Current & Future Escorts - General Discussion

[dmereifield]

Thanks. Can anyone provide some rough info about this, and also some rough numbers on what the detection range might be for an incoming torpedo (and thus, how long the FF would have to deploy counter measures)? I appreciate that this is highly variable, but some ball park figures would be interesting. Thanks

[seaspear]

speeds ,range and even dwell time of torpedoes are classified but you can believe easily more than 30 n.m but its been almost twenty years since I read specific details but I would not believe they have got less.

[ArmChairCivvy]

thus, how long the FF would have to deploy counter measures

Hmmm, if they do Mach 1 under water
http://www.popsci.com/scitech/article/2 ... ng-torpedo

[abc123]

speeds ,range and even dwell time of torpedoes are classified but you can believe easily more than 30 n.m but its been almost twenty years since I read specific details but I would not believe they have got less.

Yes, exact numbers are definitly classified. But, if we can believe that Italian captain about 20 miles for detection of Type 212 ( and I'm sure that 20 nm isn't the real number, it can be more or less, I presume more ) that gives us some useful informations. Certainly once when she fires a torpedo, that's pretty loud sound, so I believe that a good frigate/sonar catches that a long way...

[donald_of_tokyo]

I think 20nm is a good range for escort.
- To travel 20nm, a 50knot torpedo needs 24 minutes. Of course, SSK can do many tricks so 20nm range is not alway guarantied.
- Super cavitation torpedo Shkval is said to reach 250knots, but it needs 4.8 minutes to travel 20nm. It also lacks sensor, so SSK needs to identify the enemy escort with 6 arcminutes (200m, from side) or 0.6 arcminutes (20m from head) accuracy from 20nm distance for inertial guidance. And anyway the ship can maneuver to avoid hit.

On the other hand, for the long-range torpedo, the CAPTAS equipped escort can be attacked from the longest range. Escort is pinging, so there existence and location (to a few degree accuracy) is WELL KNOWN to the enemy SSK. But escort has ship-topedo-defence system = soft-kill scheme to avoid torpedo attack.

Not sure escort and SSK, which can survive.

[Aethulwulf]

It is interesting to note what Thales say about their own sonars.

•For their UMS 4110 hull mounted sonar they state a typical detection range of 35 km.

•For their CAPTAS-4 variable depth sonar, they quote a detection range of up to 150 km.

Both of these are fitted to the Italian FREMM frigate. The quote about detecting a German SSK at a range of 20 nm could well be talking about detecting using the HMS rather than the VDS...

...it may depend on exactly what was meant by the general term 'detect', or the specific terms detect, characterise, localise, track or target.

[donald_of_tokyo]

Not necessarily.

If the SSN or SSK is in transit, it makes noise and can be relatively easily detected with passive TASS of CAPTAS. I guess this is the 150 km figure.

Every submariners says escort as a easy game. Some exaggeration will be there, but anyhow, if SSKs in AIP mode can be detected in 150km range with CAPTAS-4, and 20 nm range with HMS, it is a very very easy target for escort. In other words, very very hard days for SSK to survive. If yes, a fairly simple ASW escorts can overtake the whole SSK fleet in the globe. But it is said to be not.

Active ASW range is very short, naturally. This is because the power of 1/4 plays. Only a power of 1/2 reaches the target, and only the reflected power of 1/2 reaches back to the escort. So, even if you have 4 times powerful active pinger (CAPTAS4 vs CAPTAS1), if the passive TASS is the same, the range is only (4)^(0.25) = 1.4 times longer. (Actually, the TASS part is not the same, so it is much better for CAPTAS-4.)

But anyway, I cannot believe AIP S212 can be detected from 150 km.

[abc123]

But anyway, I cannot believe AIP S212 can be detected from 150 km.

Me neither. Maybe if under way 20 kts, near the surface etc.

But not in the silent mode, crawling at 4 kts, below thermocline etc.

[LordJim]

But unless a silent means of launching a torpedo exists, surely this would be picked up on passive sonar, alerting the escort and give rough range and bearing on the sub.

[Gabriele]

I've been aboard the Margottini last year and talked to the officer in charge for the ASW area. She said the german submarine was almost 40 kilometers away, and i asked her if it was the kind of contact that could be prosecuted with a MILAS (the italian, non-Vertically Launched ASROC). She said the MILAS was at serious risk of being withdrawn to save money, but i do not know if that eventually happened or if it was avoided.

[Opinion3]

ZeroGravitas's post is spot on!

