Current & Future Escorts - General Discussion

[Aethulwulf]

Just noticed that in the attached diagram of Absalon and Iver Huitfeldt class, the Merlin in the hanger does not have its tail folded.

I guess the Danish Merlins don't have a folding tail.

All the UK Merlins do have folding tails. Does anyone know how much extra space this will free up within the hanger?

[donald_of_tokyo]

Merlin_Dimensions.JPG

aw101-helicopter-folded.png

19.95 m vs 15.75 m in length
6.62 m vs 5.30 m in hight.

[Aethulwulf]

Thank you.

If would appear that the hanger is large enough to take a V22 Osprey, when folded.

V22 Osprey
Folded length 63 ft (19.2 m)
Folded width 18 ft 5 in (5.61 m)
Folded height 18 ft 3 in (5.56 m)

If the SF ever get their wish to have a few V22s, this could make the T31 an extremely useful asset.

(Deck might need strengthening to take the extra weight.)

[benny14]

Niels Juel in Baltops this week. Working along side HMS Monmouth, HMS Ramsey and 7 RN Archer-class vessels (HMS Dasher, Example, Explorer, Express, Puncher, Pursuer and Trumpeter)

[Caribbean]

You have my full apology for misunderstanding your post.

Hansomly put I overlooked the fact that sarcasm doesn't come over too well in the written word (and I apologise in turn for that), so guessed that you'd just read the first bit and hit the "outrage" button (never done that myself, of course, honestly, no, never....... well maybe once , or twice .... ).

I think we are on the same page about the IH. It's built to DNV Naval standards where it matters and has been through sufficient testing to ensure that it performs pretty well. Nothing in the current standards toolbox is likely to stop a modern, top-end ASM making a real mess of pretty much anything that it actually hits (and I suspect that even the most heavily armoured battleship of yesteryear would have a bit of trouble with the latest hypersonic missiles), but a lot can be done, short of that eventuality, to try to ensure that the ship remains under control, can manoeuvre and hopefully, still fight. If all that fails, then the hull should, at least, remain buoyant long enough to allow evacuation.

[abc123]

You have my full apology for misunderstanding your post.

Hansomly put I overlooked the fact that sarcasm doesn't come over too well in the written word (and I apologise in turn for that), so guessed that you'd just read the first bit and hit the "outrage" button (never done that myself, of course, honestly, no, never....... well maybe once , or twice .... ).

I think we are on the same page about the IH. It's built to DNV Naval standards where it matters and has been through sufficient testing to ensure that it performs pretty well. Nothing in the current standards toolbox is likely to stop a modern, top-end ASM making a real mess of pretty much anything that it actually hits (and I suspect that even the most heavily armoured battleship of yesteryear would have a bit of trouble with the latest hypersonic missiles), but a lot can be done, short of that eventuality, to try to ensure that the ship remains under control, can manoeuvre and hopefully, still fight. If all that fails, then the hull should, at least, remain buoyant long enough to allow evacuation.

Well, I would said that a hit of modern super/hypersonic missile means ( except for largest ships like carriers and similar ) allmost definitly a mission kill, with these other two options something about what you can flip a coin, maybe it will sink and maybe will not- depending mostly about where the ship is hit. That's just my gut feeling, of course.

[Poiuytrewq]

Thank you.

If would appear that the hanger is large enough to take a V22 Osprey, when folded.

V22 Osprey
Folded length 63 ft (19.2 m)
Folded width 18 ft 5 in (5.61 m)
Folded height 18 ft 3 in (5.56 m)

If the SF ever get their wish to have a few V22s, this could make the T31 an extremely useful asset.

(Deck might need strengthening to take the extra weight.)

Its a very generous space for a single hanger.

image.jpg

Even room for a fridge freezer a few bicycles

image.jpg

But still not as big as it could be.

image.jpg

The flight deck is Chinook capable but would need strengthened for the V-22.

[Repulse]

donald_of_tokyo, according to a Defence Minister in 2011 the requirement for a 100% available ASW frigate for TAPS has always been there, even when there were MPAs.

https://publications.parliament.uk/pa/c ... 3297000327

Unfortunately the right set of options is sorry affair is either;
a) Build 2 more full fat T26s. This would both lower the cost per hull and improve investment in more efficient building practices - making the T26 much more attractive for export.
b) Build 1 more T26, plus 5 more upgraded B3 River Sloops to a design that makes them attractive for export.

