Kirov Class CONAS Powerplant Discussion

[whatismoo]

So I was reading up on Projects 1144 and 1165 again over on the Otvaga2004 site (the old Atrina articles), and noticed something interesting - the surface to air and surface to surface missile additions to 1144 predate the merger, which was more of a pro-forma "we didn't actually *cancel* the program we spent so much money on, we merged it into this other program".

Project 1144 and 1165 started out as "one ship does ASW, the other keeps the enemy off it", but because of the sheer size of 1144 due to having the nuclear reactor(s) *and* a conventional powerplant on top, there was so much room for extra stuff that everyone basically went "if it's cruiser sized, it should have cruiser weapons". Which means that just like Project 1165 went through "Malakhit, Korshun and Volna"; "Bazalt, Kvant and Osa-M", and "Granit, Fort and Osa-M" phases, so did Project 1144. Sadly, we only have the "Bazalt, Kvant, and Osa-M" and "Granit, Fort, and Osa-M" versions of Project 1144 to look at as far as I'm aware.

Speaking of Kvant, though - does anyone have any more info on that? I've only ever seen whole ship drawings with the launchers (which look like sliding hatches?) and the fire control radars (which look like ginormous search lights). And only on three drawings so far - the 1144 and 1134B drawings posted above, and one of the Atrina drawings of Project 1165.

Also, I would dearly love to know what a "Korhsun" surface to air missile is. Googling it only gives me a supersonic target version of SA-N-2 (S-75 Dvina), but there's a drawing of the 1165 with it and the launchers look *wild* - HUGE six-round circular vertical launchers, like the S-300 launchers on *all* the roids.

Project 1144 has no meaningful conventional powerplant. Saying so is like saying a car with a donut in the trunk is a 5 wheeler. It has a smaller steam plant for in-harbor maneuvering w/o turning on the reactors and to limp home in event of a reactor casualty.

Sourcing for this can be found in Apalkov's Udarniye Korabli (Morkniga, 2010) on p.79

To paraphrase, Apalkov says that the main powerplant (GEU) was 2 reactors (YaR) each hooked to a steam-turbine plant (GTZA), and that each reactor-turbine assembly developed 70,000 horsepower, for a total of 140,000. Then there was a reserve powerplant (rezervnoy energeticheskoy ustanovki) consisting of oil fired boilers which could generate 115 tons/hour of steam, enough to power the ship for 1000 nmi at 14 knots, in case the main plant failed. (highlighted section here)

Spoiler: Highlighted quote

If that wasn't clear, the article Ship Nuclear Power Plants by Rear Admiral Professor Doctor I.G. Zahkarov, Rear Admiral Professor Doctor Ya.D. Arefiev, Captain First Rank Candidate of Science N.A. Voronovich, and Captain First Rank Candidate of Science O.Yu. Leikin found here[LINK] describes the plant as follows:

Spoiler: Image with highlighted quote

...the installation with PPU (steam generator) KN-Z [the designation for the Kirov nuclear reactor, it’s unclear if it is KN-Z or KN-3, З and 3 get confused a lot] and GTZA-653 (GTZA = main turbo gear unit). This unit includes two PPU and VVR (Pressurized Water Reactor) and two GTZA with a capacity of 70,000 horsepower, each of which operates its own shaft line. The ship also has two reserve boilers with a capacity of 115 t/h each.

I hope that clears things up! This is one of the more pernicious bits of questionable western analysis about Project 1144 and it has never made any sense to me.

 

[RP1]

Project 1144 has no meaningful conventional powerplant. Saying so is like saying a car with a donut in the trunk is a 5 wheeler. It has a smaller steam plant for in-harbor maneuvering w/o turning on the reactors and to limp home in event of a reactor casualty.

Sourcing for this can be found in Apalkov's Udarniye Korabli (Morkniga, 2010) on p.79

To paraphrase, Apalkov says that the main powerplant (GEU) was 2 reactors (YaR) each hooked to a steam-turbine plant (GTZA), and that each reactor-turbine assembly developed 70,000 horsepower, for a total of 140,000. Then there was a reserve powerplant (rezervnoy energeticheskoy ustanovki) consisting of oil fired boilers which could generate 115 tons/hour of steam, enough to power the ship for 1000 nmi at 14 knots, in case the main plant failed. (highlighted section here)

Spoiler: Highlighted quote

If that wasn't clear, the article Ship Nuclear Power Plants by Rear Admiral Professor Doctor I.G. Zahkarov, Rear Admiral Professor Doctor Ya.D. Arefiev, Captain First Rank Candidate of Science N.A. Voronovich, and Captain First Rank Candidate of Science O.Yu. Leikin found here[LINK] describes the plant as follows:

Spoiler: Image with highlighted quote

I hope that clears things up! This is one of the more pernicious bits of questionable western analysis about Project 1144 and it has never made any sense to me.

