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Mine countermeasures and Hydrographic capability (MHC) (MHPC)

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Poiuytrewq » 12 May 2018, 10:39

Repulse wrote:However, I do not see the need to build a fleet of large ships specifically to operate half a dozen MHC USV/UUVs, it will never be more than this number so what is the point.
I think it depends on how they are going to operate. For example, if one MHC vessel that is capable of defending itself in moderate threat areas without escort, replaces 2 or 3 MCMV'S and a BAY it will need to be a pretty large ship.

If that large MHC vessel was fitted with a 57mm, 2x 30mm's and Phalanx FFBNW, had a crew allocation of 60 to 70 and also posess the ability to embark 2 wildcats or a Merlin if necessary it is worth considering in my view. Especially if it could be built for £100m to £125m.

If the MHC vessels are still going to operate as a small group with an attending mothership then I agree, exceeding about 3000t is probably unnecessary

Tempest414 wrote:....global multi purpose patrol vessel = type 31 in its current form.
In my opinion this is the reason the T31 is on the wrong track. I can see no reason why a multipurpose globally deployed patrol vessel deploying to low threat environments needs to cost in excess of £250m and have a crew allocation of 100. These Multipurpose OPV's should be contructed to RB2 build standards, be capable of 25knts, embark a helicopter and have lots of space for ISO's and HADR equipment. If designed properly they should be able to relieve the Bay in the Caibbean.

These vessels would be a great area for RN to save money.

Is a River Batch 3 the right way to go?

Should the next generation of RN OPV's be built on the Khareef hull, a bit like a shortened Leander?

Whatever it ends up being it should be simple and cheap and any extra funds should be used to make the T31's proper Frigates.

donald_of_tokyo wrote: They just stop thinking, waiting for some miracle to happen, and failed.
Exactly, waiting for HMG to fix the problem with more money. This is one of the procurement areas that really needs to change.

donald_of_tokyo wrote: If HMG/RN decided to shft to 8 T26 + 5 T31e program already on 2014, the ~650M GBP spent on River B2 should have been added to the 1.25B GBP T31e program cost, making it 1.9B GBP
That would have been a great result. In my opinion £1.9bn is just about the magic number for the T31 programme but of course extra money would of had to have been found for the EEZ patrol vessels. I think the RB2 procurement saga proves that it is not always about more money, it is also about making the best use of the money available.

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Caribbean » 12 May 2018, 12:19

@Repulse - indeed, keeping to a single tier 1 frigate design and a single sloop design (or rather a range of designs based around a common core) would have been a very sensible way to go.

However, for all the reasons discussed on this and other threads we are now in the position where the "range of designs based around a common core" seems to be the objective of the T31 project (and potentially the T26 in the future), with the Rivers being side-lined (BAE could win the competition, of course, but their offering seems the least enticing at the moment).

Which leaves the MHC program somewhat in limbo, since there is no (as yet) clear candidate for a base design.

My personal feeling is that it will end up being rolled-up into the T31 program, if that proves to be successful, since there will be spare industrial capacity after building the initial 5 (even if a second batch of 3 ASW variants were tacked on, using the last T23 2087s). On a 12-15 year build cycle, there would be room for another 4 to 7 hulls before the replacements for the first batch are started on. Whether it uses the T31 hull as-is, uses common hull modules with (say) a different stern and superstructure, or even is built to a totally different design (in which case it would get a new designation, I would assume), I don't know, but I suspect that the same industrial mechanisms will be used.

Why do I think they will be a T31 variant and not a stand-alone design? Two specific points stood out for me in the discussion above - firstly, that the off-board MCM systems are actually quite bulky, which may necessitate the use of larger vessels as hosts. The second was "do we really need a new design specifically for the role"? Both these issues could be addressed by adapting the T31 hull, as it is big enough to host these new systems and only parts of the ship would need to be re-designed for the new role.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Poiuytrewq » 12 May 2018, 20:31

Caribbean wrote:.....we are now in the position where the "range of designs based around a common core" seems to be the objective of the T31 project

....these issues could be addressed by adapting the T31 hull, as it is big enough to host these new systems and only parts of the ship would need to be re-designed for the new role.
Combining the MHC, Patrol and Light Frigate programmes by using a single hull form would be the commonality Holy Grail. I looked at this a while ago but getting the crew allocation down to between 50 and 70 seemed to be difficult for the MHC and Patrol Variants.

