Fantasy RAN thread (Surface Ships & LHDs only)

[Git_Kraken]

Any news on increasing the VLS capacity on the Hunters?

I would be very surprised if Australia was able to increase the VLS capability beyond the 32 they are proposing. That ship is very close to the design margins as it is. With a large heavy radar up high it really limits you in what you can do. The T26 was designed for a much smaller lighter radar than the CEAFAR system. And weight up high really restrict weight down low in a ship.

 

[oldsig127]

The T26 was designed for a much smaller lighter radar than the CEAFAR system. And weight up high really restrict weight down low in a ship.

Say what? I thought that weight down low was part of the counter to weight up high.

oldsig

(Clearly I'm the wrong sort of engineer)

 

[ddxx]

I would be very surprised if Australia was able to increase the VLS capability beyond the 32 they are proposing. That ship is very close to the design margins as it is. With a large heavy radar up high it really limits you in what you can do. The T26 was designed for a much smaller lighter radar than the CEAFAR system. And weight up high really restrict weight down low in a ship.

I very much doubt that assumption.

If Hunter, with a light ship weight of 8,200 tonnes and a full load displacement of or exceeding 10,000 tonnes (per senate estimates) doesn’t have any margin for more than 32 cells something is seriously wrong with the design.

 

[SD67]

I very much doubt that assumption.

If Hunter, with a light ship weight of 8,200 tonnes and a full load displacement of or exceeding 10,000 tonnes (per senate estimates) doesn’t have any margin for more than 32 cells something is seriously wrong with the design.

I see the confusion. I wasn't clear by "weight down low". I should have been more technical. Mea Culpa.

Apologies for what follows. I'm over-explaining for those here who might not understand the physics of ship stability as the board is a mix of technical and non-technical experts.

It depends on where the center of gravity is and where the waterline is. To properly counterbalance you need to create that righting arm equation which includes all the counterbalances and buoyancy. A weight near the CoG of the ship (VLS for example) either does nothing or exacerbates the problem as the ship heels and VLS ends up creating a moment. Actually, I wouldn't be surprised if more VLS raised the ships CoG higher.

To properly deal with a heavy radar you need a heavier weight as far below the waterline as you can, which often ends up being ballast in a ship that is "modified" as Hunter Class will be. Ballast is wasted design margin. It adds nothing to fight the ship. I've seen 6 to1 and greater ballast to equipment ratios for weight caused by new installs on masts. The ratios get large because of buoyancy and distance.

I'm a combat systems guy, but have been through enough refits and projects to know generally how combat systems impact the Nav Archs. I would be shocked if the T26 wasn't optimized based on the equipment as BAE knows what they are doing. This means modifications for Hunter have certain limitations/restrictions. And likely is one of the reasons they are up against the design margins as reported above.

I'm not saying more VLS isn't possible, what I am saying is that it will be hard to do without tradeoffs somewhere else (perhaps the removal of the FC illuminator as the SM family and ESSM family are going to be active missiles in the near future).



I can only go from the article I posted. A margin of 270 tonnes is very tight. The addition of 8 more VLS with missiles inside them could gobble up all that margin.

Hey thanks for the info. In your experience is this sort of margin typical at this stage and if not do you see any trades that could be made in T26->Hunter ( ie things like the mission space or chinook capable flight deck)?

 

[spoz]

As noted stability depends on the difference between the centre of gravity and the centre of buoyancy, particularly the vertical distance between the two in this discussion. See here 6 basics that will make the ship stability easy to understand - MySeaTime for a simple explanation of stability.

It might be in the interests of the board if there was a “this is stability” thread for people new to the concepts. It could include some insights as to how ship displacement, gross carrying capacity and several other essential ship design matters are conventionally discussed.

In most installations, the Hobarts for example, the Mk 41 extends from below the centre of buoyancy to above it. The effect on stability of increasing the number of cells depends on how much is below, and by how much, and how much is above and by how much, and of course varies depending on whether the cells are full or empty. And as each moves around as you add or remove weight, it is always an interesting calculation. It can be pretty embarrassing if you get it wrong Disastrous moment brand new ship capsizes right after launch, although launch is a specific situation as the way in which the weight Is supported changes through the evolution.

