055 DDG Large Destroyer Thread

[Blitzo]

First the Requirements for a ASW chopper and those of a combat transport.
Z20 is optimized as a combat transport Chopper. The placement of the Landing gear particularly the rear wheel the number of Rotor blades. these features are optimized for rigidity and survive ability under ground fire.
It's rear wheel's placement suggests it's meant to act as a anchor allowing the crew in a emergency to stick it into the ground and slam the weight down on the forward wheels which are shock absorbers. In order to do that the Rear wheel has to be very very structurally sound.

A ASW chopper is rarely meant to take ground fire, particularly those assigned to a DDG or Cruiser. It has to fit in a compact space. To do that the tail needs to be fordable. that's contradictory, Z15 however offers a alternitive as it uses a conventional tricycle. this is better suited to a ship, and it means the tail is just a tail only meant to support the rear rotor. next Z20 follows the same sleek hull form of the blackhawk. This means a ASW Z20 would need to be reconfigured with structural member to support emergency floats and torpedos, Z15 already has the start of these. Look I am just voicing my opinion her just as You are But I think The Z15 is better suited to the Naval mission set and Vip then Z20. Z20 Seems a good choice for PLA ground forces and Air Forces.

Naval Z-20 can be modified for the rear wheel to be placed forward like the SH-60, that is not a problem. At least, it is better to address that issue rather than go for an inferior product like Z-15.

Naval Z-20 would of course be modified like how UH-60 was for SH-60. That is expected. A Naval Z-15 would also be modified similarly. The big question is whether it makes sense to navalize Z-15 in the first place, when a navalized Z-20 would be superior in almost all domains.

And it might be easier to navalize Z-20 as well,, if only on the basis that USN has done it already, so CHAIC would have an idea of where to start, versus trying to navalize Z-15, which is a competely unknown quantity.

 

[Solaris]

Being able to physically carry a chopper of that size doesn't mean they can safely recover and launch it, which is dependent on helipad. Furthermore, as I already said in my previous post, the much greater height of a 13 ton helicopter versus a 10 ton helicopter also has big implications for the final height of the aft structure which houses the helipad.

Having the hangar space for two ten ton helos does not mean one can field a 13 ton helicopter, because of both the height of the hangar, and also the size of the helipad. I clarify the ship size question at the end of this post.

I'm not sure a 1.5m height difference (Super Frelon vs SH-60) for the hangars is of any real significance, whether on a 4,000 ton ship or a 13,000 ton ship. You'd have to prove that one to me. The helipad can be made to the needed specifications IMO also without much ado; as far as this goes the only important measure IMO is the bow-stern length of the helipad, regarding which a 1.275m (2.55m / 2) difference is also of little significance.

I think we are getting into semantics of what "size" means.
For me, not having the "large enough ships" means having large enough hulls which may affordably and practically field large enough hangars and helipads. That affordability and practicality is of course determined by hull size.

So I think we both technically agree on the size issue. I suppose I should have added on the "worth it or not" part, but I thought that was pretty self explanatory. After all, almost all ships can accommodate any piece of subsystem with enough modification, and it is size that determines whether the modification or design choice is worth it or not.

Yes. In the end we will just have to wait for the photos and for more information to come out of the PLAN.

 

[Blitzo]

I'm not sure a 1.5m height difference (Super Frelon vs SH-60) for the hangars is of any real significance, whether on a 4,000 ton ship or a 13,000 ton ship. You'd have to prove that one to me. The helipad can be made to the needed specifications IMO also without much ado; as far as this goes the only important measure IMO is the bow-stern length of the helipad, regarding which a 1.275m (2.55m / 2) difference is also of little significance.

I definitely lack the expertise to prove that (though I understand that I have the onus to back up my claim), in which case I will concede that ship size may not be important, or at least not as important in determining whether a ship fields a larger or a smaller helicopter compared to other reasons that we've already discussed.

I still think however, there is a relationship between ship hull size and the ease to which they can be designed with facilities to accommodate a larger helicopter, but it may not be a very steep line.

Yes. In the end we will just have to wait for the photos and for more information to come out of the PLAN.

Right

 

[delft]

and there is still the Z15, of which the PRC now has the rights to production Or perhaps the PLAN would decide to continue with Kamov choppers. The Coaxial configuration has a lot to offer form a naval platform.

Especially when modernized, with a top rotor with fewer blades but larger diameter than the lower rotor.

 

[nemo]

Especially when modernized, with a top rotor with fewer blades but larger diameter than the lower rotor.

Not for naval application -- due to deck space restriction and storage space limitation. Hence larger diameter is not desirable. More blade, however, is doable.

 

[delft]

Not for naval application -- due to deck space restriction and storage space limitation. Hence larger diameter is not desirable. More blade, however, is doable.

The top rotor diameter would still be the same diameter or even smaller than the diameter of the main rotor of a single rotor helicopter of the same weight.

 

[shen]

Especially when modernized, with a top rotor with fewer blades but larger diameter than the lower rotor.

what advantage does such configuration offer? Is there any proposal in existence based on this design?

 

[delft]

what advantage does such configuration offer? Is there any proposal in existence based on this design?

It saves on power and vibration. I have never seen such a design.

 

[kwaigonegin]

I'm not sure a 1.5m height difference (Super Frelon vs SH-60) for the hangars is of any real significance, whether on a 4,000 ton ship or a 13,000 ton ship. You'd have to prove that one to me. The helipad can be made to the needed specifications IMO also without much ado; as far as this goes the only important measure IMO is the bow-stern length of the helipad, regarding which a 1.275m (2.55m / 2) difference is also of little significance.



Yes. In the end we will just have to wait for the photos and for more information to come out of the PLAN.

1.5m height is about 5 ft tall! Not sure if you got the dimensions wrong or maybe you mean 1.5 ft instead otherwise 5 ft higher IS very significant in a warship where every inches count!

There is a reason why the design of Seahawks have vertical tails that are about flush with the height of the main rotor to eliminate the total height of the bird.

 

[Jeff Head]

1.5m height is about 5 ft tall! Not sure if you got the dimensions wrong or maybe you mean 1.5 ft instead otherwise 5 ft higher IS very significant in a warship where every inches count!

There is a reason why the design of Seahawks have vertical tails that are about flush with the height of the main rotor to eliminate the total height of the bird.

I am putting together a detailed comparison of the various ASW helos.

MH-60R Seahawk, NH-90 NFH, AW159 Lynx Wildcat, KA-27 Helix, Z-9C Harbin, SH-26 Super Seasprite, AS656 Panther, AW101 Merlin and the PLAN Z-8. will include all of the relevant specs, weapons, and sensors, as well as pics of the various birds.

I'll post a speperate thread in the professional forum when it is ready.