[Gabriele]

Just noticed that in the attached diagram of Absalon and Iver Huitfeldt class, the Merlin in the hanger does not have its tail folded.

I guess the Danish Merlins don't have a folding tail.

All the UK Merlins do have folding tails. Does anyone know how much extra space this will free up within the hanger?

Indeed no, Denmark only has AW-101 in the troop transport role. Remember that the 6 RAF, now CHF Merlin HC3A were taken urgently up from the danish fleet. They don't have folding tails, but apparently can fold their rotors.

On Absalon:



For the naval role proper they had Lynx and then procured a few Sea Hawks.

[Ron5]

Type 45's noise has been overstated I think. Gabe had the test results on its noise some time back, apparently its not that loud.

The only test results have been for noise within the ship as it relates to crew well being. No external noise characteristics have been published. That would be classified info.

[Poiuytrewq]

What a great photo, a picture tells a thousand words.

Can anyone tell me why the Iver Huitfeldt hanger would be preferable to the Absalon version? It's obviously smaller, lacks the enormous versatility of the double hanger design and it actually looks like it's more expensive to build.

I understand the completely valid points about the single spot flight deck but it isn't necessary to have both helicopters airborne at the same time. Even if the second hanger was only used for ISO/TEU storage or UAV's rather than a second helicopter it must be preferable to the single hanger option.

As its already designed and in use and would effectively slot straight into Arrowhead design surely this would be a useful and inexpensive inclusion into the A140 concept.

Is anyone aware of a reason why the double hanger was not included in the Iver Huitfeldt design apart from accommodating the Smart-L radar?

Has there been any issues with the Double on the Absalons that anyone is aware of? Stability etc?

[Ron5]

Thank you.

If would appear that the hanger is large enough to take a V22 Osprey, when folded.

V22 Osprey
Folded length 63 ft (19.2 m)
Folded width 18 ft 5 in (5.61 m)
Folded height 18 ft 3 in (5.56 m)

If the SF ever get their wish to have a few V22s, this could make the T31 an extremely useful asset.

(Deck might need strengthening to take the extra weight.)

You need to add in service clearances too. And I believe that rules out the V-22 from the current Type 23 size Merlin hangars. I don't know the size of the Type 26 hangar. And of course the flying deck would have to be larger. I believe that the Chinook capable Type 26 deck allows that.

[Ron5]

or even better add CAPTAS4CI to T45.

That would be just about the biggest waste of money the RN could manage. It's a noisy ship that will never be in the right place to operate a big variable depth sonar effectively.

Could the Leander (or indeed any other ship with a similar set up) operating on it's electrics at slow speed (7-8 knots) with a tail meaningfully contribute to delousing and protecting CASD?

No good protecting a carrier moving at 20+knots.

Sorry, to clarify, I meant delousing in terms of protecting the CASD. What I'm asking about generally, is what use would a slow moving Leander be with a tail? What deployments it tasks could it undertake that would free up a T26?

The original question (would a quiet Leander with a tail be useful) is a good one. I'm not sure anyone here can give a great answer.

I would have thought as part of a Type 26 led group hunting for submarines, it would have value but I don't know how much.

I do know operating a long tail while performing close in escort for a carrier group is a no no. Those tails get pretty long and greatly impede the towing ships maneuverability. So everyone else would have to keep well clear. Which kinda defeats the objective of close in defense.

[Ron5]

You need a lot more than 1" of armour to stop even a 250lb bomb let alone a current generation mach3+ ASM. The shock damage alone would wreck the vessel hit even before we get to rupturing the hull. To be effective against possible threats we would have to add at least four times as much. Yes sufficient armour would mitigate some damage, which is why the USN brought back the Iowas in the 1980s and introduced Kevlar on many of its vessels to stoop splinters and small calibre rounds. It was thought the BBs could shrug off hits form the heavy Russian ASMs, get into gunnery range and blow a Kirov, for example to hell and back. As it stands, no escort can expect to survive a hit from a current generation Russian or Chinese high speed, heavy ASM or a heavy Torpedo. The impact, shock and explosive damage would leave the vessels simply trying to stay afloat long enough for the crew to get off.

I do get the point regarding steel that is too thin being used on current naval vessels. I am sure some very well paid people have done a risk assessment based on dubious data and concluded there is no risk to a vessels constructed using such materials with no thought to saving weight or money in a given design.