Then there is calculating stability in submarines, or semi displacement hulls. There is is a reason naval architects are paid the big bucks (well, sort of).

For intermediate level readers, look up “inclining experiment” on the internet.

 

[ddxx]

I can only go from the article I posted. A margin of 270 tonnes is very tight. The addition of 8 more VLS with missiles inside them could gobble up all that margin.

In the Senate estimates they also explained that this is because Hunter will be fully fitted with from the get go, rather than fitted for but not with. They also mentioned that the hull has been lengthened, by how much we don't know.

Given that Defence has never actually confirmed the number of cells on Hunter, alongside the displacement and planned load out of SM-2, ESSM and now SM-6 (if not other weapons too), I'd be very surprised if Hunter doesn't have 48 - 64 cells from ship one, batch one.

 

[76mmGuns]

About the Hunter class and it's missiles load, I've always felt, in my amateur opinion, that the multimission space could either fit VLS, or in lieu of that, have a bunch of deck mounted launchers with an angled wall for stealth, similar to the Tuo Chiang missile corvette arrangement. Apparantly the ship has 28 missiles, with 12 x anti ship/surface missiles, and 4 x4 packed anti air missiles. The beam is 14m, I think, so the Hunter has plenty of space for more missiles. So a Guided Missile Destroyer version could be made.

And fore, given the UK Type 26 missile arrangement, perhaps up to 64/72 Mk41 could be jammed up there, though it's hard to tell without a cross sectional diagram showing what's within 6.6-8m under the deck.

https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/ROCN_PGG-618_model_at_RF6_20181027.jpg/1280px-ROCN_PGG-618_model_at_RF6_20181027.jpg

 

[ddxx]

About the Hunter class and it's missiles load, I've always felt, in my amateur opinion, that the multimission space could either fit VLS, or in lieu of that, have a bunch of deck mounted launchers with an angled wall for stealth, similar to the Tuo Chiang missile corvette arrangement. Apparantly the ship has 28 missiles, with 12 x anti ship/surface missiles, and 4 x4 packed anti air missiles. The beam is 14m, I think, so the Hunter has plenty of space for more missiles. So a Guided Missile Destroyer version could be made.

And fore, given the UK Type 26 missile arrangement, perhaps up to 64/72 Mk41 could be jammed up there, though it's hard to tell without a cross sectional diagram showing what's within 6.6-8m under the deck.

https://upload.wikimedia.org/wikipedia/commons/thumb/0/07/ROCN_PGG-618_model_at_RF6_20181027.jpg/1280px-ROCN_PGG-618_model_at_RF6_20181027.jpg

From everything I've read and seen on the topic, I don't think you would need to chew up the mission bay in fitting more cells.

The "angled wall for stealth" is a very interesting point - I've often wondered why the Global Combat Ship base design doesn't include these midship to hide deck equipment to reduce radar cross-section. Most modern designs tend to incorporate this and they're usually light-weight composite, so weight wouldn't likely be the issue.

Here's a good example of this on Japan's new Mogami Class:

 

[John Newman]

About the Hunter class and it's missiles load, I've always felt, in my amateur opinion, that the multimission space could either fit VLS, or in lieu of that, have a bunch of deck mounted launchers with an angled wall for stealth, similar to the Tuo Chiang missile corvette arrangement. Apparantly the ship has 28 missiles, with 12 x anti ship/surface missiles, and 4 x4 packed anti air missiles. The beam is 14m, I think, so the Hunter has plenty of space for more missiles. So a Guided Missile Destroyer version could be made.

And fore, given the UK Type 26 missile arrangement, perhaps up to 64/72 Mk41 could be jammed up there, though it's hard to tell without a cross sectional diagram showing what's within 6.6-8m under the deck.

I think you need to ask yourself a few questions first about the Hunter class FFG.

Is their primary role AAW or ASW?

The answer is ..... ASW.

And as such the multi mission bay will be used for things such as an additional ASW helicopter, USV, UUV or UAV or a combination.

You delete or significantly reduce the size of that bay, then the end result is the ship is compromised for its primary role.

Regardless of more VLS for AAW weapons, it still has a pretty decent AAW capability.

Another question is the Hunter a good basis for a DDG? Maybe, maybe not.

Cheers,

 

[76mmGuns]

I think you need to ask yourself a few questions first about the Hunter class FFG.

