Speculation and facts on future Chinese vessels

Jeff Head said:

I don't think so. Depends on the center of mass.

Take a look at an AAEGIC cruiser. They appear very top heavy, and in fact had to have some corrections early on. Now, after 30+ years at sea for some of the vessels, they are recognized as very decent sea faring and handling vessels.

Also, look at the Hobart and Daring Classes. They are very similar in appearance and ratios.

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OK first big wave is an exaggeration!

THe AGEIS Cruisers had a fine length to beam ratio it was top heavy and at the margins of the underlying hull design the move to VLS alleviated some of the top weight issues by dispensing with the launchers, it didn't have a solid mast and a 10m draught, the follow on Burke's hull was fundamental redesigned with less length but greater beam to improve sea worthiness, but it wasn't perfectly executed and some of the burkes suffered structural issues in rough waters which had to be rectified.

Can't say anything about Hobarts they're not in the water yet as they've had build problems but the Álvaro de Bazán class from which they are derived doesn't have a solid mast either.

The Darings have a huge beam to compensate for it's massive solid mast the length beam ratio of a Daring is more akin to a WW2 era battleship than a modern destroyer.

It might be an optical illusion but that puppy looks like it's long and fine without much draught not something you'd stick a tall solid mast on which will in effect acts as a sail,

But hey they all look the same!

hkbc said:

OK first big wave is an exaggeration!

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Hehehe...I know, was just answering back.

hkbc said:

The AGEIS Cruisers had a fine length to beam ratio it was top heavy and at the margins of the underlying hull design the move to VLS alleviated some of the top weight issues by dispensing with the launchers, it didn't have a solid mast and a 10m draught, the follow on Burke's hull was fundamental redesigned with less length but greater beam to improve sea worthiness, but it wasn't perfectly executed and some of the burkes suffered structural issues in rough waters which had to be rectified.

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Yes, but now, all in all, both are considered to be very sea worthy and the AEGIS cruisers are now approaching (in the next few years for the erralier ones) the end of their service life.

hkbc said:

The Darings have a huge beam to compensate for it's massive solid mast the length beam ratio of a Daring is more akin to a WW2 era battleship than a modern destroyer.

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Well, I do not know if I would go that far.

hkbc said:

It might be an optical illusion but that puppy looks like it's long and fine without much draught not something you'd stick a tall solid mast on which will in effect acts as a sail...

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Well, I am sure it is an integrated mast and covered over, but not necessarily solid at all. A lot dpends on the wieght of what is underneath the skin, which is probably some kind of compsite.

For reference, here are the various dimensions:

Daring:
Length: 495 ft (151m)
Beam: 65 ft (20m)
Draft: 16 ft (5m)

Burke IIa
Length: 513 ft (155m)
Beam: 66 ft (20m)
Draft: 31 ft (9m)

Tico
Length: 567 ft (173m)
Beam: 55 ft (17m)
Draft: 33 ft (10m)

Zumwalt
Length: 600 ft
Beam: 80 ft
Draft: 28 ft

Lanzhou (Type 052C)
Length: 505 ft (154m)
Beam: 56 ft (17m)
Draft: 20 ft (6m)

Hobart
Length: 483 ft
Beam: 61 ft
Draft: 18 ft

Bazan (F-100)
Length: 482 ft
Beam: 61 ft
Draft: 15 ft

I will put in a bit of speculations myself. I think the next Chinese destroyer will have the following characteristics:

• Integrated Electric Propulsion
• Bigger beam-to-length ratio to accommodate for bigger superstructure
• Bigger displacement
• Same mast as the one used on recent frigates and destroyers

Currently, what limits the displacement of Chinese naval vessels is propulsion. The CODOG arrangement currently being used by China is at its limit, and at the same time a reliable CODAG arrangement appears to be beyond Chinese manufacturing capability. The need for COGAG to combine power from two sets of engines would also pose a similar problem as CODAG. However, I think what makes COGAG out of the question is Chinese Navy's apparent preference to use diesel engines for cruise for fuel economy reasons.

If China has to choose between the aforementioned propulsion arrangements, I believe they would go for CODAG due to fuel economy reason. However, with experience in building conventional submarines and other national projects related to electricity, I think China would play its strength by removing the need of gearboxes with Integrated Electric Propulsion. I also believe this to be the primary reason why China has still not launched its next generation destroyer.

With the propulsion problem solved, China would no longer require small beam-to-length ratio for speed. The ratio would naturally get bigger as a result, allowing the naval architects more freedom in arrangement of the upper structures. Of course, this would automatically result in bigger displacement.

As for my last speculation, I think China has standardized the mast on its ships. Similar masts are being used from 056 all the way up to the Liaoning carrier. I therefore do not think China would go for an integrated mast.