Thanks for input to my original post, must emphasise that as said the use of thicker steel plate in build of frigates/destroyers would in no way stop a 250lb bomb or a Brahmas, talked of mitigation several times so as to give ship chance survive and capable of taking damage and continuing to fight from a non fatal strike.

Lets play a very simplistic what if scenario, T26 comes under attack from a Brahmas, Sea Ceptor works as advertised but due to the Mach 2.5 closing speed intercept very close in and when the Brahmas breaks up the propellant tank with its massive kinetic energy breaks through hull and ends in cabin as a massive fireball. Internal build using 4mm thin steel plate and though the highly sophisticated damage control activates with its highly pressurized water sprinkler system to spray atomized demineralized water with its limited supply it is overwhelmed and before the damage control party can get to scene the 4mm steel plate reaches its melt point and fire expands out of control and ship lost. Alternative is that ship uses 16mm steel plate and with four times mass able to survive the vital few extra seconds enabling the damage control party to reach fire and eventually contain it. Above, I don't know the thickness of the Swedish thin steel plate specified for the T26, though have seen 6.5mm quoted for the QE2 flight deck and 4mm used in commercial world for the giant hotel cruisers superstructures, so don't think figures will be far off.

You would have hoped but very much doubt that the MOD had built half a dozen or so samples of T26 build structure in various thicknesses sizes and types of steel plate and on test range exploded 250lb bombs and rocket engines to determine which has the best survivability after trade off for cost and viability.

My contention being post WWII with the demise of big guns the free lunch of thin plated steel warships and no armour as an acceptable risk is over, though bombs never went away, soft kill mostly negated the ASM, the balance of power is changing with AI homing heads of ASM as LRASM and USN recently funding an additional $119M for a new homing head for Tomahawk ASM and sure Chinese and Russian will have equivalent, negating soft kill making ships more vulnerable.

For goodness sake go and do some research and find out why naval ships are built the way they are. Both your assumptions and conclusions are way wrong.

[Ron5]

Thank you.

If would appear that the hanger is large enough to take a V22 Osprey, when folded.

V22 Osprey
Folded length 63 ft (19.2 m)
Folded width 18 ft 5 in (5.61 m)
Folded height 18 ft 3 in (5.56 m)

If the SF ever get their wish to have a few V22s, this could make the T31 an extremely useful asset.

(Deck might need strengthening to take the extra weight.)

Its a very generous space for a single hanger.

image.jpg

Even room for a fridge freezer a few bicycles

image.jpg

But still not as big as it could be.

image.jpg

The flight deck is Chinook capable but would need strengthened for the V-22.

Judging by the cleanliness, neatness and complete absence of any spare parts or maintenance equipment. I would say both these hangars are not used for operating helicopters.

[donald_of_tokyo]

donald_of_tokyo, according to a Defence Minister in 2011 the requirement for a 100% available ASW frigate for TAPS has always been there, even when there were MPAs.

https://publications.parliament.uk/pa/c ... 3297000327

Unfortunately the right set of options is sorry affair is either;
a) Build 2 more full fat T26s. This would both lower the cost per hull and improve investment in more efficient building practices - making the T26 much more attractive for export.
b) Build 1 more T26, plus 5 more upgraded B3 River Sloops to a design that makes them attractive for export.

Thanks. So, MPA was/will be doing what task, and now it is covered by who? In other word, regaining MPA capability will release what tension in the fleet?

ASW is a system. We can easily say capability A cannot replace B. But, as a system, INCREASING capability in A can, in many cases, relax B.

I think increasing MPA number can help ASW frigate. Also I think 9 is not enough an make MPA inefficient. Making it 12 or 13 will increase the overall efficiency and hence will be a good buy?

By the way, your option (b) is my favourite, and (a) is also one of my dream. But, one more T26 may amount to 4 or 5 more P8As, making the fleet 13 or 15. It is worth considering I think.

[Tempest414]

What a great photo, a picture tells a thousand words.

Can anyone tell me why the Iver Huitfeldt hanger would be preferable to the Absalon version? It's obviously smaller, lacks the enormous versatility of the double hanger design and it actually looks like it's more expensive to build.

I understand the completely valid points about the single spot flight deck but it isn't necessary to have both helicopters airborne at the same time. Even if the second hanger was only used for ISO/TEU storage or UAV's rather than a second helicopter it must be preferable to the single hanger option.

As its already designed and in use and would effectively slot straight into Arrowhead design surely this would be a useful and inexpensive inclusion into the A140 concept.

Is anyone aware of a reason why the double hanger was not included in the Iver Huitfeldt design apart from accommodating the Smart-L radar?