Of all the available options the Absalon hull is probably the most likely candidate, if you are looking for multipurpose versatility it has it all.

image.jpg
At 137m the Absalon hull is pretty big but there is an obvious central block in the superstructure that could be removed.

image.jpg
The detailed drawing shows this middle block contains the weapons deck and the forward area of the flex deck. To remove this 20m section looks simple enough. The flex deck would lose 20m, the forward engine room would push into the accommodation and cold storage area. It's all seems perfectly doable, in fact at 117m, this configuration would be a great starting point for the T31. The required CAMM cells could replace the secondary armament between the main gun and the bridge and loss of accommodation would be offset by the reduction in crew numbers.

For the Patrol and MHC variants a length of around 100m is probably optimum if an embarked aviation capability is to be retained but the 19.5m beam is far from ideal for speed and economy but would undoubtably help stability as the hull is shortened.

image.jpg
The least complicated way to shorten the hull would be to remove the hangers but it would be a shame to remove such a useful multipurpose space. Ample room for two Merlin's in there. It's lucky that steel is cheap and the air is free :D

image.jpg
Is it possible to lose another 17meters?

Probably, but not without a significant redesign. Due to the size of the flight deck it could probably be shortened by 4m or 5m and the hanger could be pushed forward another 10m or 12m into the main superstructure under the combat information centre. This would produce a 100m vessel with a 19.5m beam in the region of 3500t to 4000t. It would have a 57mm main armament, twin hanger, a 40m to 50m flex deck and space for CAMM and Phalanx if required. Possibly a bit extreme for an OPV but a respectable size for MHC in my opinion.

image.jpg
The Svalbard has a similar configuration at 103m long, 19m beam, can embark 2 wildcats and has a 57mm main armament but is significantly heavier at 6500t. With a 40m to 50m flex deck, would a 100m Absalon variant be even more versatile for mcm operations than the Svalbard?

So in an Absalon variant, how would the mcm craft be deployed?

Is the stern mounted crane essential?

Due to the level of the flex deck above the water line it's hard to see how the stern of an Absalon variant could be configured like the Harry DeWolf below.
image.jpg
The stern arrangement on the Harry DeWolf looks extremely useful with the 20t crane and double height covered working deck under the flight deck but would the rear doors on the Absalon be just as efficient at deploying mcm craft as a stern mounted crane or the davits on the Venari 85?
image.jpg
The stern door on the port side of the Absalon hull has a monorail and crane system able to deploy various craft but options are limited and and due to the weight limit this system lacks the versatility of a stern mounted crane. Is a 9.4t safe working limit enough for mcm operations?
image.jpg
Would the addition of a side door and a 25t monorail and crane system future proof the vessel for mcm operations? This would vastly increase the range of off board systems that could be launched as well as small LCVP's or CB90 fast assault boats.

The 19.5m beam would greatly aid stability for side launching in less than ideal sea conditions and this additional capability would make the most of the flex deck on both the 117m and 100m variants and turn them into true multipurpose vessels.
image.jpg
Trying to get 3 classes of vessel out of a single hull form is asking a lot but if something similar to the Absalon is chosen for the T31 it looks to be at least plausible that an MHC variant could share the T31 hull.

A 100m Patrol version looks unlikely not because the design wouldn't work necessarily but mainly because getting the 19.5 beam to achieve 25 knots would be cost prohibitive.