Wow! OK, so it's really CONOS not CONAS? 115t/hr would be somewhere between 20-40MW at the turbine I think.

 

[whatismoo]

Wow! OK, so it's really CONOS not CONAS? 115t/hr would be somewhere between 20-40MW at the turbine I think.

According to every source I've come across! One key clue is that the Ulyanovsk class carriers shared the same plant and nobody has ever accused them of being CONAS. Apalkov has them making 31 knots on 140,000 shaft horsepower from the nuclear plant and 14 knots on the reserve boilers, which if your math is right and the reserve plant puts out around 26,000-53,000shp, that about lines up to me?

 

[insidersource]

I heard a few people today compare this to the nuclear powered Kirov class battle cruiser.

The Kirov is 28,000 ton full load. I was surprised when I noticed it use hybrid nuclear propulsion. It has two tiny nuclear reactors that put out less than 20MW of shaft power each. It can only reach 20 knots fully nuclear. It has two huge boilers running fossil fuel to allow the ship to sprint to 30 knots. It only has a range of 1,000nm at 30 knots but unlimited range at 20 knots. The normal boilers also provide redundancy.

https://en.wikipedia.org/wiki/Kirov-class_battlecruiser

 

[Dilandu]

The Kirov is 28,000 ton full load. I was surprised when I noticed it use hybrid nuclear propulsion. It has two tiny nuclear reactors that put out less than 20MW of shaft power each. It can only reach 20 knots fully nuclear. It has two huge boilers running fossil fuel to allow the ship to sprint to 30 knots. It only has a range of 1,000nm at 30 knots but unlimited range at 20 knots. The normal boilers also provide redundancy.

Sigh. No. The KN-3 reactors are fully capable of full power (each of them are 150 MW class). The oil fired boilers are only for redundancy, because Soviet admirals in 1970s were still doubting the reliability of nuclear power.

 

[Dilandu]

Nothing surprising.

Exept how many peoples believe in this nonsence, while all sources clearly stated that KN-3 reactors, used on Kirov-class ships, are of 150 MW each. No kind of "boost" is required.

 

[insidersource]

Sigh. No. The KN-3 reactors are fully capable of full power (each of them are 150 MW class). The oil fired boilers are only for redundancy, because Soviet admirals in 1970s were still doubting the reliability of nuclear power.

Sigh. No. This is a common mistake where people confuse a reactors thermal output versus it's real power output. The KN-3 reactor puts out 20 MW.

The French Suffren class submarine also has a 150 MW thermal reactor and it only has 20 MW turbine output.
https://en.wikipedia.org/wiki/Suffren-class_submarine

The Virginia class submarine has a 210MW thermal reactor and a 30MW turbine output. The ratios are the same.
https://en.wikipedia.org/wiki/Virginia-class_submarine

The old 20th century reactor designs were only 15% efficient. The best designs today are at 30% efficiency.

So each reactor in the Kirov is only putting out as much power as a single LM2500 turbine. With two reactors this 28,000 ton battlecruiser then has only half the power of an 9,000 ton Arleigh-Burke destroyer that has four LM2500.

That is why the Kirov class Wikipedia says a 20 knot top speed on nuclear power. An Arleigh-Burke can hit 20 knots with just a single LM2500 and one prop turning. Yet requires all four turbines to hit 30 knots.

At 20 knots the Kirov would only be needing around 40 MW of power. That lines up perfectly with the two 20MW reactors. The conventional boilers produce more than half of the ships max power.

 

[Dilandu]

Sigh. No. This is a common mistake where people confuse a reactors thermal output versus it's real power output. The KN-3 reactor puts out 20 MW.

Yeah, and now a bit more data; each KN-3 is actually 300 MW reactor. The data about it being 150 MW is a result of old confusion, where 300 MW was assumed to be the total POWERPLANT power (divided by two, 150 per reactor), while it was actually each reactor power (total power of the whole plant is 600 MW).

Even without knowing that - just use logic. If some kind of "boost power" was actually required, using auxilary gas turbines would be much more practical solution that oil-fired boilers. The only reason why oil-fired boilers may be considered more efficient, is if you want to have additional redunandcy.