Has there been any issues with the Double on the Absalons that anyone is aware of? Stability etc?

I would agree that for A140 to be the best it can be for the RN it needs to take the best from each sub class of the design. to this end for me the best it could be is

take the Iver Huitfeldt main design and fit the double hangar from the Absalon next remove the stanflex mission deck and add a mission bay amidships between the front boat houses armament fit a 5 inch main gun 9 cell ExLS in between the bridge and gun on top of the mission bay fit 8 RBS-15 Mk-3 and on top of the hangar fit a phalanx for me this gives the ship maximum capability and flexibility with the mission bay, twin hangar and storage under the flight deck it gives the ship good mission space and the armament gives good self defence and ship and land attack out to 200 km

[NickC]

To me the main drawback to IH is the noisy CODAD propulsion, not a concern for the Danish Navy as it is an AAW ship.

You can go the full fat as the FREMM and Type 26 with shaft mounted electric motors, no noisy MGR and Diesel Gensets on double resilient mountings within sound enclosures - costly, or half way house as with the new Italian 6,000T PPA Fincantieri frigates where two of its four MAN 12V175D 1,640 kW GenSets, are silenced to power electric motors via MGR at low speeds for ASW ops.

As always question of how to keep T31 within the £250M cost cap, may be one possible option to partially alleviate the IH noise comes from an ASNE paper by Fincantieri on the Abu Dahbi corvette which is kitted out with Kingklip HMS and CAPTAS 2 VDS.

"The solution defined in the simulation study for the propulsion train, led to installing the propulsion engines upon resilient mounts – single stage – with proper associated rigidity. The reduction gears are rigidly mounted on foundations carefully treated by means of appropriate visco-elastic materials and doubling plates, aimed to dampen frequencies considered critical to the sonar’s performance. 

The more classic alternative would have been to install the engines and reduction gears upon a first stage of resilient mounts on a common base, coupled to the ship’s lower hull by means of a second stage of resilient mount. 

This alternative would have cost more, been more difficult to implement in the ship and decreased maintenance space access for workers."

Question arises does the RN want an IH T31 as it might well threaten the future of the T26, if IH selected might not Treasury think why are paying £1B for the Type 26, when it could fund two or more upgraded silenced IH for £1B, not beyond possibility that the T26 will be cancelled after first buy of three.

For info the flex container as so successfully used on Danish Navy ships including IH, the hyped USN LCS swappable mission modules are now history.

[donald_of_tokyo]

Good thing (I think) about Arrowhead 140 is that, it's cost is really tight and it will allow almost zero modification. This will NEVER allow so called "mission creep". This is very important, to reduce the building risk for Babcock. No more mess. Adopting IH-class design is already very "tight".

[abc123]

You need a lot more than 1" of armour to stop even a 250lb bomb let alone a current generation mach3+ ASM. The shock damage alone would wreck the vessel hit even before we get to rupturing the hull. To be effective against possible threats we would have to add at least four times as much. Yes sufficient armour would mitigate some damage, which is why the USN brought back the Iowas in the 1980s and introduced Kevlar on many of its vessels to stoop splinters and small calibre rounds. It was thought the BBs could shrug off hits form the heavy Russian ASMs, get into gunnery range and blow a Kirov, for example to hell and back. As it stands, no escort can expect to survive a hit from a current generation Russian or Chinese high speed, heavy ASM or a heavy Torpedo. The impact, shock and explosive damage would leave the vessels simply trying to stay afloat long enough for the crew to get off.

I do get the point regarding steel that is too thin being used on current naval vessels. I am sure some very well paid people have done a risk assessment based on dubious data and concluded there is no risk to a vessels constructed using such materials with no thought to saving weight or money in a given design.

Fully agreed.

[Caribbean]

Question arises does the RN want an IH T31 as it might well threaten the future of the T26

That, and the unnecessary cost of re-designing the IH T31 for ASW are why we are extremely unlikely to see anything other than GP variants of the T31 until after the T26 is completed. As it is, the IH can be configured as a Tier 2 AAW and ASuW vessel (at a standard that would be Tier 1 for a lot of navies), without modification. Arguably, outside of CASD and fleet operations, AD is more important than ASW (there are a lot more aircraft and missiles around than submarines), so I would regard it as reasonable to leave Tier 2 ASW (as in URN optimisation and tail) until a later variant. A small amount may have to be done, to allow for FFBNW or FTR requirements, but that is all.

