Royal Australian Navy Discussions and Updates

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Volkodav

The Bunker Group
Verified Defense Pro
Given the intermittent discussion on through deck helicopter carriers I thought the following was interesting. Modelling pretty limited (and scenario very simplistic) but worth a read.

https://www.aspistrategist.org.au/simulating-anti-submarine-warfare/

Regards,

Massive
This is basically what most professional navies worked out long ago and is the reason for the various USN CVS and SCS concepts, the RNs Escort Cruisers, Tiger Conversions, CVL conversions, Through Deck Cruisers (which evolved into the Invincible class), Italy's helicopter cruisers, then carriers and Japans DDHs.

There is actually a very good paper on Japans thinking on the matter, outlining how they originally wanted four CVS (one per hunter killer group) with Trackers and helicopters but settled on eight DDHs (two per hunter killer group) but only ever got four due to political and cost reasons. The reason behind their current through deck DDHs is to get helicopter numbers up to what is needed to contain and kill an SSN, this not just total number of helos but the number of spots to surge extra aircraft when a contact is made.

The UK has long worked on the principle that a helicopter on station can replace a frigate in the escort screen and hence why the Invincible class exist (original plans were for six of them). The more helicopters you have the better you can maintain a screen and the more effectively you can respond to a contact. If you establish the number of helos you need, including to cycle them through maintenance, as well as the number of spots you need to surge aircraft on contact. This is where a larger platform with more helicopters and more spots becomes economic as a single hull with multiple spots able to adequately support multiple helicopters becomes cheaper than buying and crewing additional escorts over and above what is required for task groups and other missions.

When you have a platform with five, six or seven spots you find it is large enough to have extensive maintenance facilities, magazines, fuel bunkers, command and control facilities, extra accommodation for specialist personnel, a hospital, even STOVL and other types covering off a wide spectrum of roles that may not otherwise be addressed. This potential and flexibility can actually be a minus as instead of concentrating on the fact that it is the most effective (including in terms of cost) way to get extra helicopters (and as importantly spots) to sea, many through ignorance or even deliberate/malicious misdirection ignore the key factor of the efficiency of the platform in enabling the require capability, i.e. X no. of ASW helos and helo spots and make it about escort numbers, alleged vulnerability, manning, STOVL fighters are more limited than CTOL ones, a CTOL carrier would be better (but unaffordable), need more than one CVH, will unbalance the force, etc. etc. The irony to provide the required number of ASW helicopters in any other way is actually more expensive, requires more manpower and will never be realised, meaning the fleet is actually less capable, less flexible and more vulnerable.
 

ASSAIL

The Bunker Group
Verified Defense Pro
Given the intermittent discussion on through deck helicopter carriers I thought the following was interesting. Modelling pretty limited (and scenario very simplistic) but worth a read.

https://www.aspistrategist.org.au/simulating-anti-submarine-warfare/

Regards,

Massive
The study is totally theoretical as noted however it does illustrate what we have known for eons. As good as helos are, and modern helos are very good, they cannot cover the TG at distance. A truism in ASW is that once the attacking sub reaches the screen the game is lost and with developments in anti ship submarine launched missiles you would have to add that once they were in range the game is lost.
What is missing from the model is fixed wing ASW both distant and organic and ASW submarines. These all limit the options open for the attacking boat as they force them into riskier options for both targeting and attack.

Subsequently, if any Flat top asset was considered it must include f/w or long endurance UAV options. ASW is always a layered strategy and unless the whole is included the risks to the TG grow exponentially
 

Volkodav

The Bunker Group
Verified Defense Pro
The study is totally theoretical as noted however it does illustrate what we have known for eons. As good as helos are, and modern helos are very good, they cannot cover the TG at distance. A truism in ASW is that once the attacking sub reaches the screen the game is lost and with developments in anti ship submarine launched missiles you would have to add that once they were in range the game is lost.
What is missing from the model is fixed wing ASW both distant and organic and ASW submarines. These all limit the options open for the attacking boat as they force them into riskier options for both targeting and attack.

