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Re: Current & Future Escorts - General Discussion

Posted: 03 Nov 2018, 21:54
by Repulse
donald_of_tokyo wrote:With that cost we can easily buy 12 T26.
Exactly right @Donald-san, each class built has an inherent cost, both the build and support. If the government was honest they’d being going for 10 T26s, rather than pretending that escort numbers can remain the same (or even grow) without more cash.

I agree with others though that if HMG has built 3 Avenger style ships rather than the B2 Rivers it would have been easier for the government to claim static escort numbers, but they didn’t - however with a little focus they still could.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 00:16
by donald_of_tokyo
Poiuytrewq wrote:It would be more like £860m a hull or £1.72bn if you drop back to six T26's.
I think you ignore design+initial cost. If you see FREMM wiki, you can find it. It is based on some French senate answer.

(But I cannot read .... )
http://www.senat.fr/rap/a14-110-8/a14-1 ... tml#toc308

Ignoring design+initial, a 2nd-tier frigate option becomes attractive. But, design+initial cost is huge...
Ron5 wrote:1. Not sure what size has to do with Leanders electric propulsion. Far larger ships are diesel electric.
Sorry you are right. The Leaner small size merit is on "can do with 2 diesel". And, it is "in-directly" cause the need for electric drive (for low speed operation) and so on so on..... But, yes no directly related ...
2. Electric propulsion does not confer silence in itself. Diesel generators are still running and in Leander, the electric motors drive the shafts through large gearboxes. Both, if not silenced, will produce plenty of noise.
You are right. At the same time, there are many "silent rafted diesel gensets". With no mechanical shaft connected, quietization becomes very very easy (of course not for free). Gearbox is also important, but for example, FREMM is using quietezed gear box. Interesting that it is considered cheaper than "co-axial" motor option.
3. We had the discussion many times before. I don't believe the size or type of sonar can overcome a noisy ship. It's about signal to noise ratio.
4. Did the French really make that trade off or are we just speculating?
It is claimed by DCNS guy when FTI and CAPTAS4CI was introduced.

Yes, it is signal to noise ratio. In case of passive ASW, yes, hull quietness is the only option. In active ASW tactics, if you increase signal, you can overcome noise (to some extent).
- Increasing signal = 4-barrel VDS (CAPTAS-4 and 4CI) is twice better than CAPTAS-2.
- Increasing signal = Because active ASW's "detection range" is proportional to "(power/noise)**(1/4)", if purely about the range, more hull might be better, depending on the tactics and (power/noise) ratio.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 02:34
by Lord Jim
So are we now proposing an Active/Passive partnership between the T-31e and the T-26 respectively? Having the T-31e as sort of beater pinging away with active sonar whilst the very quiet T-26 coasts along listening with their passive arrays acting as the shooter together with Helos? Would such a partnership work? The idea sound interesting.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 03:11
by ArmChairCivvy
donald_of_tokyo wrote:more hull might be better, depending on the tactics
+
Lord Jim wrote:proposing an Active/Passive partnership
Other people have come to the same conclusion https://www.liquid-robotics.com/press-r ... ory-board/
but ' thinking outside the box' can make the additional 'hulls' much cheaper, both to buy and to operate.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 06:28
by Lord Jim
Once again I make a case for the main gun on the T-31e.

or alternatively


Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 09:07
by Repulse
Lord Jim wrote:So are we now proposing an Active/Passive partnership between the T-31e and the T-26 respectively? Having the T-31e as sort of beater pinging away with active sonar whilst the very quiet T-26 coasts along listening with their passive arrays acting as the shooter together with Helos? Would such a partnership work? The idea sound interesting.
It is interesting, but for god sake let’s not waste £250mn on building a valuable sitting target with close to 100 people on board. A USV, like the USN Sea Hunter concept maybe, but if it needs to be manned either go for something smaller like the French Antares class or a modified River Class with some additional self defence. Either way should be less than £100mn per hull.

Buy 5 and add a T26 or two :thumbup:

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 10:14
by NickC
Repulse wrote:Re: Current & Future Escorts - General Discussion
Unread postby Repulse » 04 Nov 2018, 09:07

Lord Jim wrote:
So are we now proposing an Active/Passive partnership between the T-31e and the T-26 respectively? Having the T-31e as sort of beater pinging away with active sonar whilst the very quiet T-26 coasts along listening with their passive arrays acting as the shooter together with Helos? Would such a partnership work? The idea sound interesting.


It is interesting, but for god sake let’s not waste £250mn on building a valuable sitting target with close to 100 people on board. A USV, like the USN Sea Hunter concept maybe, but if it needs to be manned either go for something smaller like the French Antares class or a modified River Class with some additional self defence. Either way should be less than £100mn per hull.