IF and it's a big IF it was possible to get a 100m Absalon variant with a 57mm, twin hanger, a 40m to 50m flex deck with the option if required of CAMM and Phalanx to achieve 25knts together with a reasonable crew allocation and all for a sensible build cost they would sell so fast that British shipyards would be unable to keep up with demand :lol: (and I suspect someone else would have done it before now)

But back to reality. My main concern apart from the initial build cost remains the crew allocation but I think it's fair to say if RN wanted to do something radical this may be a very good place to start.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Repulse » 13 May 2018, 00:00

If the RN didn't want to evolve the River design then my vote is to start with the Venator 90 (extended by 10-20m)

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby ArmChairCivvy » 13 May 2018, 04:12

Poiuytrewq wrote: getting the crew allocation down to between 50 and 70 seemed to be difficult for the MHC and Patrol Variants.

Poiuytrewq wrote:My main concern apart from the initial build cost remains the crew allocation but I think it's fair to say if RN wanted to do something radical this may be a very good place to start.


Thanks for the thought-provoking piece. I agree that Harry deWolf arrangement would be great for the second (MHC) variant.
- why would the crewing, in the patrol variant, be much higher than in the Hollands? They went up from the planned 32 to three dozen and with the helo mission crew the total is touching 50.
- add to that the MCM mission crew... and at times a RM protection party (on the patrol variants that might be the non-compliant boarding party) and then we start to approach your quoted numbers?

The three versions out of one hull is the way to go, if there is to be any hope of stopping the decline (not in tonnage, but) in hull numbers of the RN. Not something unique: The infamous LCS came about largely as a result of the withdrawal of the Oliver Hazard Perry-class frigates that were the smallest ocean-going combat vessels of the US Navy Quess what: this lead to an increased demand for the Arleigh Burke "work horse" destroyers. For a number of missions these high-tech (read: expensive) destroyers are overkill, and a smaller (i.e. cutting the manning "afloat" for the mission duration) "package" had to be found for flag waving and patrol missions where asymmetric threats rather than fleet-on-fleet engagements are the reality. In their original spec the LCS may look like full-blown corvettes or light frigates, despite in fact being large patrol ships (especially after the NLOS-based capability to project onto land, in support of SF/ recce parties landed for a short duration was lost).

Starting to sound familiar? The Congressional Research Service, CRS, summarised in April this year - when the addition to the mix from patrol ships had been adjusted in favour of "propper" frigates... that's how the pendulum swings:
"Although the 355-ship force-level goal is 47 ships higher than the previous 308-ship force-level
goal, achieving and maintaining the 355-ship fleet within 30 years would require adding more than 47 ships to the Navy’s previous (FY2017) 30-year shipbuilding plan, in part because that [earlier] plan did not include enough ships to fully achieve all elements of the 308-ship force-level goal. CRS estimated in 2017 that 57 to 67 ships would need to be added to the Navy’s FY2017 30-year shipbuilding plan to achieve the Navy’s 355-ship fleet
- I like the approach: for ship numbers they do not add fractions to the wrong side of the decimal point, but rather count in tens.
- when you plan for 30 years (or 40, if you apply alternative assumptions to service lives of various types) that suits the purpose... OK, we are aiming to do "fives" but the again there is the difference in scale.

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby donald_of_tokyo » 13 May 2018, 13:00

I do not think common hull is so important. If they are cheap hulls, its design cost is also small. Building ships with hull design specific to their tasks will be more important.

Yes, MHC is an idea to unify MCMV and Hydrographic ships design. But I think this means, operation of MCMV drone kits is "not much different from" hydrographic and survey tasks. No need for high speed, bulky hull and low-level deck, with 15-25t crane is what is needed. Also, hydrographic and survey ship needs to self deploy, and MCMV was newly added with this requirement.

But, this does not mean it must be the same design to T31e. No need for 25+ knot speed in MHC, no need for CAMM or gun on MHC, and no need for high-level mine hunting data analysis, and no need for wide-band-width data-link systems with ROV for T31e (but yes, low level MCM systems may be no problem).