 

[insidersource]

Yeah, and now a bit more data; each KN-3 is actually 300 MW reactor.

The KN-3 reactors came in a range from 150MW to 300MW. The Kirov had the earliest 150MW versions. 300MW was growth version for the proposed Nuclear carrier.

It is pretty easy to calculate the nuclear reactor output based on the 20 knot maximum speed and the 28,000 ton displacement. The reactors either have to be small or there is a bottleneck on the nuclear side that limits their full thermal output. The bottleneck could be for redundancy. For example the nuclear reactors might only be able to heat half of the boilers and turn half of the steam turbines. The ship is then limited to half power when running nuclear.

Even without knowing that - just use logic. If some kind of "boost power" was actually required, using auxilary gas turbines would be much more practical solution that oil-fired boilers. The only reason why oil-fired boilers may be considered more efficient, is if you want to have additional redunandcy.

No. Once your ship is using nuclear steam propulsion it is actually easier to keep using steam boilers for boost power. The boilers, steam turbines and pipework can be the same type for both the nuclear and conventional boost power.

Russia was still using boilers and steam propulsion on their destroyers that were built in the 1990's. So gas turbines didn't make sense.

In the case of the Trump class it would most likely use powerful electric motors on the props shafts like zumwalt. So like how the Kirov went all steam the Trump needs to be all electric. The nuclear reactor needs to be producing electricity instead of steam and plugged into the high voltage backbone.

With multiple microreactor designs under development they should all be in full production by 2030. I could see the Navy fitting a microreactor in every new ship. The Trump class could just have half a dozen of these shipping container sized microreactors onboard that each put out 5MW of electricity. The Navy can then add and subtract microreactors for future destroyer and cruiser designs. The Trump class is then great even if it ends up as a technology demonstrator like the Zumwalt.

 

[Dilandu]

Russia was still using boilers and steam propulsion on their destroyers that were built in the 1990's. So gas turbines didn't make sense.

Only due to industrial limitations in gas turbine production. Really, you should research history of Soviet Navy better.

 

[insidersource]

Only due to industrial limitations in gas turbine production. Really, you should research history of Soviet Navy better.

Then why did you initially suggest the Kirov class should use gas turbines for boost power?

You already knew the answer that they had limitations in gas turbines.

It seems you need to do more research. Steam boilers were the best for boost power.

 

[NMaude]

It is pretty easy to calculate the nuclear reactor output based on the 20 knot maximum speed and the 28,000 ton displacement.

Would you please elaborate on these equations?

 

[Arjen]

The KN-3 reactors came in a range from 150MW to 300MW. The Kirov had the earliest 150MW versions. 300MW was growth version for the proposed Nuclear carrier.

Combat Fleets of the World 2000-2001 by A.D. Baker III, Naval Institute Press 2000, quotes "2 KN-3 nuclear reactors (300 Mw each)".
600 MW together.

 

[Dilandu]

Then why did you initially suggest the Kirov class should use gas turbines for boost power?

Because oil-fired boilers could NOT be activated instantly, when you need the boost. The water needed to be heated first, and it took time. That's why all COSAG ships use steam for cruise and turbines for boost.

Really, you are just trying to push the myth "soviet reactors were baaad, so they needed steam boilers to maintain full power".

 

[Yellow Palace]

It is pretty easy to calculate the nuclear reactor output based on the 20 knot maximum speed and the 28,000 ton displacement. The reactors either have to be small or there is a bottleneck on the nuclear side that limits their full thermal output. The bottleneck could be for redundancy. For example the nuclear reactors might only be able to heat half of the boilers and turn half of the steam turbines. The ship is then limited to half power when running nuclear.

You're engaging in circular reasoning. If the reactors are small, then the speed is low, therefore the reactors have to be small.

The 20-knot speed claim results from reverse engineering the assumed performance from low-powered reactors, not from Western authors being handed copies of Soviet trial reports.

Really, you are just trying to push the myth "soviet reactors were baaad, so they needed steam boilers to maintain full power".

There are all sorts of things you can criticise the Soviet Navy* for, but bad reactors is not one of them.

*Criticism of all other navies and branches of service is also available.

 

[insidersource]

Really, you are just trying to push the myth "soviet reactors were baaad, so they needed steam boilers to maintain full power".

No, I'm saying the soviets perfectly sized their reactors to handle 90+% of the ships operating profile. The smaller reactors allows for more weapons.