Jeff Head said:

Hehehe...I know, was just answering back.

Yes, but now, all in all, both are considered to be very sea worthy and the AEGIS cruisers are now approaching (in the next few years for the erralier ones) the end of their service life.

Well, I do not know if I would go that far.

Well, I am sure it is an integrated mast and covered over, but not necessarily solid at all. A lot dpends on the wieght of what is underneath the skin, which is probably some kind of compsite.

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You don't seem to have a real understanding of the Type-45 and your surety is totally misplaced

It's not an integrated mast nor is it solid there's 3 radars on a Type 45 the S1850 a rotating volume air search radar at the back behind the funnel, not usually a great place to put a radar but the WR-21 gas turbines in the Type 45 recycles heat so doesn't interfere as much as conventional engines, on top of the main mast is the SAMPSON in the spherical radar dome which is a rotating 2 faced back to back AESA multifunction radar, finally a navigation radar mounted externally half way up the foremast, the other domes are SatCom equipment.

The air draught of the ship is 39m all that height in the mast is to allow the SAMPSON to see further over the nominal horizon and track low flying planes and missiles to give better reaction times against supersonic SSMs, because the SAMPSON is an AESA and rotates the mast needs to house the mechanicals, cabling etc as opposed to just hollow wave guides. So there's weight right at the top of the mast hence the need for the broad beam hull maximise stability and counteract roll.

Almost all indigenous Euro anti air frigates/destroyers such as De Zeven Provinciën, Iver Huitfeldt, Sachsen, Horizon classes follows the mast mounted multifunction AESA/PESA with a SMART-L derived volume search radar design pattern.
The design is a complete departure from mounting large flat PESA panels on the superstructure as in the Burkes and Ticos, Type 052C etc.

The Royal Navy has gone to extremes with placing it's multifunction radar so high above the waterline and not unsurprisingly has/needs the broadest beam hull.

Jeff Head said:

For reference, here are the various dimensions:

Daring:
Length: 495 ft (151m)
Beam: 65 ft (20m)
Draft: 16 ft (5m)

Burke IIa
Length: 513 ft (155m)
Beam: 66 ft (20m)
Draft: 31 ft (9m)

Tico
Length: 567 ft (173m)
Beam: 55 ft (17m)
Draft: 33 ft (10m)

Zumwalt
Length: 600 ft
Beam: 80 ft
Draft: 28 ft

Lanzhou (Type 052C)
Length: 505 ft (154m)
Beam: 56 ft (17m)
Draft: 20 ft (6m)

Hobart
Length: 483 ft
Beam: 61 ft
Draft: 18 ft

Bazan (F-100)
Length: 482 ft
Beam: 61 ft
Draft: 15 ft

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Not sure where you're getting your numbers from but hope your not doing a Karl Rove on me the dimensions of the Daring are

Length 152m (498.7 ft)
Beam 21.2m (69.5 ft)
Draught 5.3m (17.3 ft)

(length Beam ration of 7.17:1)

as referenced in (that's the official UK government website for the Royal Navy)

If you're using the figures you listed on your site, maybe you should change them to the correct values.

For reference a King George V (1939) Class battleship was 745 ft by 103 ft (length Beam ratio of 7.23:1)

Finally, the excessive draughts of most of the other vessels listed is down to the sonar dome budge not the hull, the Type 45 hull form is not ideal for ASW work so the Type-26 frigates will use a different hull form.

Engineer said:

I will put in a bit of speculations myself. I think the next Chinese destroyer will have the following characteristics:

• Integrated Electric Propulsion
• Bigger beam-to-length ratio to accommodate for bigger superstructure
• Bigger displacement
• Same mast as the one used on recent frigates and destroyers

Currently, what limits the displacement of Chinese naval vessels is propulsion. The CODOG arrangement currently being used by China is at its limit, and at the same time a reliable CODAG arrangement appears to be beyond Chinese manufacturing capability. The need for COGAG to combine power from two sets of engines would also pose a similar problem as CODAG. However, I think what makes COGAG out of the question is Chinese Navy's apparent preference to use diesel engines for cruise for fuel economy reasons.

If China has to choose between the aforementioned propulsion arrangements, I believe they would go for CODAG due to fuel economy reason. However, with experience in building conventional submarines and other national projects related to electricity, I think China would play its strength by removing the need of gearboxes with Integrated Electric Propulsion. I also believe this to be the primary reason why China has still not launched its next generation destroyer.

With the propulsion problem solved, China would no longer require small beam-to-length ratio for speed. The ratio would naturally get bigger as a result, allowing the naval architects more freedom in arrangement of the upper structures. Of course, this would automatically result in bigger displacement.