Make them common ONLY IF their requirement it very similar, and I think T31e in current form (RFI) and MHC will have many different requirement sets.

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Caribbean » 13 May 2018, 16:29

donald_of_tokyo wrote:this does not mean it must be the same design to T31e

I don't think that is what we are necessarily contemplating. Personally, I certainly meant that we should be looking at assembling ships from common "component blocks", so that, for instance, two different variants might have (as an example) common bow and amidships hull and superstructure sections, but different aft superstructure blocks and stern. This reduces additional design effort to the affected blocks only. Building in maximum flexibility in a specific variant, though, might enable it to undertake the duties of another variant, though undoubtedly less efficiently than a purpose-built variant.

Though I didn't initially think that an Absolon-derived vessel would be the likely outcome of OMT joining the team (I thought that it's more likely that they were looking for solutions to specific design issues, rather than overall design philosophy), I must admit that I like the concept - the "flex deck" seems to live up to it's name.

@Poiuytrewq - interesting stuff, above. I does look as if a c. 120m version is quite possible. On the Patrol side, I would suggest that it's probably not necessary to try to shrink the design down to 100m as you discussed. BMT concluded in a study, that 103m was the minimum if you wanted to maintain self-deployability in all conditions, so 103-105m would seem the minimum desirable. HNLMS Holland is c. 108m, for instance. If you couple that with reducing the beam slightly as well (for all variants), could we arrive at a design that could maintain 25kts without huge expenditure? Alternatively, your patrol variant could simply use the 120m hull, but with more focus of HADR, medical facilities and patrol/ work boats as the "offboard systems".
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby shark bait » 14 May 2018, 16:39

Repulse wrote:As such we should expect these systems to be operated from Frigates, Sloops and RFAs - so in that respect we are all correct.

However, I do not see the need to build a fleet of large ships specifically to operate half a dozen MHC USV/UUVs


Because it is stupid to use such specialist vessels for such a simple task.

The RN only have just enough frigates and auxiliary's to do its job. Burdening them with the job of operating mine clearance boats, will only further reduce the number of frigates available for combat.

Replacing 15 minehunters with 3 more crap gun boats does nothing to help the RN.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Tempest414 » 14 May 2018, 19:13

I would agree we need 12 to 15 ships built to do the job which will allow the escorts to do there job

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Repulse » 14 May 2018, 21:33

shark bait wrote:Because it is stupid to use such specialist vessels for such a simple task.

The RN only have just enough frigates and auxiliary's to do its job. Burdening them with the job of operating mine clearance boats, will only further reduce the number of frigates available for combat.

Replacing 15 minehunters with 3 more crap gun boats does nothing to help the RN.


A completely useless class of large sitting duck decoy vessels is utter madness. You are also misunderstanding my comment, I see 30+ platforms being able to operate MHC USV/UUVs (T26s, River Sloops + RFAs)
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby shark bait » 15 May 2018, 07:40

It's not a large sitting duck. It's a utility platform for mine clearance and survey. It's not for combat.

The more complex these vessels become, the less the RN will get which transfers the burden to the escort fleet.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Timmymagic » 15 May 2018, 07:53

Repulse wrote:If the RN didn't want to evolve the River design then my vote is to start with the Venator 90 (extended by 10-20m)


As time goes on the FSC work seems more and more valid.

Maybe the solution for a few issues is just to go to BMT.

Venator 110 for Type 31
Venator 90 to replace the Hunts
Venari 85 to replace the Sandowns

Oh and a couple of Vidar SSK's please on the side...

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Repulse » 15 May 2018, 13:28

Timmymagic wrote:
Repulse wrote:If the RN didn't want to evolve the River design then my vote is to start with the Venator 90 (extended by 10-20m)


As time goes on the FSC work seems more and more valid.

Maybe the solution for a few issues is just to go to BMT.

Venator 110 for Type 31
Venator 90 to replace the Hunts
Venari 85 to replace the Sandowns

Oh and a couple of Vidar SSK's please on the side...