If I was going to be pedantic the logic needs to be extended further initially it would appear that

Development Cost of T26 + Build Cost of 13 units

needs to be GREATER THAN

Development Cost of T26 + Build Cost of 8 units + Development Cost of T31 + Build cost of x units

For the build of T31 to be worthwhile. However as the Development Cost of T26 is a sunk cost the true consideration is

Does it cost more to design and build a T31 than to build a T26? (and there are plenty off gains to be had due to economies of scale, tooling and site being prepared in favour of the T26).

If this equation does swing in the T31's favour the capabilities and ongoing maintenance / operational costs certainly wont.

I am also struggling with the concept that Bae is ripping us off. The evidence is that a T45 cost a similar amount, the AB ditto, and that both the RCN and RAN both a providing bigger and more in line budgets for the capability needed. We were promised more capable and a bought forward production of the GCS in lieu of a reduced order of T45s. Frequently the T45, Astute and CVF are used to illustrate just how poor procurement, and contract timing has resulted in Massive budgeted overuns THAT ARE LARGELY THE RESULT OF THE GOVERNMENT and not Bae.

[donald_of_tokyo]

French paid 3.3B GBP for 5 FTI. This amounts to 5 unit cost of FREMM. I'm sure French navy is NOT happy with it, but there are at least 2 merits I can see here:

1: operation cost will decrease, while number of ships deployed will be maintained. CODAD is cheaper than CODLAG. Majority of the tasks do not need SCALP, nor super-queit hull, nor range longer than 5000nm. There will be 9 FREMM + 2 FREDA for tasks needing them, so 5 FTI has no problem.

2: ship-building industry gets boosted. There are only small chance to sell FREMM (and even yes, Canada will build on their own), while (maybe) Gowind is still too small in some cases, such as RNZN. Industry design team gets more well trained, and industry gets mature design to sell world wide. (I remember, NAB-san said, for well-balanced designing and build cost learning-curve balance, 6 unit per class is his favorite. )

I'm not sure how these aspects will apply to T31.

1: Even if lean manned, operation cost of "6900t T26 with much less equipment (say, gun, 24CAMM, HMS and a Wildcat)" will never be as low as those for a 4000t light frigate equipped as the same.

2: If it is not BAE, we are going to build-up another design team in BMT/Babcock? If many engineers "swing" from BAE to BMT/Babcock/(stella), then I think it will be worth doing. (Stella is a tiny design office, good for concept design, but never a detailed design of a frigate, I guess).

If it is BAE, modifying Khareef or River B2 can train them? I think, partly yes, since both ship are not well designed in detail as a frigate. Or, why not BAE "buy" Stella, to design BAE-Spartan?

[GibMariner]

here will be 9 FREMM + 2 FREDA for tasks needing them, so 5 FTI has no problem

The order for the last 3 FREMM were cancelled and the 5 FTI ordered in their place. It's 6 FREMM ASW and 2 FREDA plus 5 FTI. They're authorised to operate 15 frontline frigates. They're not doing much better than us. The money they've wasted on this could probably have bought the 17 FREMM originally planned.

[ArmChairCivvy]

The order for the last 3 FREMM were cancelled and the 5 FTI ordered in their place

Check sum: 3 x FR EQT 5 x FT... does that hold ( wrt all the spreadsheet like posts on the topic)?

[ArmChairCivvy]

why not BAE "buy" Stella, to design BAE-Spartan?

Because the Design&Build contract type has proven less than optimal?

[shark bait]

It is interesting to note what Thales say about their own sonars.

•For their UMS 4110 hull mounted sonar they state a typical detection range of 35 km.

•For their CAPTAS-4 variable depth sonar, they quote a detection range of up to 150 km.

Both of these are fitted to the Italian FREMM frigate. The quote about detecting a German SSK at a range of 20 nm could well be talking about detecting using the HMS rather than the VDS...

It's entirely dependent on environmental conditions. Sound propagation is highly variable based on the environment, therefor submarine detection ranges are also highly variable. That’s what makes ASW something of an ‘art’, and why surveys are so incredibly important.

If it’s in the deep open ocean convergence zones will form as bands 30 miles apart where subs can be detected. In the right conditions 3 convergence zones are reliable, which is probably where Thales get their 150km figure from (90miles = 150km). 4th and 5th zones are rare but possible, so I suspect in the right conditions a CAPTAS 4 can work out to 200km.

In other conditions sound can behave like light in a fibre optic, in such conditions it can travel vast distances. The advantage of a variable depth sonar is it can be steered into the ‘fibre optic’ and detect sound over 100 miles. However it again depends on the environment.

[abc123]

It is interesting to note what Thales say about their own sonars.

•For their UMS 4110 hull mounted sonar they state a typical detection range of 35 km.

•For their CAPTAS-4 variable depth sonar, they quote a detection range of up to 150 km.