Is their primary role AAW or ASW?

The answer is ..... ASW.

And as such the multi mission bay will be used for things such as an additional ASW helicopter, USV, UUV or UAV or a combination.

You delete or significantly reduce the size of that bay, then the end result is the ship is compromised for its primary role.

Regardless of more VLS for AAW weapons, it still has a pretty decent AAW capability.

Another question is the Hunter a good basis for a DDG? Maybe, maybe not.

Cheers,

It depends. There's a graphic back around page....1000?, I forget which, where the timetable of the sovereign naval building is shown, and around late 2030's, 3 Hunters are shown as being AAW replacing the Hobarts. I have it on my phone, but I'm typing from a work computer atm.

imho, our Hunter's are actually an all in one frigate, with AAW but unlike Hobarts, also with excellent ASW features. A pure ASW doesn't necessarily need a high mast with a radar going out to 400+ km. But we can't afford several groups of front end ships like, say the UK has, with type 23 and type 45's.

Disclaimer- I am aware I'm an armchair amateur enthusiastic

 

[John Newman]

It depends. There's a graphic back around page....1000?, I forget which, where the timetable of the sovereign naval building is shown, and around late 2030's, 3 Hunters are shown as being AAW replacing the Hobarts. I have it on my phone, but I'm typing from a work computer atm.

imho, our Hunter's are actually an all in one frigate, with AAW but unlike Hobarts, also with excellent ASW features. A pure ASW doesn't necessarily need a high mast with a radar going out to 400+ km. But we can't afford several groups of front end ships like, say the UK has, with type 23 and type 45's.

Disclaimer- I am aware I'm an armchair amateur enthusiastic

Yes it’s true there is a plan to replace the 3 x Hobart DDG when the 9 x Hunter FFG program is completed, yes all part of the continuous Naval Shipbuilding Plan, and yes should commence in the late 2030s or early 2040s.

But what isn’t true is that a design has been selected (eg, a Hunter DDG) or how many DDG replacements to be built.

The first Hunter FFG hasn’t completed being designed or even started construction.

I wouldn’t hold my breath either way yet.

Cheers,

 

[Reptilia]

Yes it’s true there is a plan to replace the 3 x Hobart DDG when the 9 x Hunter FFG program is completed, yes all part of the continuous Naval Shipbuilding Plan, and yes should commence in the late 2030s or early 2040s.

But what isn’t true is that a design has been selected (eg, a Hunter DDG) or how many DDG replacements to be built.

The first Hunter FFG hasn’t completed being designed or even started construction.

I wouldn’t hold my breath either way yet.

Cheers,

My money is on the type 45 successor, a modified type 83 (4-5).
first one expected in late 2030s for the RN, 5+ years before we begin the hobart replacement.

 

[ADMk2]

My money is on the type 45 successor, a modified type 83 (4-5).
first one expected in late 2030s for the RN, 5+ years before we begin the hobart replacement.

A bit far out I’d suggest, plus the experience of taking a British ship, fitting it with Australian radar and American combat systems and weapons systems, will inform this process to a significant degree I’d expect…

 

[StingrayOZ]

The move from Anzac's to Hunters provides a huge leap in missile capacity. 8 quad packed cells to 32 quad packed cells. No CIWS to 2 x CIWS (or CAMM). The hunters have much better sensors and situational awareness and electronic and decoy capability.

I find the missile capacity to be satisfactory. What you want is long range munitions. If they carry 16 x SM-6 (or TLAM) and 8 x LRASM that is a very significant long range capability. You want a long range radar. It can embark an helo and several drones. For a "Frigate" they are extremely capable.

The idea that lone Australian frigates will engage Chinese destroyers in a 1 v 1 and exchange missiles until magazines are empty is doubtful. If the two ships ever do make contact, that with the best sensors will likely win the engagement (dismounted or mounted). Magazine capacity, as much as it has mostly been is theoretical.

The Hobarts are pretty good at ASW, the hunters are better. The hunters are pretty good at AAW/ASuW, the hobarts are better.

Its tempting to upscale everything to you get to a cruiser/battleship/deathstar. But is that a good use of people and money for a navy like the RAN?
Rather than jamming more missiles onto already loaded platforms. I would argue build more ships.