Or a Venator 110 Sloop (in the form of an extended Venator 90) for all 3 :)

More SSNs and T26s on top as well....
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Repulse » 15 May 2018, 13:32

shark bait wrote:It's not a large sitting duck. It's a utility platform for mine clearance and survey. It's not for combat.

The more complex these vessels become, the less the RN will get which transfers the burden to the escort fleet.


Unless we are talking about sweeping a benign area then it either needs to be a "warship" or be escorted by one. That's the problem, there isn't enough warships to do the escorting so the platforms themselves need to be able to have a risk based level of self protection. It's the same argument as the amphibs.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby shark bait » 15 May 2018, 13:41

That's exactly what we are talking about.

Survey and mine clearance will always be required in none combat environments. That will cover 90% of the work, to burden the combatant fleet with that base-load is a huge waste of rare platforms.

The other 10% can use the mission bays.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Repulse » 15 May 2018, 20:38

shark bait wrote:That will cover 90% of the work.


Really - how do you get to this conclusion?

I have no problem with chartering civilian ships for the peacetime stuff, but do not kid yourself that the RN needs to buy or operate them. Get Secro to do it. But even then please explain how it would work in somewhere like the Gulf if the Iranian Revolutionary Guard wanted to make a point for example?
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby shark bait » 15 May 2018, 21:16

Based on the last 50 years of mine clearance and hydrography operations. It does not tend to happen whilst under fire, unless you would like to provide instances where that is routine?

Truth is, the base load of mine clearance and survey work has occurred in permissive environments.

Fantasising about Iran provides little justification to replace the mine hunters with gun boats.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Poiuytrewq » 17 May 2018, 21:56

ArmChairCivvy wrote:- why would the crewing, in the patrol variant, be much higher than in the Hollands?
My concern is mainly with damage control, the Absalon hull is vastly bigger than the Holland class.
image.jpg
The Holland class is great example of what an OPV can be and is often compared to our very own RB2's. At 3750t, almost twice the displacement of the RB2's I'm not sure it's a fair comparison although they are undoubtably much more capable in the global patrol role mainly due to the embarked helicopter. With a 16m beam the Hollands are 2.5m wider than the RB2's and at 108m, a full 18m longer.

Game, set and match to the Hollands then. Not quite, their top speed is a mere 21.5knts, that doesn't compare well to the RB2's 25knts. The Holland class make up for this lack of speed with the FRISC rigid inflatables which are capable of 40knts and can be deployed quickly whilst still underway via the stern ramp. When combined with the embarked helicopter it all makes for a potent patrol package for low threat level environments. (Note, 76mm main armament and 30mm secondary)

In the HADR role however the Hollands are much more limited, a small number of ISO containers can be stored under the flight deck and although the deck mounted crane is a great addition, due to the lack of storage space it's unlikely to have much to unload unless the small craft or the helicopter is not carried (Note, the ISO and pallet sized deck hatches are clearly visible in the graphic)

So is 25knts really necessary for the 'Patrol' role?

Could an MHC vessel with a top speed of 21knts also perform well in the patrol role if it carried high speed rigid inflatables and embarked a helicopter?
donald_of_tokyo wrote:I do not think common hull is so important......
Building ships with hull design specific to their tasks will be more important.......
Make them common ONLY IF their requirement it very similar......
Personally, I think it's worth exploring, if it was possible to design a common hull form for the T31,MHC and Global Patrol vessels it would undoubtedly save money and may mean more hulls in the water but I agree, it must work for each specific role.

Are the specifications for the 3 variants really that different?

The latest MHC concept, the Venari 85 is pretty wide beamed to ensure stability when deploying the increasingly bulky MCM equipment. Would a vessel with an 18m to 19m beam be suitable for the MHC role, I would say it may even be preferable. The narrow beam of an OPV is one of the reasons BMT uses to suggest that OPV's are less than ideal for the MHC requirement.