Subsequently, if any Flat top asset was considered it must include f/w or long endurance UAV options. ASW is always a layered strategy and unless the whole is included the risks to the TG grow exponentially
This is where version of the Osprey are so exciting, but also of interest is US investigations into a light carrier version of the America class LPA with a catapult to increase its flexibility.
 

hairyman

Active Member
After reading that, the article posted by MASSIVE, I am firmly of the believe that Hyuga class ships would be a good buy for the RAN, especially if they are fitted with a sonar system and Asroc.
And it would probably be in our interests to fit sonar onto our LHD;s if at all possible.
 

hauritz

Well-Known Member
The article would seem to suggest is something that should not come as a surprise to anyone and that is that helicopters are very effective ASW weapons and that they a pretty much platform agnostic.

In a scenario where the navy was escorting one or both of its LHDs it is likely that extra helicopters would be based on the LHDs themselves which would remove the necessity of a specialised ASW vessel such as the Hyuga.

Australia's planned surface fleet is based around the AWDs, frigates and LHDs. If Australia did not have the LHDs and were to base its amphibious forces around LPDs instead then I could see a strong case for a ship such as the Hyuga. It would offer helicopter support for the amphibious vessels as well as a platform for ASW helicopters.
 

alexsa

Super Moderator
Staff member
Verified Defense Pro
After reading that, the article posted by MASSIVE, I am firmly of the believe that Hyuga class ships would be a good buy for the RAN, especially if they are fitted with a sonar system and Asroc.
And it would probably be in our interests to fit sonar onto our LHD;s if at all possible.

For crying out loud ...... you cannot simply fit sonar into the LHD. There are structural considerations you need to take into account and it is not a simple process of gluing it on.


A large modern SONAR (have a look at the bow of Hobart) is not a small item and needs structure to support it and the stresses it places on the hull. This would mean you have to cut a reasonable size hole in the vessel and then reinforce/reconfigure and longtitudinal and transverse framing that may be effected .... and it will be.


That is before you fit the consoles in the operations room as well as the power and communications infrastructure.


Finally you have to confirm that the vessel is actually a suitable platform for a hull mounted SONAR. Looking at the FFG as an example, the cost of retrofitting the extended stern on the first three vessels make the Seahawk purchase one of the most expensive systems deployed at that time.


For the likely cost of just buggering up the LHD structure why not ...... buy more helicopters.


Noting the fact we only have 24 of these and have more decks that we can currently use this would be a much better investment than a DDH which is either a carrier or comparable combatant than a future frigate.... also noting the DDH will cost more to own and run.


If we are going to advocate for another 'air' platform then the pipe dream of a light carrier would appear to be a better option ...... however, that issue has been discussed ad nausium before and unless we going to get F35B and more helicopters this is not going to happen nor is it worthwhile.
 

Stampede

Well-Known Member
Given the intermittent discussion on through deck helicopter carriers I thought the following was interesting. Modelling pretty limited (and scenario very simplistic) but worth a read.

https://www.aspistrategist.org.au/simulating-anti-submarine-warfare/

Regards,

Massive
Hi Massive

Thanks for the link.

Another from ASPI, this one discussing UAV's which you may have read and others may find of interest.

www.aspistrategist.org.au/pointy-end-better-bigger/

My personal view is that UAV development will move faster than that of ships to accomodate them. The single hangar ANZAC's like many of there contempories will sail on still for many years and be limited in space to a single helicopter or a number of smallar UAV's.
Maybe we should think diffferently about being impressed with our future destroyer having two helicopter's.
Should we now be looking at a flight deck and hangar for two medium helicopter / UAV's backed up with a smaller flight deck with a further accomodation for say three smaller size ( 200kg Sized ) UAV's.
Such a ship will need to be crewed and have the full ability to fuel and service such an aviation compliment.
A thought for the future.

Regards S
 

Volkodav

The Bunker Group
Verified Defense Pro
Only my personal opinion but in the future I wouldn't be surprised if most surface combatants from large frigates upwards will of through deck design. This is because of the increasing important of various unmanned vehicles, the increasing utility of 3-D printing, the prevalence of VLS, the evolution of directed energy weapons, the superiority of a through deck for sensor coverage and communications, and everything else the extra volume will enable.