[Poiuytrewq]

I would agree that for A140 to be the best it can be for the RN it needs to take the best from each sub class of the design.

With a fundamental redesign the A140 could be a real cracker but what could be achievable without such a redesign?

Something between simply adding a couple of basic boat bays like Team 31 have proposed and a complete reconfiguration of the superstructure.

I initially proposed moving the starboard funnel and if it was not cost prohibitive I would still do it but if achieving a larger more versatile mission bay is the aim, it's not the only way.

image.jpg

Its clear from the graphic that moving the StanFlex module from the Weapons deck creates a lot of space. It's also clear that housing 16 Mk41 VLS cells (or equivalents) in the StanFlex 'B' position is perfectly possible. Why would a T31 need more than 16 VLS cells especially if 16 Harpoon launchers (or equivalents) fit on the Weapons Deck? Seems like plenty of offensive/ defensive capability even before considering the helicopter(s) for the T31. The Hanger marked in Green is easily Merlin capable with additional areas on either side for extra storage or mission spaces.

The area on the port side could be combined with the hanger to allow a combined hanger/ mission space adding versatility. This graphic illustrates the potential.

image.jpg

The main mission area that could be created amidships is vast, easily capable of housing 3 CB90's, store 8 to 10 ISO's or a large amount of bulky mcm equipment. These fairly simple alterations would make the A140 a true multipurpose vessel.

Good thing (I think) about Arrowhead 140 is that, it's cost is really tight and it will allow almost zero modification. This will NEVER allow so called "mission creep". This is very important, to reduce the building risk for Babcock. No more mess. Adopting IH-class design is already very "tight".

Is it possible for £250m?, I still don't think that's clear. All of the published figures do not support this vessel being constructed in the UK for £250m. I think it's inevitable that if the A140 is adopted for RN service it will be modified to suit RN requirements.

Question arises does the RN want an IH T31 as it might well threaten the future of the T26

That, and the unnecessary cost of re-designing the IH T31 for ASW are why we are extremely unlikely to see anything other than GP variants of the T31 until after the T26 is completed.

You may be right but given that we are into the 3rd defence review in 8 years a lot could happen between now and then. Is it conceivable that we could have another 3 reviews before the first T26 enters service?

The question of why the FTI with its Captas 4 compact towed array can be built for hundreds of millions cheaper than a T26 will not go away. We all know the ASW performance will be inferior but that £8bn budget (£4.3bn remaining) is an extremely tempting political target.

What's to stop Team31 developing an ASW variant anyway. If the A140 wins the T31 competition could the profits be reinvested back into designing even more capable variants? From an export perspective, the ASW capabilities of the Iver Huitfeldt class has always counted against it and I suspect Team31 will be looking to remedy that in the future.

With all the focus on the A140's, is it possible BAE/Cammell Laird could slip under the radar with upgraded Leander with a basic ASW capability. It must be obvious to BAE/CL that the best way be beat the A140 design is too introduce a useful ASW capability into the design.

[donald_of_tokyo]

Good thing (I think) about Arrowhead 140 is that, it's cost is really tight and it will allow almost zero modification. This will NEVER allow so called "mission creep". This is very important, to reduce the building risk for Babcock. No more mess. Adopting IH-class design is already very "tight".

Is it possible for £250m?, I still don't think that's clear. All of the published figures do not support this vessel being constructed in the UK for £250m. I think it's inevitable that if the A140 is adopted for RN service it will be modified to suit RN requirements.

Arrowhead 140 completely meets RN requirement, written in T31e RFI. There is zero need for further modification. The prototypical "mission creep" has just started because Arrowhead 140 is large and "looks" capable.

[Poiuytrewq]

Arrowhead 140 completely meets RN requirement, written in T31e RFI. There is zero need for further modification. The prototypical "mission creep" has just started because Arrowhead 140 is large and "looks" capable.

Agreed, I think the design is actually a bit more than expected in the RFI, certainly the displacement is considerably larger.

Maybe the solution to offer the basic Frigate at £250m and then have a list of fully costed options so RN can make an informed decision at the time of ordering?

No extra money, the basic design will have to do.

[benny14]

Maybe the solution to offer the basic Frigate at £250m and then have a list of fully costed options so RN can make an informed decision at the time of ordering?

Re-desiging the ship as you propose will be expensive. The current design meets the requirements. By all means provide them with options, but the goal should be to make it fit the bill, not exceed it by a mile.