So is a 19m beam suitable for the T31?

BMT and Babcock must think so as their Arrowhead 120 concept has a 19m beam.
image.jpg
So if the 19m beam is suitable for the T31 and MHC vessels surely it would be much too wide for the Patrol role?

In the past the answer would be 'much too wide' but looking ahead I'm not so sure.

In my opinion going forward all RN vessels will have to be as multipurpose as possible. For example, why base a Bay in the Carribean when a cheap multipurpose patrol vessel with an embarked helicopter(s) could perform the patrol role more efficiently and also excel in the HADR role if needed with only half the crew allocation. These multipurpose global patrol vessels could patrol and then provide the first response to any humanitarian crisis and thereafter the Bay's could be dispatched if the situation is deemed serious enough to warrant that level of response.

How is it possible to combine all these various requirements in a single hull form?
Caribbean wrote:I certainly meant that we should be looking at assembling ships from common "component blocks", so that, for instance, two different variants might have (as an example) common bow and amidships hull and superstructure sections, but different aft superstructure blocks and stern.
In my opinion the modular construction process opens up a world of possibilities. It's quite simply the only way 3 variants on a single hull form is even remotely possible however unfortunately I don't think the Absalon hull form is suited to a modular construction process. It could easily be built in blocks but if for example a 105m and 120m version was required it would probably lead to a complete redesign of the hull form.
image.jpg
Caribbean wrote:I I would suggest that it's probably not necessary to try to shrink the design down to 100m as you discussed.....103-105m would seem the minimum desirable.........If you couple that with reducing the beam slightly as well (for all variants), could we arrive at a design that could maintain 25kts without huge expenditure?
In my previous post I proposed roughly 100m, within 5m or so. I have been advocating a 105m vessel with embarked helicopter for the MHC programme for a while now so let's proceed on that basis and look at the 105m and 117m to 120m variants.

When shrinking the Absalon by 20m down to 117m it quickly becomes apparent that the tall superstructure is likely to cause problems with stability. As this amount of superstructure is not required for lean crew allocations I have also reduced the height of the bridge and the superstructure aft of the bridge to lower the CoG.

It hard to know how much of a hull redesign would be required for a 117m Absalon without tank testing but on paper it looks pretty good. These images are a pretty rough attempt to illustrate what these shortened Absalon concepts would look like.
image.jpg
image.jpg
With the option of a Mk45 main armament, lots of space for VLS cells forward of the bridge, twin Merlin capable hanger and over 50m of Flex deck what's not to like for the T31. The reduced height of the superstructure helps balance the shorter design and in my opinion this looks like a much better option than any of the current T31 concepts.

The 105m concept is as expected much more problematic. I feel this would definitely require a complete hull redesign but the general concept remains sound.
image.jpg
image.jpg
Although it's clear that at 105m the hull form is all wrong, it's not without its charm :D

The overall configuration of 105m length, 19m beam, twin hanger and 50m of flex deck is clearly viable if built on a suitable hull. This configuration turned out more successful than I initially expected.

So if not the Absalon hull, what else might be suitable?

The Arrowhead 120 hull form looks perfect for the modular construction process but the easiest way to explore the modular 3 variant concept is with the Damen Crossover.
image.jpg
The Damen design adds a welcome bulkhead and divides the Flex deck into 2 separate spaces. This is probably preferable to the simple RoRo Absalon design. The central multipurpose space could be configured in various different ways depending on the deployment whilst the aft amphibious compartment could house the small craft up to the size of LCVP's.
image.jpg
The port and starboard side doors would allow simultaneous deployment of MCM equipment and the deck crane and associated hatches in the flight deck could also aid unloading.

With the modular build design almost anything is possible but the graphics below give an indication of the ease that different variants can be produced with maximum commonality and minimum redesign.

The 105m, 19m beam, 4000t MHC and Patrol variant. Single spot flight deck, twin helicopter hanger.
image.jpg
This looks much better balanced than the Absalon design whilst maintaining the benefits of the flex deck concept.

