armed with torpedoes can still target them.

GarryB wrote:Why do you think SSNs pump lots of hot water into the sea?

The energy from fission is transferred to the water.

The fission process creates high speed neutrons and fission products. These will interact with the fuel matrix and the water, slowing down. In the process they will transfer their kinetic energy to the fuel and the water. The fuel will heat up and will transfer its energy to the water through conduction and convection. Hence, the water will heat up

https://en.wikipedia.org/wiki/Nuclear_marine_propulsion#Basic_operation_of_naval_ship_or_submarine

GarryB wrote:except the new Lada class SSKs which have greatly improved sensors

Sonars will be improved. What are the other sensors that you are referring to?

They are replacing diesel subs with long range UUVs and short range UUVs.

How could they replace diesel subs when they don't operate them. UUV is a totally new stuff replacing nothing.

US submarine force is still composed only of nuclear subs.

Which countermeasures?

If Russian Subs are operating at depths of 200m like you said, then maybe they are outside the range of depth charges, but enemy subs armed with torpedoes can still target them.

They can go down as far as 600m to evade sonar detection. They can go fast to reduce the engagement zone of enemy sub and be able to escape, they have very good countermeasures in form of small torpedo-like devices that imitate the sub signature.

New husky is also supposed to have hard kill anti-torpedo torpedo like the paket NK.

They have kalibr missiles with a torpedo that can target a sub 50km away in 2 or 3 minutes. An enemy torpedo will need half an hour to reach its max range. Once they detect the launch of a torpedo they can launch their own kalibr, enemy sub won't have time to escape.

Isos wrote:How could they replace diesel subs when they don't operate them.

The point that I was trying to make was they don't use diesel subs, instead US Navy is developing large, long range unmanned subs.

Isos wrote:they have very good countermeasures in form of small torpedo-like devices that imitate the sub signature.

Which countermeasure is this that you are referring to?

Which countermeasure is this that you are referring to?

I don't have any lonk. Maybe you could find on specialized forums.

Try HIsuton website they discribe very well subs. There are picture of russian subs showing the hatches for such countermeasures.

They are replacing diesel subs with long range UUVs and short range UUVs.

The USN doesn't have any diesel subs... that is why they like to train with smaller countries that do have them...

The energy from fission is transferred to the water.

The fission process creates high speed neutrons and fission products. These will interact with the fuel matrix and the water, slowing down. In the process they will transfer their kinetic energy to the fuel and the water. The fuel will heat up and will transfer its energy to the water through conduction and convection. Hence, the water will heat up

A nuclear reactor is used to boil water to drive turbines to generate electricity... in such a system why would it need to cool the water down? Cold water doens't drive turbines and wont generate electricity. To cool down the reactor you turn it down which lowers the fuel rods into the control matrix and stops the fission reaction which stops generating heat.

Introducing cold water into the system reduces energy... why?

The water in a pressurised water cooled nuclear reactor is a closed circuit... the high pressure means instead of boiling at 100 degrees C it boils at much higher temperatures which makes the steam much more energetic. If they have to cool anything down they could expose the pipes that the high pressure coolant is flowing through to sea water... but they could control the heat of the sea water going in to the sea by changing the amount of water being exposed and the time it is exposed for.... think of a hot bath of water and a tube that is say 20mm thick that pumps water up out of the bath and down beside the bath and through a swimming pool on the ground outside the window. The water in the bath is 80 degrees C, but the water in the swimming pool is only about 3 degrees so the bath water in the pipe is about 80 degrees as it moves through but where the pipe goes in to the swimming pool the temperature of the pipe is lowered by the cold water in the pool. The water in the bath is hot but not hot enough to heat up the water in the swimming pool by very much... but with a constant flow of bath water through the swimming pool the bath water will be quickly cooled, but because of the volume of the water in the swimming pool the swimming pool might only get a few degrees warmer.

Go back to the sub... if there was a reason they needed to cool the water they could use a radiator with a huge surface area that is sealed so no water from the sub leaves the sub... but cool sea water enters the sub and cools the liquid in the radiator and then goes back in to the ocean.

IR is used to detect submarines... BUT ALL SUBMARINES. When any type of submarine moves through the water while submerged it disturbs the water and mixes water in different layers.

Pressure effects the temperature at which water freezes and at which it gets heavier or lighter so normal sea water consists of multiple layers but with depth comes increased pressure which changes density so it is not the case that the surface water is the warmest and the bottom layer is the coldest.

A large object like a submarine can stir water from different layers and send it rippling up to the surface... so you get an IR trail because warmer water from different layers breaks the surface so you can see a warm trail on the surface with a thermal device... of course it doesn't always work efficiently sometimes the water stirred up is mixed temperatures and not easy to see... some times it is because a pod of whales or a large school of fish have disturbed the layers... it is not a reliable way to hunt subs...

Sonars will be improved. What are the other sensors that you are referring to?

The Soviets/Russians had all sorts of different sensors on their subs... many of which are still secret... I don't pretend to know all about them.... needless to say look at this image and tell me what sort of sonar or radar it is...

they have very good countermeasures in form of small torpedo-like devices that imitate the sub signature.

They had three for export in the early 2000s... the MG-74ME is a multipurpose system that can create noise to jam enemy sonar and torpedo homing systems and also attract torpedos by creating a target simulating a sub signature to attract passive homing weapons. It can use high power sonar emissions, or it can mimic a specific sub type and manouver in a way that a normal sub would to evade torpedoes and anti sub formations.

Used for training but can also be used as a countermeasure.