Buy 5 and add a T26 or two
My understanding is that with the new generation of extremely quiet submarines you need a very powerful active sonar, TAS no longer effective, so left with a very expensive and limited number of T26s at ~£1B as sitting targets when using active VDS with close to 150 people on board.

So do agree with Lord Jim, my view expressed many months ago was to move to an dedicated ASW squadrons, say with one T23s with its passive TAS and Merlin and may be two T31s with VDS and even no helicopter for ~ £120M per ship. The USN Sea Hunter or any other UV are small and so would not have the necessary power for an effective active sonar. You could fit the T31 with an anti-torpedo system :)

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 10:45
by Repulse
NickC wrote:My understanding is that with the new generation of extremely quiet submarines you need a very powerful active sonar, TAS no longer effective, so left with a very expensive and limited number of T26s at ~£1B as sitting targets when using active VDS with close to 150 people on board.
I’ve no doubt that new submarines are getting quieter - but there are two sides to every coin and detection will keep pace. The T26 has an ultra quiet hull / engines - the T31e will not. The T26 will have standoff ASW weapons and ability to deploy / operate complex off board ASW sensors including 1-2 Merlins - the amount of money available will mean the T31e will not. Operating a TAS is part of the solution but not all of it.

I’d rather be sat deploying off board pingers at range on an ultra quiet ship able to kill at range, rather than sat on a noisy ship with a local pinger with limited kill capability.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 10:46
by SW1
If asw was the driver for type 31 why wait another 6 years. Fit the remaining type 23s with tails and train up additional operators. My guess however is it’s not.

All navy warships are general purpose at the end of the day. I’m told in general passive asw is for hunting ssns and active for ssk’s in more noisey littoral areas. Are we really going to send a type 31 looking for an ssk?

Firescout with ultra sonobuoy pods or usv with active pingers are all currently available to form part of an active sub hunt. These can be deployed from anything from a type 26 to an lpd. Couple that to similar sonobouy pods on protector and the multi static processors to exploit it. It doesn’t need a type 31.


I haven’t seen a gd answer to what do we want type 31 to do and where. No one has explained why type 31 is the answer other than it’s cheap and want our shipyards to build more ships. I would suggest we just build as many type 26 ias the budget allows in block form if necessary and scale our ambitions accordingly.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 13:58
by donald_of_tokyo
From T31 thread....
RetroSicotte wrote:
donald_of_tokyo wrote:For me, the degradation in T23GP to Leander is negligible to those capability increase.
As has been said many times, I'm afraid, this logic is not sound. 8x ASW frigates being replaced by 8x ASW frigates is a equal replacement, not an increase.

The only way it is an "increase" is if the entire world didn't also improve their capabilities on a ship by ship basis. But they did. Thus, the angle that "The RN can absorb losing five fighting frigates because T26 is better" is simply not true.

Having 8 T26 in the 2030's is no more effective than having 8 T23s in the 90s were in context to their environment...and thats before we remember that the 8 T26 are not just replacing 8 T23. They're replacing 8 T23 and 4 T22. So it is a drop in 4 ASW frigates that has never been addressed.

It is falling into the trap of what the Gov/MoD wants you to think to keep ignoring the T22's presence in this. It is not 8 for 8.
Thanks, I totally agree to your point. And still I will continue my discussion.

You are proposing for increase of money. No problem. I am basing my comments on the current plan.

Compared to ideal world in which all 13 (or even 16) T23 have CAPTAS4, T31 is a big capability reduction. But, T23GP was not used as ASW frigate for a decade. Now we even see 30% less sea-going days of all 13 T23s compared to those pre-2015. In other words, even a few T23 are not used. This is the current reality.

So "the degradation in T23GP to Leander is negligible to those capability increase", this argument does not change, for me.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 14:21
by Repulse
Even putting Russia to one side, the worlds oceans will become more contested by local players (like Iran) and global players like China (or through proxies such as Pakistan). Put in this perspective the idea of a low end global frigate sailing the seas waving the RN Ensign becomes even more ludicrous.

