052C/052D Class Destroyers

A

antiterror13

Brigadier
Cloud_Nine_ said:
Probably a mix of cost and lack of necessity. The whole point, or at least 80% of adopting an IPS or IPES system was to enable high energy weapons like railguns and directed energy and such; both of which have foggy prospects at best. Space is probably also an issue for PLAN who needs to min-max on workhorse DDGs for the future. IPES needs energy storage and more space than CODLAG.
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IEPS needs energy storage? very news to me ... how ?
 
I

Iron Man

Major
Registered Member
Cloud_Nine_ said:
The Daring class is one of if not the single worst example of IEP warships. Granted, a lot of it comes down to the unreliability of the WR-21 in tropical conditions and a very badly designed grid which is now being somewhat alleviated with the PIP upgrade.

Still, despite being an IEP ship, Darings are notoriously noisy, negating any sort of advantage in anti-submarine warfare. The dilemma of these types of ships is what you want the IEP system to do. If all you do is just channel power generated from your engines to the propellors through electric motors, that's not a very distinct advantage at all. By having electric motors as the middle man, not only does it take up more weight and space, but a not negligible bit of power gets lost in the process. Not to mention the added cost compared to a traditional and very mature mechanical system.
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You have not shown that the Daring's alleged noisiness is due to its IEP.

Also, note that the WR-21 is a 21.5MW GT while the diesels are each 2MW for a total installed power of 47MW driving an 8,500t ship to 32+ knots, not even including what the rest of the ship needs in power, such as for its SAMPSON AESAs. Meanwhile the 052D uses 2 "QC-280" GTs generating "28"MW (probably more like 25MW in the real world) for a total of 56MW driving a 7,500t ship to 30 knots (if that). Clearly a mechanical transmission is far less efficient than an electric motor. This seems to me like a 052D converted from CODOG to IEP may not even need one of its two GTs with the increased efficiency and the addition of the diesels into the mix, and I suspect that if a "055A" went full IEP it could probably ditch an entire pair of GTs. And let's not even mention the fact that your own graphic that you posted is selling you out on this point LOL.

Meanwhile since the 052D is CODOG, the diesels are dead weight and space during high speed runs, while the opposite is true during low speed transits, since neither the pair of diesels nor the pair of GTs are connected to the grid and cannot provide power for anything when not in use. So there's dead weight and space no matter how you run the ship. Even with a CODLAG arrangement the GTs are dead weight and space except during high speed runs since only the diesels are connected to the grid. Only once you also plug the GTs into the grid do you get maximum benefit and space/weight utilization all the time every time. But then that's literally what IEP is.

Cloud_Nine_ said:
Fuel efficiency and endurance are relatively not that noticeable problems for PLAN DDGs since 052Ds are CODOG ships and 055s have a cross-connect gearbox, allowing them to drive twin props with just one GT. High energy weapon is just another area of hopeful systems that doesn't actually translate that well into actual capabilities. Railguns are pretty much a bust atm and directed energy systems don't eat up that much power anyway. Whatever extra power needed can be provided by simply having more generators as 055 does.
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So little faith you have. That coil gun sitting on the test 072III is a far more mature system than the American rail gun given one's been testing on an actual platform and the other is for all intents and purposes shut down as a program. As for DEW, it depends on what you're talking about. Lasers maybe not, but I suspect for HPMs they will suck up alot of power given they are essentially AESA arrays turned up to high. US and PLAN both going for more power capability in new surface combatant platforms but you're literally advocating the opposite LOL
 
Cloud_Nine_

Cloud_Nine_

Junior Member
Registered Member
Iron Man said:
You have not shown that the Daring's alleged noisiness is due to its IEP.

Also, note that the WR-21 is a 21.5MW GT while the diesels are each 2MW for a total installed power of 47MW driving an 8,500t ship to 32+ knots, not even including what the rest of the ship needs in power, such as for its SAMPSON AESAs. Meanwhile the 052D uses 2 "QC-280" GTs generating "28"MW (probably more like 25MW in the real world) for a total of 56MW driving a 7,500t ship to 30 knots (if that). Clearly a mechanical transmission is far less efficient than an electric motor. This seems to me like a 052D converted from CODOG to IEP may not even need one of its two GTs with the increased efficiency and the addition of the diesels into the mix, and I suspect that if a "055A" went full IEP it could probably ditch an entire pair of GTs. And let's not even mention the fact that your own graphic that you posted is selling you out on this point LOL.