There will likely still be conventional configuration smaller combatants and some specialist bigger ships but a large clear deck, large hanger/garage spaces and workshops just offer so much.
 

gf0012-aust

Grumpy Old Man
Staff member
Verified Defense Pro
For crying out loud ...... you cannot simply fit sonar into the LHD. There are structural considerations you need to take into account and it is not a simple process of gluing it on.


A large modern SONAR (have a look at the bow of Hobart) is not a small item and needs structure to support it and the stresses it places on the hull. This would mean you have to cut a reasonable size hole in the vessel and then reinforce/reconfigure and longtitudinal and transverse framing that may be effected .... and it will be.


That is before you fit the consoles in the operations room as well as the power and communications infrastructure.


Finally you have to confirm that the vessel is actually a suitable platform for a hull mounted SONAR. Looking at the FFG as an example, the cost of retrofitting the extended stern on the first three vessels make the Seahawk purchase one of the most expensive systems deployed at that time.


For the likely cost of just buggering up the LHD structure why not ...... buy more helicopters.


Noting the fact we only have 24 of these and have more decks that we can currently use this would be a much better investment than a DDH which is either a carrier or comparable combatant than a future frigate.... also noting the DDH will cost more to own and run.


If we are going to advocate for another 'air' platform then the pipe dream of a light carrier would appear to be a better option ...... however, that issue has been discussed ad nausium before and unless we going to get F35B and more helicopters this is not going to happen nor is it worthwhile.
you'd have to structurally chew into a 1/4 to a 1/3rd of the hull - a non trivial exercise

and then there is the citadel where the cable harnesses would have to be modified, and that would means recertification at all the bulkhead points etc...

it just doesn't make sense to do it - there are far easier ways to get enhanced capability to the task force
 

ngatimozart

Super Moderator
Staff member
Verified Defense Pro
Only my personal opinion but in the future I wouldn't be surprised if most surface combatants from large frigates upwards will of through deck design. This is because of the increasing important of various unmanned vehicles, the increasing utility of 3-D printing, the prevalence of VLS, the evolution of directed energy weapons, the superiority of a through deck for sensor coverage and communications, and everything else the extra volume will enable.

There will likely still be conventional configuration smaller combatants and some specialist bigger ships but a large clear deck, large hanger/garage spaces and workshops just offer so much.
Disagree, because you don't need thru deck designs to operate more helos / UAS. You just increase the flight deck, workshop and hangar sizes if need be, whilst retaining the conventional layout. The helicopter cruisers from the 1960s were arguably flawed, however having a maximum of four helos and / or UAS on modern DDs would necessitate something similar. If you want more then go for a thru-deck design but that would be a specific vessel type and may not offer the versatility and benefits (cost, crewing etc.,) that a large flight deck conventional DDG may offer.
 

Massive

Well-Known Member
... and have more decks that we can currently use
Interestingly if you had an escort group of an AWD, 3 Future Frigates and a Cantabria you would have space for 8 helicopters.

Pretty potent and leaving the LHDs to focus on amphibious operations.

As you would know where you are going this could be supported with subs, P-8s and BAMS.

Would be very effective for the type of independent scenarios the RAN might be required to operate in.

Regards,

Massive
 

Massive

Well-Known Member
Should we now be looking at a flight deck and hangar for two medium helicopter / UAV's backed up with a smaller flight deck with a further accomodation for say three smaller size ( 200kg Sized ) UAV's.
Thanks Stampede,

Did a fair bit of reading on this recently.

Think with ASW the key is getting a UAV big enough to do something useful - would need to carry either sonobuoys or a dipping sonar to be really useful. Then you would need a helicopter (or a really big UAV) or ASROC to deliver a torpedo to any target.

Given pace of change, may well be here sooner than I think though.

Question for you though would be do they really need a separate flight deck - hangar space may be more the critical factor.

Regards,

Massive
 

zhaktronz

Member
Thanks Stampede,

Did a fair bit of reading on this recently.