This is exactly how all future nuclear ships should be built. Size the nuclear reactor for the average ship load with a bit of extra headroom.

So you would need at least the complement of nuclear trained crew that a carrier has.

No you won't that's the whole advantage to hybrid nuclear propulsion. If the reactor turns off due to an automated safety you do not need anyone to trouble shoot. You just leave it off for the rest of the deployment. You can't do this with a carrier as the ship be dead in the water. The hybrid nuclear setup the gas turbines generators allow the ship to maintain full capability with the reactor turned off. The Navy just needs to pay for extra fuel when they pull into port.

The reactor should be considered as a fuel saving device or a range extender.

Because oil-fired boilers could NOT be activated instantly, when you need the boost.

Large gas turbines also take 5 minutes to start up, idle and then produce full power. The oceans are vast. Plenty of Waiting for the boiler

Combat Fleets of the World 2000-2001 by A.D. Baker III, Naval Institute Press 2000, quotes "2 KN-3 nuclear reactors (300 Mw each)".
600 MW together.

"Reports differ on the power capacity of the two KN-3 reactors, with a range from 150 MW to 300 MW. These reactors would also have powered the Ulyanovsk class supercarriers, a class of ships that was canceled upon the collapse of the USSR."

https://nationalinterest.org/blog/b...ircraft-carrier-and-wants-russian-help-106636

If reactors were 300MW each the top speed wouldn't be only 20 knots. Speed versus ship power is highly exponential. A ship that uses 30 MW of power to hit 30 knots won't need 20 MW to hit 20 knots. It won't even need 10 MW to hit 20 knots.

 

[Dilandu]

If reactors were 300MW each the top speed wouldn't be only 20 knots. Speed versus ship power is highly exponential. A ship that uses 30 MW of power to hit 30 knots won't need 20 MW to hit 20 knots. It won't even need 10 MW to hit 20 knots.

The top speed is 30 knots.

 

[Dilandu]

How is the discussion about Kirov nuclear power relevant to BBG(X)?

There is a presistent myth that Kirov's reactors were unable to get it to full speed, so oil-fired boilers were installed. This myth is based on wrong assumption that 300 MW is a total power output of both reactors, while its actually just the output of one.

 

[Yellow Palace]

Please stop.

This discussion was done to death a couple of years ago on the forum here:
https://www.secretprojects.co.uk/threads/soviet-cruiser-projects.1171/page-2#post-735137

Wikipedia, for whatever reason, is repeating - without a source - an incorrect claim made in Western sources from the 1980s. Although the original claim seems to have been nuclear with oil-fired superheat, rather than an entirely independent boost steam plant.

They could set it up with with a couple MT30 turbines each driving one shaft each, and the reactor driving the other two. That should halve the nuke manning requirements vs two reactors, and machinery spaces would be fully separated vs trying to combine both steam and gas turbine on the same shaft. A single CVN reactor should have no problem pushing a ~35kt ship at 30kn even while trailing two shafts.

In the year 2026, I'd expect an IEP setup, in which case there's no need to trail any shafts. The propulsion motors just see squiggly amps (well, jaggedy amps, because electrical engineers can do clever things that way), and don't really care if they were generated by gas turbines, steam turbines, windmills, or ten million hamsters on wheels.

 

[Dilandu]

My criticism of the Red Navy is lack of training and maintenance.

Their reactors needed well trained operators, and didn't always have them. Fortunately, they did have people willing to take a lethal dose to unstick things

The general problem was, that Soviet naval reactors were designed with focusvon performance, not maintenance or reliability. They were powerful - but temperamental & hard to repair.

 

[Scott Kenny]

The general problem was, that Soviet naval reactors were designed with focusvon performance, not maintenance or reliability. They were powerful - but temperamental & hard to repair.

I'd believe that.

For better or worse, the USN went with reliability, at least after Thresher.

 

[Dilandu]

I'd believe that.

For better or worse, the USN went with reliability, at least after Thresher.

As one American ex-submariner alkegedly told Soviet ex-submariner on some meeting shortly after Cold War - "in USSR, submarine reactors were designed by multiple competing bureaus, each tried to design more and more fantastic reactor to impress the Party leadership. In USА, there were no competition, all our reactors were designed and build to an ironclad set of rules, established by Rickover, who did not tolerate any deviation. In USSR, you have a free market in terms of reactor design. And we, Americans - have Stalinism!"