Meanwhile since the 052D is CODOG, the diesels are dead weight and space during high speed runs, while the opposite is true during low speed transits, since neither the pair of diesels nor the pair of GTs are connected to the grid and cannot provide power for anything when not in use. So there's dead weight and space no matter how you run the ship. Even with a CODLAG arrangement the GTs are dead weight and space except during high speed runs since only the diesels are connected to the grid. Only once you also plug the GTs into the grid do you get maximum benefit and space/weight utilization all the time every time. But then that's literally what IEP is.


So little faith you have. That coil gun sitting on the test 072III is a far more mature system than the American rail gun given one's been testing on an actual platform and the other is for all intents and purposes shut down as a program. As for DEW, it depends on what you're talking about. Lasers maybe not, but I suspect for HPMs they will suck up alot of power given they are essentially AESA arrays turned up to high. US and PLAN both going for more power capability in new surface combatant platforms but you're literally advocating the opposite LOL
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For one, that's exactly my point concerning the quietness part. Noise reduction is primarily an engineering and quality control problem, thus there isn't an incentive to go for IPS or IEP purely for being quiet.

QC280 is the Chinese version of the UGT-25000 built by AECC, who was commissioned by CSSC to produce the now domestic version GT-25000 to compete. To clarify, all UGT-25000-derived marine GT installed on PLAN warships are CSSC's GT-25000, now renamed to CGT-25M. I am not sure exactly how much power it outputs but by the name, it's safe to say it's 25MW. WR-21, by RR's fact sheet, is also a 25MW GT under ISO conditions. Propulsion, however, is provided by two 20MW AIM motors. QQ20250212-172417@2x.png
Ofc to your point, Type 45 is able to achieve relatively high speeds with just 40MW of propulsion. I think it probably has more to do with 052Ds having a worse hull form for high speed than anything else. I mean like, the CGT-25M itself is not as power & space efficient as an MT-30 or CGT-40M (apparently CGT-40M takes up pretty much the same amount of space as CGT-25M does) so anything CSSC can provide now is probably automatically better. Certainly not a fan of CODOG.

I am relatively on the fence about dubious capabilities not in service yet so I will happily receive criticism on that front. I personally think shooting for the best is better but my previous response is more so thinking in the shoes of CODLAG vs IPS.
 
I

Iron Man

Major
Registered Member
Cloud_Nine_ said:
For one, that's exactly my point concerning the quietness part. Noise reduction is primarily an engineering and quality control problem, thus there isn't an incentive to go for IPS or IEP purely for being quiet.
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I don't think anyone is saying one of IEP's pros is being quiet. Nonetheless, you have not shown that it is particularly noisy compared to other propulsion setups.

Cloud_Nine_ said:
Ofc to your point, Type 45 is able to achieve relatively high speeds with just 40MW of propulsion. I think it probably has more to do with 052Ds having a worse hull form for high speed than anything else. I mean like, the CGT-25M itself is not as power & space efficient as an MT-30 or CGT-40M (apparently CGT-40M takes up pretty much the same amount of space as CGT-25M does) so anything CSSC can provide now is probably automatically better. Certainly not a fan of CODOG.
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All other things being equal, a higher length to beam ratio is better for speed. For the Daring it's 7.19, while for the 052D it's 8.94.

As for CODOG (and COGOG), it's the worst of both worlds as far as space and efficiency is concerned. And more to the point, anything less than IEP is less space and weight efficient comparatively. Back to my original statement, there isn't anything about the Type 45 that makes it inherently inferior just because it has an IEP setup; the execution of the Type 45 is clearly lacking but AFAIK it's not the IEP itself that has been at fault. Clearly surface combatants can use IEP, and IEP can make use of less power generating sources (GTs/diesels) more efficiently than anything else. It's more a matter of cost and complexity than anything else. For smaller surface combatants like FFGs and DDGs, CODLAG is perfectly suitable if cost is an issue. Meanwhile for larger ships like 055 and follow-ons that may play host to more exotic weaponry, IEP makes perfect sense. I suspect the tradeoff in the space for losing a pair of GTs and the transmission and adding electric motors for the props, generators for the remaining GTs, and +/- batteries may actually favor the latter in terms of weight and space. A hypothetical 055A with IEP could maybe even add an extra pair of UVLS on the back end as a result.
 
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