I’m all for a volume of multi-role Patrol (MHPC) Sloops able to protect UK/BOT EEZs and have secondary war roles, but the RN needs serious ships for serious times - increasingly the fleet of 1st tier ASW Escorts to 10+ should not be a stretch for a budget as big as ours- it’s just down to priorities and focus.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 15:27
by Lord Jim
I do not think it is the World's Oceans that are going to be an issue like they were during the Cold War. The issue in my mind is going to be very quiet conventional submarines in coastal/littoral areas where the TASS is far less effective. Few nations have a true oceanic submarine capability, either lacking effective platforms or the training to use them properly. If we look at a conflict around Norway NATO will need ASW assets that can sanitise the coastal region. Yes there will still need to be a ASW presence protect traffic in the Atlantic and the convoys that will be crossing over to Europe, but the latter is going to be the main domain of the USN. The UK will probably be the leader in any operation to move and land troop to reinforce Norway and will need to commit all available assets to this. Therefore the RN needs a good "Active" asset to work inshore of the Carrier Group. Whether this is a T-31e with a whacking great hull mounted active sonar or a T-31 active as a mothership to two or more remote platforms equipped with active sonar is up for debate. Such platforms will also need an old school ASW mortar/rocket system rather than more complex systems like ASROC or even ASW torpedoes, a sort of grand child of limbo like the latest Swedish offering. These are relatively inexpensive but very effective in coastal/littoral regions. Would it be possible to develop an ASW style SDB or micro torpedo, able to be salvo launched and then use an active seeker to home in on a near by enemy Sub. This would be an evolution of the ASW mortar/rocket system adding some smarts. They could even be pre-programmed prior to launch with the acoustic signature of the vessel being hunted. Now there's a thought!

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 15:34
by Ron5
donald_of_tokyo wrote: Poiuytrewq wrote:
It would be more like £860m a hull or £1.72bn if you drop back to six T26's.

I think you ignore design+initial cost. If you see FREMM wiki, you can find it. It is based on some French senate answer.

(But I cannot read .... )
http://www.senat.fr/rap/a14-110-8/a14-1 ... tml#toc308
Here's the translation:

"3. The multi-mission frigate (FREMM)

Subject to sub-Action 73 program 146, the FREMM frigates are of the class of 6000 tons who board the NH90 helicopter (see above ) and implement anti-ship capabilities (sea-sea missiles) , self-defense means against submarines (MU 90 torpedoes) and for the anti Version underwater (ASM), anti-aircraft self-defense capacity (Aster 15) and for the version enhanced capacity air defense missile ASTER 15 and 30. the program also covers boarding a typing capacity in the depth (naval cruise missiles) and a sonar capacity for submarine detection.

The FREMM thus constitute the main structure of the naval force in the different fields of struggle to the sea; they are also able to operate as part of joint or combined cooperation, alone or in a naval force. These buildings are intended to replace most of the old frigates , including the types F67 Tourville - already disarmed - F70 Georges Leygues and FAA Cassard .

The frigate Aquitaine , FREMM first of the series, was commissioned in November 2012. The production of the series continues with the launching of the frigate No. 4 Languedoc in July, receiving the frigate No. 2 Normandy and the first outlet to the sea of the frigate 3 Provence end of 2014. As part of the CA 2014 to 2019, the implementation contract was revised to adapt the pace of delivery: about 11 FREMM already ordered , 6 frigates ( Version ASM ) will be delivered by 2019 . The next two FREMM will have a capacity of anti-aircraft defense extended to replace the two old frigates generationCassard and Jean Bart , and complete the two Horizon type units. For the following three, which will be delivered after 2019, the type can be adapted, depending on the needs analysis and market, the decision is to be taken in 2016.

This program is conducted within the Organization for Joint Armament Cooperation (OCCAR), in bipartisan cooperation with Italy. The arrangement framework of this cooperation, signed in 2005, covers the definition, design, development, construction and support of frigates. The cost of the program amounted to just over 9.5 billion euros to the economic conditions of 2014, and the unit cost of a FREMM, excluding non-recurring development costs and initial logistics, to 670 million .

The main commitments for next year (507 million euros and 362.7 million in AE CP) cover economic increases"

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 15:39
by Ron5
donald_of_tokyo wrote:Gearbox is also important, but for example, FREMM is using quietezed gear box. Interesting that it is considered cheaper than "co-axial" motor option.
A higher spinning, lower torque, electric motor running through a gear box to the shaft is both smaller and cheaper. Some of those shaft mounted electric motors (like on the t45) get rather large.

I believe the choices of a hybrid propulsion system for both Al Khareef and Leander were driven by a desire for fuel economy and not so much for quietness.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 15:40
by Tempest414
Repulse wrote:increasingly the fleet of 1st tier ASW Escorts to 10+ should not be a stretch for a budget as big as ours- it’s just down to priorities and focus.
I agree and it can be done by committing to 1.1 billion pound per year for 25 year this could allow for 12 frigates + 12 Multi- mission MHPC + 3 FSS + 3 B2 Bay + 1 LPH within the first 15 years which in my mind is within current spending

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 15:42
by Ron5
donald_of_tokyo wrote: 3. We had the discussion many times before. I don't believe the size or type of sonar can overcome a noisy ship. It's about signal to noise ratio.
4. Did the French really make that trade off or are we just speculating?