Australia already has the capability to refuel a reactor, we refuel the mid enriched OPAL reactor. But the main advantage of a sealed for life reactor is how much lower your operation costs, and more availability you get. Nuclear submarines can now approach diesel submarines for availability.

 

[76mmGuns]

Its tempting to upscale everything to you get to a cruiser/battleship/deathstar. But is that a good use of people and money for a navy like the RAN?
Rather than jamming more missiles onto already loaded platforms. I would argue build more ships.

I think that's fair enough.

Though I wouldn't mind "build more Death Stars", to paraphrase you

 

[Todjaeger]

The move from Anzac's to Hunters provides a huge leap in missile capacity. 8 quad packed cells to 32 quad packed cells. No CIWS to 2 x CIWS (or CAMM). The hunters have much better sensors and situational awareness and electronic and decoy capability.

I find the missile capacity to be satisfactory. What you want is long range munitions. If they carry 16 x SM-6 (or TLAM) and 8 x LRASM that is a very significant long range capability. You want a long range radar. It can embark an helo and several drones. For a "Frigate" they are extremely capable.

The idea that lone Australian frigates will engage Chinese destroyers in a 1 v 1 and exchange missiles until magazines are empty is doubtful. If the two ships ever do make contact, that with the best sensors will likely win the engagement (dismounted or mounted). Magazine capacity, as much as it has mostly been is theoretical.

The Hobarts are pretty good at ASW, the hunters are better. The hunters are pretty good at AAW/ASuW, the hobarts are better.

Its tempting to upscale everything to you get to a cruiser/battleship/deathstar. But is that a good use of people and money for a navy like the RAN?
Rather than jamming more missiles onto already loaded platforms. I would argue build more ships.

Honestly I would like it if the RAN missile capacity could be expanded to a degree, with the caveat that Australia would also need to establish and maintain sufficient warstocks of missiles to actually fill the increased number of VLS cells.

Also, looking at scenarios where it is a lone RAN vessel involved in a missile exchange is incorrect thinking, at least IMO. What I think is a more likely scenario would be RAN vessels or a TF with high value assets being subjected to saturation attacks, not unlike the USN and NATO allies planned for in 1980's era Cold War scenarios. If the security situation with the PRC devolves into shooting situations, I do believe some potential scenarios would involve volleys of AShM launched from PLAAF H-6 aircraft. With the PLAAF believed to have quite a few (100+ IIRC) H-6 in service, and with various missile loadouts available, a flight of ~24 H-6 sortied for a maritime strike launching 100+ AShM is something I believe is a realistic possibility. IIRC the Cold War scenarios NATO planned for were Tu-22 'Backfire' sorties of 100+ aircraft each carrying a single, large and long-ranged AShM for use in saturation maritime strikes targeting shipping and naval vessels bringing personnel and kit from North America to Europe.

As I understand it, it will be some time before the Hunter-class build programme is complete, so likely RAN escorts in a task force with an LHD and/or AOR would likely consist of a Hobart-class DDG (48 VLS cells), a Hunter-class FFG (32 VLS cells) and possibly an ANZAC-class FFH (8 VLS cells). Yes, if all of the VLS cells consisted of quad-packed ESSM or ESSM Block II, that would be 352 missiles effective out to ~50 km. However I would expect at least some of those VLS cells to carry longer-ranged missiles like SM-2 or even SM-6. With that in mind, being able to increase the loadout of existing and planned vessels could be beneficial IMO.

 

[StingrayOZ]

Though I wouldn't mind "build more Death Stars", to paraphrase you

Well we will see.

The largest American cruiser currently is the Ticonderoga at 9600t. Hunter looks to be bigger than that.
The Korean StG is around 11,000t, being a slightly scaled burke. Which is about rumored displacement of the hunters.
The Japanese Maya class is around 10,250t. Which again is around the rumored size of Hunter.

While all of these have large missile capacities, the Hunters are a frigate with "some AAW". Hunters will often embark a helicopter or more, while many of these destroyers/cruisers, don't. They are based around other benchmarks other than magazine capacity.

As with the AWD, building four, in hindsight would have been an obvious, useful and cheap way to improve capability. Certainly better than trying to up arm the Hobarts after they were designed or worse, after they were built. Particularly if you have a hot production line.