As for my last speculation, I think China has standardized the mast on its ships. Similar masts are being used from 056 all the way up to the Liaoning carrier. I therefore do not think China would go for an integrated mast.

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IEP isn't that straightforward you need big powerful electric drive motors even the yanks crashed and burned and had to revert to using Anglo French motors in the Zumwalts (they liked them so much GE bought a 90% stake in the company last year, so I guess we'll have to call them American now!) so moving away from a COGAG/CODAG to IEP simply shifts the problem from a mechanical engineering one to a electrical engineering one. Instead of high end gearbox design it becomes a high end induction motor design exercise.

Engineer said:

As for my last speculation, I think China has standardized the mast on its ships. Similar masts are being used from 056 all the way up to the Liaoning carrier. I therefore do not think China would go for an integrated mast.

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Well masts on all recent surface combatants, including CV16 all seem standardized to a degree, but that's this generation. Already we see a little bit of departure with 052D's mast, and I expect the next generation of ships to feature a new standardized mast configuration.

As for propulsion, I think it was mentioned in the 052 thread that 4 QC-280s could quite comfortably power a cruiser sized ship.

That CG looks bit unreal I doubt that is a representation of future cruiser for PLAN

Engineer said:

Currently, what limits the displacement of Chinese naval vessels is propulsion. The CODOG arrangement currently being used by China is at its limit, and at the same time a reliable CODAG arrangement appears to be beyond Chinese manufacturing capability. The need for COGAG to combine power from two sets of engines would also pose a similar problem as CODAG. However, I think what makes COGAG out of the question is Chinese Navy's apparent preference to use diesel engines for cruise for fuel economy reasons.

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I don't think PLAN warship displacement is limited by propulsion at all. Now that it can manufacture the QC280, there is absolutely no limit to what destroyer designs can be imagined. And why is CODAG is "beyond Chinese manufacturing capability". Please quote a source. We actually don't even know whether any of the current PLAN ships in service are CODOG or CODAG. Even if there are not, there are good reasons to have CODOG instead of CODAG, namely the bulk of the gearing needed for CODAG along with greater cost and maintenance requirements. And if your ship doesn't need the combination of diesel and GT, there is no reason to use it at all.

I also don't know why you think COGAG is "out of the question". It is certainly not out of the question. I would bet in fact that it is very much in the question, especially if PLAN decides on 10,000+ sized vessels in the future. And it's not like it will be hard to know; you will be able to tell a ship is COGAG by the number of large funnels coming out of the deck. CODAG's will not be able to fill this role, given how wimpy a diesel's output is compared to GT's.

Engineer said:

If China has to choose between the aforementioned propulsion arrangements, I believe they would go for CODAG due to fuel economy reason. However, with experience in building conventional submarines and other national projects related to electricity, I think China would play its strength by removing the need of gearboxes with Integrated Electric Propulsion. I also believe this to be the primary reason why China has still not launched its next generation destroyer.

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Why do you think CODAG gearing is somehow so complicated that China could design and build an electric drive before it could build CODAG gearing? CODAG tranmission are more complicated than CODOG sure, but that doesn't mean it's actually so complicated that Chinese naval designers couldn't build them.

Mysterre said:

I don't think PLAN warship displacement is limited by propulsion at all. Now that it can manufacture the QC280, there is absolutely no limit to what destroyer designs can be imagined. And why is CODAG is "beyond Chinese manufacturing capability". Please quote a source. We actually don't even know whether any of the current PLAN ships in service are CODOG or CODAG. Even if there are not, there are good reasons to have CODOG instead of CODAG, namely the bulk of the gearing needed for CODAG along with greater cost and maintenance requirements. And if your ship doesn't need the combination of diesel and GT, there is no reason to use it at all.

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Prime reason for not using COGAG is lack of flexibility and fuel economy here's an extract from a piece on the Arleigh Burke Class

During underway operations under 15 knots, in low-threat areas, 2 engines are typically on line: a GTM with a trail shaft, and a smaller GTG for basic power to the ship, navigation radars etc. Speed changes up to 15-18 knots are controlled by varying propeller pitch, and are independent of the LM2500 GTM.

If a current DDG-51 destroyer or CG-47 cruiser needs to increase speed to 18-24 knots, a 2nd LM2500 GTM is put online. Speeds of 24-28 knots require 3 GTMs online, and are often used by the “plane guard” cruiser or destroyer, on station 3 nautical miles behind the aircraft carrier during launch or recovery.

The plane guard refuels every 3 days to maintain 75% fuel, while the rest of the escorting cruisers and destroyers refuel every 7-10 days.