Think with ASW the key is getting a UAV big enough to do something useful - would need to carry either sonobuoys or a dipping sonar to be really useful. Then you would need a helicopter (or a really big UAV) or ASROC to deliver a torpedo to any target.

Given pace of change, may well be here sooner than I think though.

Question for you though would be do they really need a separate flight deck - hangar space may be more the critical factor.

Regards,

Massive
I'd honestly suggest that self deploying small drone sonobouys (20-30km range?) are probably already feasible.
 

swerve

Super Moderator
After reading that, the article posted by MASSIVE, I am firmly of the believe that Hyuga class ships would be a good buy for the RAN, especially if they are fitted with a sonar system and Asroc.
And it would probably be in our interests to fit sonar onto our LHD;s if at all possible.
Hyuuga & Ise have great big sonars in their bows. See here. It'd be bloody hard to fit that to an LHD. You're talking about a major rebuild.

Buying Hyuugas would be pointless without a lot more helicopters, more helicopter crews, etc. & more ship crews. You're asking for a big expansion in the RAN. This topic has been beaten to death.
 

gf0012-aust

Grumpy Old Man
Staff member
Verified Defense Pro
I'd honestly suggest that self deploying small drone sonobouys (20-30km range?) are probably already feasible.
and more - they're a standard NATO dispenser that are already "used" within the ROV/UAS community and there have been a number of developments underway in the last few years

especially as some can be manually ejected
 

vonnoobie

Well-Known Member
We want more ASW capability, then let's simplify it and invest in a program that wont require more pilot's or heavily modifying our force make up or the types of ships we have.

Go to DARPA with some dollars and invest into there ACTUV program, The Sea Hunter is already in the water and so far has met or exceeded the initial test requirements, with follow on test requirements (2017 or 2018) to test the ISR and ASW capability.

With it's stated ability to operate in sea state 5 and survive sea state 7, 19,000km range, 27 knot speed and cheap operating cost it is an ideal program to jump in early.

I see this as being far more realistic then getting new bigger more crew intensive ships, laying up current ships for a long and risky modification or in some respect getting more Sea hawks.

With it's range and endurance this vessel or a future type of it could perform ASW, ISR, MCMV etc freeing up our larger assets and greatly increasing our fleets capability.
 

gf0012-aust

Grumpy Old Man
Staff member
Verified Defense Pro
Can you share the designation?

Surprised this can be carried on a 200kg UAV.

Regards,

Massive
Unsure of STANAG - but its an industry standard reference as a whole pile of UAS and ROV's are being designed around the tube diameter. Sea-Tech and Ocean News both have run recent publications on sonarbuoy sized capabilities that can be launched from fixed and rotary ASW as some surface based munitions dispensers
 

ASSAIL

The Bunker Group
Verified Defense Pro
Thanks Stampede,

Did a fair bit of reading on this recently.

Think with ASW the key is getting a UAV big enough to do something useful - would need to carry either sonobuoys or a dipping sonar to be really useful. Then you would need a helicopter (or a really big UAV) or ASROC to deliver a torpedo to any target.

Given pace of change, may well be here sooner than I think though.

Question for you though would be do they really need a separate flight deck - hangar space may be more the critical factor.

Regards,

Massive
You need a large f/w UAV capable of covering about 15,000 square miles 50-80 nms ahead of the line of advance. And capable of launching weapons. This roughly replicates what organic fixed wing could do. The P8's would be much further out 100-200 roughly. This constitutes layered defence and the desired detection, location and prosecution of the target would always occur way beyond the screen.
 

Volkodav

The Bunker Group
Verified Defense Pro
Yep exactly. With the loss of the CVS the RAN effectively lost not one but three layers of ASW. The Trackers, the Sea Kings and Ikara, which relied on helicopters fixing target submarines outside the detection range of the ships sonar.

It actually surprises me that no effort was made to increase the numbers of MPAs or combat aircraft in the RAAF, or to acquire surface platforms capable of operating the Sea Kings to at least mitigate the lack of a carrier. The capabilities just completely disappeared without replacement or substitution.
 
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