Getting us back to 14 surface combatants should be a realistic dream. May cost similar to the existing 12 plan.

I would imagine any destroyer based off the T26 design, would carry a lot more than 32.

As I understand it, it will be some time before the Hunter-class build programme is complete, so likely RAN escorts in a task force with an LHD and/or AOR would likely consist of a Hobart-class DDG (48 VLS cells), a Hunter-class FFG (32 VLS cells) and possibly an ANZAC-class FFH (8 VLS cells). Yes, if all of the VLS cells consisted of quad-packed ESSM or ESSM Block II, that would be 352 missiles effective out to ~50 km. However I would expect at least some of those VLS cells to carry longer-ranged missiles like SM-2 or even SM-6. With that in mind, being able to increase the loadout of existing and planned vessels could be beneficial IMO.

Prevention is better than cure. Longer range missiles that are able to take out platforms before launching, or are forced to launch with vague targeting data is better than trying to mop up a saturation attack.

Australia seems to have a large SM-2 warstock. While FMS actual orders aren't public the requests are, 80 sm2 III for the AWD, FFG SM-2's (some 175), which we kept and chile had to buy new SM-2 from the US. Some 250 SM-2 is probably a reasonable stock. Australia seems to have order ~50 Sm missiles of a mix of IIC and SM-6.

IMO a larger order of SM-6 would be highly desirable, particularly as hunters come on line. Hobarts will be carrying Tomahawk as well. So Australia has a fairly large missile stock. Its shortage to deploy that is the issue.

Increasing the existing VLS load out is somewhat difficult. The Anzacs are maxed. The Hobarts have minimal scope, particularly after they receive their radar/combat upgrade, which may consume their entire margin. The Hunters too, are apparently fairly "tight" for margin.

If we want to defend a fleet of a LHD, DDG and a FFH, from an attack from heavily armed 24 x H6's, we may need to look at alternatives other than cramming more missiles. Our fleet wasn't designed around two surface combatants defending themselves from 100 launched missiles, from squadrons of aircraft.

Frigates and are not designed to take out squadrons of long range bombers.
Even if you did, they would simply re-arm and reattack. In a few hours the fleet may have moved tens of miles, not a problem for a rearm and reattack.

 

[ddxx]

Getting us back to 14 surface combatants should be a realistic dream. May cost similar to the existing 12 plan.

The report by the ANU on the Hunter program certainly suggests that could be an option given the substantial premium being budgeted for a slower 'drumbeat'.

I would imagine any destroyer based off the T26 design, would carry a lot more than 32.

With a length of 149.9 and a beam of 20.8 - the T26/Hunter beam should allow for a 10-15 metre plug based on L/B ratio.

 

[SD67]

The report by the ANU on the Hunter program certainly suggests that could be an option given the substantial premium being budgeted for a slower 'drumbeat'.



With a length of 149.9 and a beam of 20.8 - the T26/Hunter beam should allow for a 10-15 metre plug based on L/B ratio.

My understanding is that the Beam to draught ratio, and also the engines being mounted above the waterline place some limitations on the "T26 as a DDG" scenario . There was a post on one of the other sites on this from an expert, I'll see if I can dig it up. It is by no means certain that T26 is going to be the basis of T83 (the T45 replacement), all options are being considerd.

 

[StingrayOZ]

The report by the ANU on the Hunter program certainly suggests that could be an option given the substantial premium being budgeted for a slower 'drumbeat'.

There is the possibility to allow it. 14 surface combatants isn't an impossibility or unreasonable. Even in peace time.

The actual cost would be minimal increase in the over all project cost.

With a length of 149.9 and a beam of 20.8 - the T26/Hunter beam should allow for a 10-15 metre plug based on L/B ratio.

It would be more than just a stretch, I would looking at reconfiguring the flex space area. Making at much more focused and capable destroyer. With significant land attack and BMD capabilities in addition to AAW. SM-3, SM-6, ESSM Blk2, Tomahawk, LRASM. More power, better sustained speed. etc.
It may not be a stretch at all, but rather a ship inspired by Hunters/t26 supply lines and design philosophies. Moving to a 14 ship fleet could enable a 5-6 ship build. If built in conjunction with the UK building 6, that would be reasonable build volume.