The 120m, 19m beam, 4600t T31 or Patrol variant. Double spot or Chinook capable flight deck, twin hanger and increased Amphibious capacity. Lots of space for VLS cells forward of the bridge.
image.jpg
In the Patrol configuration, equipped with up to 2 Merlins, 4 LCVP's and vast amounts of HADR supplies, this variant could be a true multipurpose vessel. With up to 2 Wildcats and multiple high speed rigid inflatables these vessels could also excel in the Patrol role.

As an example of how versatile these modular vessels can be, this is the 147m, 5600t Tier 1 Frigate variant. Again lots of space for Mk45, ample VLS cells, 2 landing spots or Chinook capable flight deck, twin Merlin Hanger and over 70m of Flex Deck or multipurpose space. If this hull form and propulsion system was optimised for ASW and combined with 2087 sonar, it could be a very useful multipurpose platform and a good benchmark for any second batch of T31's.
image.jpg
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I am not necessarily advocating the Damen Crossover or the Absalon designs as the basis for the T31 or MH(P)C programmes but the general concept of the modular reconfigurable design is certainly worthy of serious consideration. It is a truly versatile concept especially when designed from the outset to prioritise maximum modularity and commonality across the variants.

Obviously cost is the determining factor but is it possible to produce two different build standards within the same design? For example the Patrol variant to be built to OPV standards with watertight doors and standard bulkheads and the T31 variant to be built to full naval standards with watertight doors and reinforced/blast proof bulkheads. What standard should the MHC vessels be built to?

Until it is confirmed how the MHC vessels will operate in future it is difficult to identify the most suitable design. For example the Op Kipion MCM deployment normally comprises 2x Hunt class, 2x Sandown class and 1x Bay Class. That's over 250 crew and 5 vessels including the Bay.

When the MHC ships enter service will it still be 4 MHC vessels acting with a mothership or will it be 2 or 3 MHC vessels with embarked helicopters acting as a team without a mothership?

If the Kipion MCM deployment evolves into 2 self sufficient 4000t MHC vessels with a combined crew allocation of 120 to 140, fully capable of self defence and even possessing some offensive capabilities via the embarked Wildcats it could prove to be a significant step up in capability as well as provide a long term financial saving for RN.

The Global Patrol Vessels could also be a real game changer for RN, a cost effective patrol vessel designed to provide security in low threat areas that is also fully equipped to provide rapid HADR assistance if required. A true multipurpose vessel.

If the current MCMV's were replaced with 12x MHC/Patrol vessels along with the 5x T31 vessels it would make for a healthy order of 19 ships.

Something like,
8x. 105m MHC variants
4x. 105m Global Patrol variants
5x. 120m T31 variants

A combined 3 variant approach built using modern modular methods of construction could really begin to reverse the decline and may help to Initiate an increase in hull numbers once again. As I have commented previously, if RN wanted to do something radical this would be a very good place to start.
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sunstersun
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby sunstersun » 17 May 2018, 22:39

pump these and sea hunters across the western world.

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby shark bait » 18 May 2018, 08:18

Poiuytrewq wrote:When the MHC ships enter service will it still be 4 MHC vessels acting with a mothership or will it be 2 or 3 MHC vessels with embarked helicopters acting as a team without a mothership?


It's very unlikely to follow the same model.

If the RN confirm remote mine hunting as the preferred route (the french already have), the plan is for the vessels to become self sufficient. I expect at minimum this will be like the Echo class, and may end up becoming a bit bigger with organic aviation support.