It is claimed by DCNS guy when FTI and CAPTAS4CI was introduced.

Yes, it is signal to noise ratio. In case of passive ASW, yes, hull quietness is the only option. In active ASW tactics, if you increase signal, you can overcome noise (to some extent).
- Increasing signal = 4-barrel VDS (CAPTAS-4 and 4CI) is twice better than CAPTAS-2.
- Increasing signal = Because active ASW's "detection range" is proportional to "(power/noise)**(1/4)", if purely about the range, more hull might be better, depending on the tactics and (power/noise) ratio.
Thank you. Interesting.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 15:57
by donald_of_tokyo
Ron5 wrote:A higher spinning, lower torque, electric motor running through a gear box to the shaft is both smaller and cheaper. Some of those shaft mounted electric motors (like on the t45) get rather large.
I believe the choices of a hybrid propulsion system for both Al Khareef and Leander were driven by a desire for fuel economy and not so much for quietness.
Agreed. My point is, it will be much easier to "quietize" than CODAD = a large diesel with big piston, and with a shaft directly connected to the engine and to the hull, even in low speed.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 16:00
by donald_of_tokyo
Repulse wrote:increasingly the fleet of 1st tier ASW Escorts to 10+ should not be a stretch for a budget as big as ours- it’s just down to priorities and focus.
Umm, so you propose what to cut, as low priority and no-focus?
Tempest414 wrote:I agree and it can be done by committing to 1.1 billion pound per year for 25 year this could allow for 12 frigates + 12 Multi- mission MHPC + 3 FSS + 3 B2 Bay + 1 LPH within the first 15 years which in my mind is within current spending
I do not think it is in current spending. There is a reason why we are not planned to get it now. Sorry, I tend to be not-optimistic, because optimism did huge "bad", much more than good, in RN history for two decades.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 16:18
by donald_of_tokyo
Lord Jim wrote:Once again I make a case for the main gun on the T-31e.
Thanks. For 76mm Strales CLOS guided ammunition, I think this movie is better.


To say the truth, I am not much optimistic about its capability. Line of sight means weak against target maneuver. Good for Exocet/Harpoon era ASM, drones and helicopters, and of course fast attack boats. But not sure for NSM, LRASM (high maneuver) or Blamos (Mach 3). I might be wrong. Also LOS means its range will be limited, because the dart is not on ballistic trajectory.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 16:31
by Caribbean
Repulse wrote:I’m all for a volume of multi-role Patrol (MHPC) Sloops able to protect UK/BOT EEZs and have secondary war roles,
I think you just described the baseline T31.
UK/BOT EEZs - Light helicopter, fast boats, HADR supplies
Secondary war role - NGFS, convoy local air defence, contributor to ASW
I'm not sure why so many people here want to put our sailors in such low-end boats like the Venari, designed to have nothing more than junk-busting capabilities. We don't send the Rivers on anti-pirate patrols, but for some reason, an identically-equipped Venari is going to be able to do the job.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 16:35
by Repulse
donald_of_tokyo wrote:Umm, so you propose what to cut, as low priority and no-focus?
Here’s a list of 3 items for starters I’d cut / rationalise to get another couple of 1st rate ASW Frigates.

- A the idea of a globally deployable Army Division
- Foward bases in Germany and the the Baltics
- The T31 programme

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 16:40
by Repulse
Caribbean wrote:I think you just described the baseline T31.
No I haven’t - a B2 River with a hangar is more than enough for what I describe, which is half the price of what is being touted for a T31 (most of which will go on design and build start up costs).

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 17:09
by ArmChairCivvy
Repulse wrote:Foward bases in Germany and the the Baltics
The latest proposal is to keep 60 folks looking after the big A/C garage, and also keep the exercise area available. Or that is what I picked up, MDP might come out with something different.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 17:10
by Caribbean
Repulse wrote:a B2 River with a hangar
... has no feasible "secondary war role", except perhaps as a floating ambulance. An OPV will get nowhere near anything involving shooting.

Re: Current & Future Escorts - General Discussion

Posted: 04 Nov 2018, 17:21
by ArmChairCivvy
Caribbean wrote:has no feasible "secondary war role", except perhaps as a floating ambulance.
Or as a "door guard" against infiltration of supply harbours, back at home.