Re: Future ASW
Posted: 26 Sep 2019, 09:13
well then the way round this is for A-140 is to have the stern ramp fitted to the below deck mission space this would also allow RM to deploy something like CB-90
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Weapon deck (as on IHs, the originals) was already mentioned. What has been done with that space in the modified design?Poiuytrewq wrote:the current configuration uses the available space very inefficiently.
"something like" being its lighter version at 10.8 mtrs (ARCIMS being 11m /10 t).Tempest414 wrote:this would also allow RM to deploy something like CB-90
I guess it is upside-down. Arrowhead 140 as a T31 is adopting very large hull, which is incompatible with its cost. I hope RN knows it. To be upgraded for normal escort, Arrowhead 140 is a good design. But, for multi-purpose role, it is not (Absalon-design should have been better). I still think Leander has no shortage compared to Arrowhead 140 (because of very low cost attributed), but the decision has been already done.Poiuytrewq wrote:The Arrowhead 140 in its T31 guise continues to be a superbly capable design completely hamstrung by a woefully inadequate budget.
Agreed. RN is spending almost the entire budget on the very best hull that can be acquired for that price. The problem is I don't believe it will be optimised for RN use. Costly re-fits down the line are the inevitable outcome.donald_of_tokyo wrote:Arrowhead 140 as a T31 is adopting very large hull, which is incompatible with its cost.
Very little. Two extra boat bays added to meet requirements.ArmChairCivvy wrote:Weapon deck (as on IHs, the originals) was already mentioned. What has been done with that space in the modified design?
An under flight deck misson area would be a great addition for any GP Frigate especially if the stern ramp was capable of deploying large off-board systems and/or a containerised towed array.Tempest414 wrote:...for A-140 is to have the stern ramp fitted to the below deck mission space....
I complete agree here the A140 is a good design that has lots of potential if money is forth coming but so is the absalon design which also offers greater flexibility.donald_of_tokyo wrote:I guess it is upside-down. Arrowhead 140 as a T31 is adopting very large hull, which is incompatible with its cost. I hope RN knows it. To be upgraded for normal escort, Arrowhead 140 is a good design. But, for multi-purpose role, it is not (Absalon-design should have been better). I still think Leander has no shortage compared to Arrowhead 140 (because of very low cost attributed), but the decision has been already done.Poiuytrewq wrote:The Arrowhead 140 in its T31 guise continues to be a superbly capable design completely hamstrung by a woefully inadequate budget.
A bit off-topic....
If more money is needed to put some improvements in Arrowhead 140 design, I can propose to "degrade" 2 of the 5 T31 hulls. Building 2 "Floreal-like" glorified OPV without CAMM, and 3 "GP frigate" with CAMM, both with adequate boat-bay design, as well as SSM and hull-sonar added. Use 2 of the "GP frigate" version to be forward deployed (while 1 in maintenance), and use 1 of the "Floreal-like" version for training of "rotating crew" at British home water (while 1 in maintenance).
Yet again you are off on one of your little fantasies.donald_of_tokyo wrote:I guess it is upside-down. Arrowhead 140 as a T31 is adopting very large hull, which is incompatible with its cost. I hope RN knows it. To be upgraded for normal escort, Arrowhead 140 is a good design. But, for multi-purpose role, it is not (Absalon-design should have been better). I still think Leander has no shortage compared to Arrowhead 140 (because of very low cost attributed), but the decision has been already done.Poiuytrewq wrote:The Arrowhead 140 in its T31 guise continues to be a superbly capable design completely hamstrung by a woefully inadequate budget.
A bit off-topic....
If more money is needed to put some improvements in Arrowhead 140 design, I can propose to "degrade" 2 of the 5 T31 hulls. Building 2 "Floreal-like" glorified OPV without CAMM, and 3 "GP frigate" with CAMM, both with adequate boat-bay design, as well as SSM and hull-sonar added. Use 2 of the "GP frigate" version to be forward deployed (while 1 in maintenance), and use 1 of the "Floreal-like" version for training of "rotating crew" at British home water (while 1 in maintenance).
No evidence I have. My first point is, many growth margin = FFBNW places left, is all designed to be so, and there is no “opportunity lost”. Nothing.Aethulwulf wrote:Do you have any real evidence to back this up? All the evidence there is points to the fact that the hull is a very good design that is exceptionally cheap to construct. Just because it is bigger than Leander does NOT mean it is more expensive.
