Sovremenny Question

[CJackson]

Why did the Soviets construct Sovremenny class vessels with steam turbines instead of COGAG gas turbines?

[orionhawk]

Well, since no one else has responded, I guess the Navy Snipe can take a shot. I suspect they just didn't have good/reliable gas turbine technology available at the time, at least when they designed/built the class lead...

Gas Turbines require high-precision machining of (relatively) light alloys, the ability to make massive amounts of light-oil fuel, again with fairly high quality control, and are generally at least partly computer-controlled. They also burn through that fuel quite quickly, which can complicate supply for a Navy that spends a lot of time at sea. The USN handles this by running everything we possibly can, from all of our aircraft, to every GT-powered ship (and at least some of the boilers), to the CB's humvees, on JP-5. That way we only have to carry one petroleum-based fuel.

Steam turbines work. Hell, that's how Nimitz-class nuke carriers convert reactor heat into shafts and screws turning.

Maybe if we have any Russian Navy snipe-types lurking, they could join in and answer better than I can.

[Sauragnmon]

Considering the Russians have at least the basics of gas turbine design at hand, in the T-80, it's more likely that they wished to use steam turbines on the Sovremenny more towards ease of maintenance - they operate plenty of steam turbines, no having to retrain people to maintain them, and for efficiency - as you aptly pointed out, gas turbines drink fuel like a career alcoholic drinks cheap beer.

The Russians have had their own time with experimental engine processes - the Alfa class, one of the few, if only, naval designs to use a Liquid Metal cooled Fast Reactor. Probably, after the maintenance issues they had with those, they'd prefer to opt for something solid and reliable that doesn't require a lot of work, is a proven design, and can hold up for a long time, to run what would be and still is their mainstay heavy destroyer.

You don't run the core of operations on something that's got a lot of if's with it, it just doesn't make tactical sense, especially to the Russian doctrine of thinking. This same doctrine of thinking is why the Slava class exists - "we don't know if the Granit missile will pay off, so we'll operate a class beside the Kirov that uses the older Bazalt." Granted, this is the same navy that for some crazy reason still hasn't finished the weapons loadout on the Kirov class cruisers... there are still launchers missing, even on the Pyotr Velikiy.

[orionhawk]

very good post. that was what I fugured, and was trying to say.


the Alfa class, one of the few, if only, naval designs to use a Liquid Metal cooled Fast Reactor.
from Wiki:
The Soviet (http://en.wikipedia.org/wiki/Soviet_Union) Alfa class submarine (http://en.wikipedia.org/wiki/Alfa_class_submarine) uses a lead cooled reactor, and both the Soviet and US navies had earlier constructed prototype attack submarines using LMFR power units.
USS Seawolf (SSN-575) (http://en.wikipedia.org/wiki/USS_Seawolf_%28SSN-575%29) was the second nuclear submarine, and the only U.S. submarine to have a sodium-cooled nuclear power plant. It was commissioned in 1957 (http://en.wikipedia.org/wiki/1957), but it had leaks in its superheaters (http://en.wikipedia.org/wiki/Superheater), which were bypassed. In order to standardize the reactors in the fleet, the submarine's sodium-cooled reactor was removed starting in 1958 (http://en.wikipedia.org/wiki/1958) and replaced with a pressurized water reactor (http://en.wikipedia.org/wiki/Pressurized_water_reactor).

[CJackson]

Good posts orionhawk and Sauragnmon.

[Sauragnmon]

Ultimately, Orionhawk, you simply invalidated my "if only" part in that statement. I lean more of my study towards Russian equipment, thus will not purport to know absolutely everything American. Though I dare say, I would consider it quite a risky thought to equip a reactor in a Submarine, a ship bound to be surrounded on all sides by water, with a reactor cooled by either the more common Sodium-Bismuth Eutectic Mixture (which has radiation problems over long use) or pure Liquid Sodium, as I don't know if the NaBi Eutectic will still have the same reaction, but I could just imagine the spectacular reaction should a sodium reactor meet water, let alone a simple coolant leak. Sodium in raw air burns, touch water it explodes. Lead's a significantly safer choice - while it would also to a degree explode due to temperature difference of core heat vs ocean water, it's not only a relatively inert metal, but at the same time a prime shielding agent. Unfortunately, you have to keep a LMFR hot when the reactor's shut down, or else you wind up with an inert brick of metal, not a reactor. The upside is their low weight vs PWR's, lending to the Alfa's good speed.

But I digress. End of the day, Sovremenny design was most likely for ease of maintenance, solid design, ad fuel efficiency. This is why the T-80 is in small numbers, in special assignment units, and everything else runs on a diesel engine. They have their merits, but they're damn expensive to run, maintain, and produce. Nuff said.

[wilhelm]

Well, since no one else has responded, I guess the Navy Snipe can take a shot. I suspect they just didn't have good/reliable gas turbine technology available at the time, at least when they designed/built the class lead...

Gas Turbines require high-precision machining of (relatively) light alloys, the ability to make massive amounts of light-oil fuel, again with fairly high quality control, and are generally at least partly computer-controlled. They also burn through that fuel quite quickly, which can complicate supply for a Navy that spends a lot of time at sea. The USN handles this by running everything we possibly can, from all of our aircraft, to every GT-powered ship (and at least some of the boilers), to the CB's humvees, on JP-5. That way we only have to carry one petroleum-based fuel.

Steam turbines work. Hell, that's how Nimitz-class nuke carriers convert reactor heat into shafts and screws turning.

Maybe if we have any Russian Navy snipe-types lurking, they could join in and answer better than I can.

The Soviets in fact had their first class of gas turbine ships a full ten years before the USN. This was the Kashin class which was innovative in its propulsion as the first naval class of surface combatants in the world with an all gas turbine propulsion.

Generally speaking steam turbines are more efficient at slow speed and gas turbines more efficient at high speed.

[orionhawk]

sorry if I offended anyone. I was purely wild-assed-guessing, as no one else had responded.:oops:

[Sauragnmon]

I personally wasn't offended, not in the least bit - this is either study and statement, or speculation, and that's all well and fine, as I say it.

[wilhelm]

sorry if I offended anyone. I was purely wild-assed-guessing, as no one else had responded.:oops:

Hey man, don't worry...... I was not offended in the slightest as I have no direct link to the Kashin class and have never been to Russia.:)

I come on to MP.net as there are many interesting threads that I learn many interesting things from. You'll most likely remember the Kashin class now and come over like some sort of genius when you correct somebody on this topic next time.p-)p-)

No doubt next week I'll be learning something from you......:)

[Sauragnmon]

Here's a fun fact for you to catch people off guard with, or a couple, regarding the Kirov Class:

A) There is only One ship of the class that actually has SA-N-9/Kinzhal missile launchers, and this is the Pyotr Velikiy, even then, this is only on the aft deck. They were Planned to have them, but there was a shortage, from building the Udaloy class, that resulted in the ships not having them installed. To verify, notice on the forward radar collection, a lack of Cross Swords radar set - this would be found, for the forward set, on the pedestal between the two Hot Flash radar domes, or in the case of Frunze, between the Base Tilt radars. The Pyotr has the aft deck launchers, as it has the Cross Swords radar sitting on the aft superstructure position, aft of the Top Dome radar.

B) It is actually true, however you might doubt, that the forward position actually carries 96 ready-to-fire S-300F missiles on the Kirov Class. This is accomplished by under-deck rotary systems, as seen on some of the earlier classes. This is why there are twelve hatches but 96 missiles stored. Unfortunately, the launcher design makes them a pain to reload as well.