There is also the Berilly-E self propelled multirole automated sonar countermeasures system that can basically do similar things, and then there is also the Akhilles self propelled target/submarine simulator that basically can simulate a ship or sub for the purposes of training but can also be used in combat... all three are 533mm calibre and can be launched from standard sub and ship mounted torpedo tubes of that calibre.

I am sure they have something like this on their newer subs... as I said these three weapons are listed for export in a book released in 2000.

Isos wrote:needless to say look at this image and tell me what sort of sonar or radar it is...

I don't know. What do you think it is?

Isos wrote:Try HIsuton website they discribe very well subs. There are picture of russian subs showing the hatches for such countermeasures.

Is this guy Russian? Else I don't think they will have authentic information about anything Russian.

Is this guy Russian? Else I don't think they will have authentic information about anything Russian.

He follows the manditory western stereotypes of Russian aggression... you know... they do it because they are bad... they have no legitimate interests or self defence needs and anything they do is aggression aimed at the innocent pure west... but certainly seems to be a popular source for some members here...

I remember during the Cold War when any information you got out of the Soviet Union you assumed anything good was a lie and anything bad must be the truth, but retaining that attitude today is just ignorance... but then Boris and Trump and Micron prove ignorance is popular in the west...

Is this guy Russian? Else I don't think they will have authentic information about anything Russian.

He makes very nive articles about subs without any political arguments. He takes opensource data to do so and is not biased.

Russians have no more authentic information than him because thise things are secret.

Tsavo Lion wrote:
Exactly, & they didn't want to delay construction of Kilos or waste time on developing the Lada needed to boost their SSK #s in the BSF, BaltF, NF & PF.

How many Kilos are now under construction?

Why is Russia constructing so many kilos? Is it for export? Already 14 SSNs are there so no major need for SSKs.

3 +2 more contracted: https://ru.wikipedia.org/wiki/%D0%9F%D0%BE%D0%B4%D0%B2%D0%BE%D0%B4%D0%BD%D1%8B%D0%B5_%D0%BB%D0%BE%D0%B4%D0%BA%D0%B8_%D0%BF%D1%80%D0%BE%D0%B5%D0%BA%D1%82%D0%B0_636_%C2%AB%D0%92%D0%B0%D1%80%D1%88%D0%B0%D0%B2%D1%8F%D0%BD%D0%BA%D0%B0%C2%BB#%D0%9F%D1%80%D0%B5%D0%B4%D1%81%D1%82%D0%B0%D0%B2%D0%B8%D1%82%D0%B5%D0%BB%D0%B8_%D1%81%D0%B5%D1%80%D0%B8%D0%B8

The PacF, among the other fleets, was neglected for a long time & needs to be strengthened. It could find a good use for new SSKs.

jhelb wrote:

Tsavo Lion wrote:
Exactly, & they didn't want to delay construction of Kilos or waste time on developing the Lada needed to boost their SSK #s in the BSF, BaltF, NF & PF.

How many Kilos are now under construction?

Why is Russia constructing so many kilos? Is it for export? Already 14 SSNs are there so no major need for SSKs.

14 split in 2 because northern and pacific fleets are far away one from the other.

7 SSN to counter NATO and 7 to counter Japan/China/USA on the other side is not enough. They need at least 20 of them and upgrade all their Oscar 2 which are still very good.

Kilo are good for close waters but with cruise missile having longer ranges than before they need more and more SSN to counter destroyers that would launch their missiles hubdreds km away something kilos can't do. And don't forget that real kalibr carriers are Yasens not kilos. A yasen can launch 40-70 kalibr very fast and go away very fast too.

Kilos are great for littoral waters. There can´t be enough.

jhelb wrote:...Why is Russia constructing so many kilos? Is it for export? Already 14 SSNs are there so no major need for SSKs.

14 SSNs is nowhere near enough plus it's a completely different mission profile and location

A lot of Soviet-era Kilos turned out to be in bad shape (this was reported recently) which means they will need replacement ASAP

Production of Lada-class is still warming up which means that they will be ordering extra Kilos to plug the gap until Lada production pace catches up

Isos wrote:...And don't forget that real kalibr carriers are Yasens not kilos.

Actually Yasens are supposed to deal with surface ships which means they will be carrying Onyx

Kilos are prime carriers for Kalibrs, land based targets for conventional cruise missiles are not as high priority and are rarely as time sensitive as surface ships of peer nations and that means that Kilos and Ladas are more than adequate

Syria has demonstrated this

Isos wrote:7 SSN to counter NATO and 7 to counter Japan/China/USA on the other side is not enough. They need at least 20 of them and upgrade all their Oscar 2 which are still very good.

7 SSN for USA and China? Not enough, not even close. Ok for defending against other smaller, weaker nations like South Korea, India, Pakistan etc but NOT against China.

PapaDragon wrote:Production of Lada-class is still warming up which means that they will be ordering extra Kilos to plug the gap until Lada production pace catches up

Without AIP they want launch Lada.

There was this submarine called S-1000 that Rubin was supposed to design with Fincantieri of Italy. Not sure how much progress that project made. Hardly read anything about that in the Russian media.

7 SSN for USA and China? Not enough, not even close. Ok for defending against other smaller, weaker nations like South Korea, India, Pakistan etc but NOT against China.

Russia doesn't need to have 1 for 1 sub to face USA. US can't risk a full war with Russia and have its carriers destroyed because then China would be free taking all the land around the south China sea it wants.

Russians also have tu-22M, oscars ... to deal with ebemy fleets.


China can't face Akulas and Yasen. Even 5 of them would be deadly for them.