Full piece here

Mysterre said:

I also don't know why you think COGAG is "out of the question". It is certainly not out of the question. I would bet in fact that it is very much in the question, especially if PLAN decides on 10,000+ sized vessels in the future. And it's not like it will be hard to know; you will be able to tell a ship is COGAG by the number of large funnels coming out of the deck. CODAG's will not be able to fill this role, given how wimpy a diesel's output is compared to GT's.


Why do you think CODAG gearing is somehow so complicated that China could design and build an electric drive before it could build CODAG gearing? CODAG tranmission are more complicated than CODOG sure, but that doesn't mean it's actually so complicated that Chinese naval designers couldn't build them.

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Diesels aren't "wimpy" the Wärtsilä 16V 46C-CRs in the Queen Mary 2 spits out 16.8MW (with 4 of those you can have any ship size up to a small carrier) they just don't provide as much power per unit volume as GTs, their primary disadvantages compared to GTs are they can't be maintained by replacement, they don't provide the power on demand acceleration that warships typically need and for ASW ops they have higher noise and vibration levels so need more dampening. The primary advantage is that they're very economical across a full spectrum of operating environments. This is why CODOG exists, run on diesels for cruise switch to GTs for sprints.

CODAG gearing is complicated simply because GT drives rotates at orders of magnitude more than even the highest speed marine diesels each engine type will need it's own reduction gearing and the revs will need to be matched when drive is applied to the shaft. It's simpler just to run the diesels and GTs on separate shafts and take the hydrodynamic hit of trailing shafts or run a CODOG arrangement. It's not a matter of whether the Chinese or any other Naval designer can build them it's whether what they build is useful.

With regard to electric propulsion, it has been around for 100 years (the first US flat top, USS Langley, used turbo electric propulsion) and was used to move large ships during WW2 e.g. USS Lexington (CV3). The trick is getting an efficient electric propulsion system, that doesn't take up acres of space and is fuel efficient, since the double conversion of mechanical energy to electricity and back means more energy gets lost than with simple mechanical transmission.

hkbc said:

Prime reason for not using COGAG is lack of flexibility and fuel economy here's an extract from a piece on the Arleigh Burke Class

During underway operations under 15 knots, in low-threat areas, 2 engines are typically on line: a GTM with a trail shaft, and a smaller GTG for basic power to the ship, navigation radars etc. Speed changes up to 15-18 knots are controlled by varying propeller pitch, and are independent of the LM2500 GTM.

If a current DDG-51 destroyer or CG-47 cruiser needs to increase speed to 18-24 knots, a 2nd LM2500 GTM is put online. Speeds of 24-28 knots require 3 GTMs online, and are often used by the “plane guard” cruiser or destroyer, on station 3 nautical miles behind the aircraft carrier during launch or recovery.

The plane guard refuels every 3 days to maintain 75% fuel, while the rest of the escorting cruisers and destroyers refuel every 7-10 days.

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I don't see how any of what you posted indicates lack of flexibility. Fuel economy is not even an argument. By nature GT is less fuel efficient, but I have already mentioned that. On the other hand, you have a limited space and a certain tonnage and speed requirement. If two diesels and two GT's cannot satisfy this requirement in the space available, you build a ship using COGAG, despite the cost in fuel efficiency. Navies all over the world use COGAG in their destroyers. So where's the fire?

hkbc said:

Diesels aren't "wimpy" the Wärtsilä 16V 46C-CRs in the Queen Mary 2 spits out 16.8MW (with 4 of those you can have any ship size up to a small carrier) they just don't provide as much power per unit volume as GTs, their primary disadvantages compared to GTs are they can't be maintained by replacement, they don't provide the power on demand acceleration that warships typically need and for ASW ops they have higher noise and vibration levels so need more dampening. The primary advantage is that they're very economical across a full spectrum of operating environments. This is why CODOG exists, run on diesels for cruise switch to GTs for sprints.

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The day you can point out a destroyer to me that is the size of the Queen Mary 2 is the day its Warsila diesels will have any relevance in a discussion about destroyers. Until then it is meaningless to compare the diesels used in a 149,000 ton ship to the ones used on a 7,000 ton ship. The 052C uses diesels that put out 5MW. Its GT's put out 28MW. So as I said, the diesels are in fact wimpy compared to the GT's.

hkbc said:

CODAG gearing is complicated simply because GT drives rotates at orders of magnitude more than even the highest speed marine diesels each engine type will need it's own reduction gearing and the revs will need to be matched when drive is applied to the shaft. It's simpler just to run the diesels and GTs on separate shafts and take the hydrodynamic hit of trailing shafts or run a CODOG arrangement. It's not a matter of whether the Chinese or any other Naval designer can build them it's whether what they build is useful.

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Again, the argument has been about whether Chinese shipbuilding industry is capable of building ships with engines using CODAG arrangements, not whether you personally think CODAG is "complicated". Can you provide evidence either way?