I expect we will go from 4 mine hunters and a bay class, down to 2 utility platforms in the gulf.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby shark bait » 18 May 2018, 08:40

Image

Looks like a very nice solution, built off vessels used in the oil and gas industry.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Caribbean » 18 May 2018, 09:33

A ship that is not a frigate?
The pessimist sees difficulty in every opportunity. The optimist sees the opportunity in every difficulty.
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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby ArmChairCivvy » 18 May 2018, 10:11

RSS ES benefits from the design where the funnel and the crane have been positioned abreast, as in the many from higher up shots included here
https://www.bas.ac.uk/polar-operations/ ... hackleton/
- mother-shipping 20 MCM drones? Not a problem
- if the midship open deck is not enough, make the helopad (aft) strong enough for double duty
- and by virtue of having that (large) helopad, can be VERTREP'ed for sustained ops (and is big enough to self deploy)
plus once in the area for Ops, drones can be flown off that deck, in support of the "surface drones"

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby donald_of_tokyo » 18 May 2018, 15:07

Poiuytrewq wrote:Something like,
8x. 105m MHC variants
4x. 105m Global Patrol variants
5x. 120m T31 variants

A combined 3 variant approach built using modern modular methods of construction could really begin to reverse the decline and may help to Initiate an increase in hull numbers once again. As I have commented previously, if RN wanted to do something radical this would be a very good place to start.
With this high spec, I have no hope getting 8+4 MHC vessels. May be 6 in total, or 8 at most.

Do not forget the MCM kit itself for mine-hunting will be very expensive, so available money for hull will be quite limited.

Side-scan sonar operations (REMUS UUVs) and sweep (has a long history of drone operations) can be cheap. These two are important part of MCM operations, but they are the easiest part. On the hunting part, which is the most difficult, I see zero hope it being cheap.

For me, MHC will be a 20 knots or even 18 knots ship, enjoying fat and bulkey hull. If T31e speed requirement can be lowered to 22 knots or so (note that Floreal class is 20 knots), I can see a merit to merge those two. If we are to require 25+ knots to MHC, I am totally against it. A self deploying 25 knot vessel will need neary twice the power requirement than a 20 knots vessel.

Also if the MHC hull are required to be more shock tolerant than T31e, merging the two requirement will result in much more costy hull. All nightmare.

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Re: Mine countermeasures and Hydrographic capability (MHC) (MHPC)

Postby Poiuytrewq » 18 May 2018, 16:41

donald_of_tokyo wrote:With this high spec, I have no hope getting 8+4 MHC vessels. May be 6 in total, or 8 at most.
If the MHC vessels are twice as efficient as the mcmv's that they are replacing how many do RN really need?

Is the cost of the hulls the most important factor? Again taking Kipion as an example, if 2 MHC vessels are replacing 5 vessels (including a Bay) with less than half the crew allocation, the through life costs are going to be drastically reduced. If the through life costs are not going to factored into the equation then it is just another 'cut'

donald_of_tokyo wrote:For me, MHC will be a 20 knots or even 18 knots ship, enjoying fat and bulkey hull. If T31e speed requirement can be lowered to 22 knots or so (note that Floreal class is 20 knots), I can see a merit to merge those two.
I don't think it would be wise to reduce the speed of the T31 down to 20knts. The La Fayette's increased the speed up to 25knts after the Floreal's and probably should be a minimum for the T31.

Given the proposed modular build construction would it not be possible to have a 21 knot propulsion module for the MHC/Patrol variant and a 25knt Frigate module for the the T31? Same hull but different propulsion module's depending on spec of the vessel.

donald_of_tokyo wrote:If we are to require 25+ knots to MHC, I am totally against it. A self deploying 25 knot vessel will need neary twice the power requirement than a 20 knots vessel.
I am not suggesting building a 25knt capable MHC vessel. If the MHC and Patrol variants could share the same basic 105m hull with the same 21knt propulsion system (similar to Holland class) it is worth exploring in my opinion.

donald_of_tokyo wrote:Also if the MHC hull are required to be more shock tolerant than T31e, merging the two requirement will result in much more costy hull. All nightmare.
If the MHC vessels are going to require a highly shock tolerant hull then I agree it changes everything and rules out a lot of options as well as the PSV and other designs. It would also put even more pressure on the budget.

Are you aware if this is a requirement for the MHC vessels?


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