Agreed. And it means, RN is not at all thinking of adding USV based ASW capability to T31.As to the boat bays, if the RN wants a bigger boat bay they only have ask. The change from 4 equal sized bays to 2 large and 2 small could be done at almost zero cost at this stage. However, there is a good reason why the RN wants to be able to use 4 good sized RHIBs. The RNs definition of an adequate size for a boat bay may not be the same as yours, particularly given that yours appears to be based on one example of an unmanned system performing a role not currently required of the T31.
No objection. There is zero chance of adding USV based ASW capability to T31, as you say.There is zero chance that the RN is going to sacrifice ship survival by removing CAMM. Please stay real.
I don’t believe that is necessarily correct this is a product that has developed out of a mod dstl programdonald_of_tokyo wrote:No objection. There is zero chance of adding USV based ASW capability to T31, as you say.
Well there sure as heck split when the off board system is deployed! There certainly not connected by command wire.Poiuytrewq wrote:An ISO may contain the command module for a davit deployed offboard system but if the ISO's are part of the same package as the off-board systems is it really credible to split them up, half a ships length apart from the boats bays and bury them under a flight deck?
I think you missed my point. "The same size" = standardization is the key.SW1 wrote:I don’t believe that is necessarily correct this is a product that has developed out of a mod dstl program ...donald_of_tokyo wrote:No objection. There is zero chance of adding USV based ASW capability to T31, as you say.
We simply do not know sizing and shapes of the final design and as I’ve said previously if on only deploying one or two is a good use of boat bays on a frigate when Martinez security roles which uses ribs maybe more useful.
I did not say there is zero chance of adding USV based ASW capability to T31.donald_of_tokyo wrote:There is zero chance of adding USV based ASW capability to T31, as you say.
As this is future ASW thread, and many here (including me) think adding shallow water ASW is meaningful, my proposal comes in.
... or, "blow" a hole through the whole width of the ship, using the void for the weapons deck (and below). Two boats suddenly grow to 4;Aethulwulf wrote:do they choose one capability, but loose another? I don't know.
A USV doing up to 14kts with a 10 day endurance isn’t bad specially as it can be refuelled at sea. If your looking for standardisation then would it perhaps make sense to start with a platform that replicates current RN ribs as standard for your first go a unmanned USVs? The RN currently doesn’t have any USVs in service so it has yet to standardise on anything, the MAST program has resulted in a number of configurations and sizes, the current one is MAST-13 which is 13m long too big for type 26. Perhaps we will see a variety of platforms all using a common c&c system that can be bolted on any boat.donald_of_tokyo wrote:I think you missed my point. "The same size" = standardization is the key.SW1 wrote:I don’t believe that is necessarily correct this is a product that has developed out of a mod dstl program ...donald_of_tokyo wrote:No objection. There is zero chance of adding USV based ASW capability to T31, as you say.
We simply do not know sizing and shapes of the final design and as I’ve said previously if on only deploying one or two is a good use of boat bays on a frigate when Martinez security roles which uses ribs maybe more useful.
It is no problem if ASW drones were kept within ~9.5m. But, if so, why T26 has such a large mission bay? It is very clear the larger the drone is, the better its endurance and speed.
I like "SeaDrix" very much. But, its range and speed is not that good. This can be easily solved by increasing its size to 9.5 m, or 11m. If it is 11m long, it will be 3 times bulky than the original SeaDrix. With this size, increasing it top-speed to 20kts, and its range in 16kt to be doubled will be easy. At the same time, automatic guidance system, sensor and weapon system can be the same as the original 7.7m version. So, making it 3 times heavier will not mean it being 3 times more expensive.
This is one example, but history tells us a newly introduced weapon system quickly evolves in its size. See ScanEagle evolving into Blackjack. Yes, at some point in future, it stops growing. Where? In this case, T26's mission bay size will be one threshold. (If more larger, it will be PSVs or Bay-class LSD to carry them.) This is "standardization". I am just pushing for it, and I think it has its own rationale.
Well, the A-frame on Hunts can, hopefully, still manage one (instead of the two ARCIMs) http://navyrecognition.com/images/stori ... Navy_3.jpgSW1 wrote: the current one is MAST-13 which is 13m long too big for type 26
and whatever number of USVs are released, they are the screen: a helo from the frigate can prosecute a fleeting/ fleeing contact that the 'screen' came into contact withSW1 wrote: The frigate may be the asset that processes the data and monitors the systems and acts on the information.
If a bit more use was made of the under flight deck space then maybe it would be possible to do both.Aethulwulf wrote:So do they choose one capability, but loose another?
Thats logical but the correct capability must be established first. Only then can the standardised dimensions follow.donald_of_tokyo wrote:"The same size" = standardization is the key.
Obviously no 'command wires' but is it ideal to have either end of the system so far apart?SW1 wrote:Well there sure as heck split when the off board system is deployed! There certainly not connected by command wire.
There designed to be completely separate that’s the whole point. Operator in one place boat in another. Operator in room somewhere boat tied up at harbour, iso container in Nevada uav over Iraq.Poiuytrewq wrote:Obviously no 'command wires' but is it ideal to have either end of the system so far apart?
The Leander design did things very differently with a space reserved in the misson area big enough for an ISO. This space was directly adjacent to the davit and below a hatch in the deck head. A 16 ton deck mounted crane could load and unload the command module through the hatch if necessary ensuring that systems could be transferred from other vessels if necessary.
The Iver Huitfeldt's have a crane, as does some of the A140 models.SW1 wrote:The only benefit I see is Leander had a crane.
Leander like boat bay configuration loses nothing. Sometimes 4 RHIBs, sometimes 2 and 2 11-m USVs.Aethulwulf wrote:I did not say there is zero chance of adding USV based ASW capability to T31.donald_of_tokyo wrote:There is zero chance of adding USV based ASW capability to T31, as you say.
As this is future ASW thread, and many here (including me) think adding shallow water ASW is meaningful, my proposal comes in.
What I said is that if the RN wanted to alter the design of T31 to have 2 large boat bays (to match the T26 size) and 2 small boat bays they could, probably at almost zero cost. We will have to wait to see the final design to know if they go for this.
But if they do, the T31 would no longer be able to support four Pacific 28 RHIBs. There is an assessment that this is the number required for certain maritime interdiction tasks.
So do they choose one capability, but loose another? I don't know.
And, Leander design included ARCIMS USV, but Arrowhead 140 did not. And looks like ARCIMS-like sized USV is considered in T26 as well.SW1 wrote:All we have to go on so far for the ship is this statement “ Four large dedicated Boat Bays with flexible launch and recovery capability to operate a variety of different offboard assets, such as RHIBs, Unmanned Underwater Vehicles (UUVs) and Unmanned Surface Vehicles (USVs); able to deliver a range of roles from interdiction missions to Special Forces operations and littoral manoeuvre exploitation.”
Then, it means T26 mission bay is too large?The beauty of a reconfigurable ship design as pioneered by the Danes is that it can be changes to suit changing circumstances. But future asw is more than simply what fits in a boat bay. Traditional frigates may not be the optimal vessels to carry and deploy such systems. The frigate may be the asset that processes the data and monitors the systems and acts on the information.
The equipment & its install has fixed prices (well near enough), but hull quietening cost all depends on how quiet you want to go. I suppose the high end would be converting to hybrid diesel electric/direct diesel drive, rafting everything, isolating noise makers from hull, reducing hull extrusions, selected active noise suppressors & a bubble screening. Low end could just be rafting two of the four diesels for low speed and isolating just the minimum of kit and rely on turning off the rest. Hard to cost but traditionally, ASW escorts have been 25% higher.PAUL MARSAY wrote:what would it take for the A140 to become the fleet ASW escort ? Basically HMS, Captas4 and hull quieting. Could it be done for 400m ?
They clearly have the right idea. Keeping good systems in there.shark bait wrote:Or take the French approach, do none of that and buy a really good off-board sonar.
A while back when the FTI was in it's infancy the designers had to make a decision, a high performance hull, or a high performance sonar, doing both was deemed unaffordable. They have opted for the latter.
I think this is an interesting one; is there much value turning the T31 into a slightly smaller T26? Or should the navy aim to tackle the sub hunter issue from a different angle?
If the RN / MOD are really thinking of building 8 type 31 then maybe they should split the build into 2 batches of 4 the first batch built as is with a HMS the second go a little bit more and raft one engine room and fit a CAPTAS-4. We know A-140 can make 18 knots on one engine 25 knots on two and 30 knots on four so rafting one engine room would be good enoughshark bait wrote:Or take the French approach, do none of that and buy a really good off-board sonar.
A while back when the FTI was in it's infancy the designers had to make a decision, a high performance hull, or a high performance sonar, doing both was deemed unaffordable. They have opted for the latter.
I think this is an interesting one; is there much value turning the T31 into a slightly smaller T26? Or should the navy aim to tackle the sub hunter issue from a different angle?