Both of these are fitted to the Italian FREMM frigate. The quote about detecting a German SSK at a range of 20 nm could well be talking about detecting using the HMS rather than the VDS...

It's entirely dependent on environmental conditions. Sound propagation is highly variable based on the environment, therefor submarine detection ranges are also highly variable. That’s what makes ASW something of an ‘art’, and why surveys are so incredibly important.

If it’s in the deep open ocean convergence zones will form as bands 30 miles apart where subs can be detected. In the right conditions 3 convergence zones are reliable, which is probably where Thales get their 150km figure from (90miles = 150km). 4th and 5th zones are rare but possible, so I suspect in the right conditions a CAPTAS 4 can work out to 200km.

In other conditions sound can behave like light in a fibre optic, in such conditions it can travel vast distances. The advantage of a variable depth sonar is it can be steered into the ‘fibre optic’ and detect sound over 100 miles. However it again depends on the environment.

Agreed.
Also, I really don't think that anybody will tell you their exact ranges and conditions.

[donald_of_tokyo]

The order for the last 3 FREMM were cancelled and the 5 FTI ordered in their place. It's 6 FREMM ASW and 2 FREDA plus 5 FTI. They're authorised to operate 15 frontline frigates. They're not doing much better than us. The money they've wasted on this could probably have bought the 17 FREMM originally planned.

Thanks for correction!

[Ron5]

ZeroGravitas's post is spot on!

If I was going to be pedantic the logic needs to be extended further initially it would appear that

Development Cost of T26 + Build Cost of 13 units

needs to be GREATER THAN

Development Cost of T26 + Build Cost of 8 units + Development Cost of T31 + Build cost of x units

For the build of T31 to be worthwhile. However as the Development Cost of T26 is a sunk cost the true consideration is

Does it cost more to design and build a T31 than to build a T26? (and there are plenty off gains to be had due to economies of scale, tooling and site being prepared in favour of the T26).

If this equation does swing in the T31's favour the capabilities and ongoing maintenance / operational costs certainly wont.

I am also struggling with the concept that Bae is ripping us off. The evidence is that a T45 cost a similar amount, the AB ditto, and that both the RCN and RAN both a providing bigger and more in line budgets for the capability needed. We were promised more capable and a bought forward production of the GCS in lieu of a reduced order of T45s. Frequently the T45, Astute and CVF are used to illustrate just how poor procurement, and contract timing has resulted in Massive budgeted overuns THAT ARE LARGELY THE RESULT OF THE GOVERNMENT and not Bae.

Try your calculations but use annual spend and not program cost. That's what the treasury cares about.

I think you will conclude that a) no concurrent T26/T31 build just like Fallon has stated and b) Parker's NSS is an exercise to the lower annual cost of maintaining a complex warship building capability. He suggests that the only thing to maintain is the ability to assemble blocks that are manufactured by non-warship makers in factory like conditions. He's nuts and/or dishonest, but he'll get his lordship out of it and the Treasury will have the perfect cover to destroy yet another UK asset. 30 years from now, the UK will be buying warships from other countries.

[donald_of_tokyo]

Netherland and Belgium getting in total 4 (2+2) frigates optimized for ASW, and start entering service from the mid-2020s.
http://navaltoday.com/2016/11/14/belgiu ... placement/

Currently in "light frigate" realm, I think there are:
1: "heavy" light frigate
- FTI, taking off land attack and quiet hull from FREMM, keep AAW, gun, and CAPTAS4CI sonar. 4200t FLD. 3.3B GBP for 5 hulls = 660M ave, (470M unit)
2: ASW (medium) light frigates
- Gowind light frigate (SGPV of Malaysian navy). Armed as Khareef (76mm, 12 SAM, 4 SSM, helo), added with CAPTAS-2 and so so good range. 3100t FLD. 2.2B GBP for 6 hulls. = 366M ave.
3: light light frigates or heavy corvettes
- Damen SIGMA frigate 10514. Indonesian ones are armed as Khareef, added with hull sonar and so so good range. 2400t dwl (=FLD?). in case of Rumania, 1.4B GBP for 4 hulls. = 350M ave.
- Khareef itself. No sonar, short range, but with 76mm, 12 SAM, 4 SSM, helo. 2700t FLD, 0.4B GBP for 3 hulls (very cheap...!!)
- many Gowinds and Sigma Corvettes around here.

If, only if, T31 are to be 2B GBP for 6 hull, it is within "2: ASW (medium) light frigates" and "3: light light frigates or heavy corvettes".

[donald_of_tokyo]

I think you will conclude that a) no concurrent T26/T31 build just like Fallon has stated

Although with constant yearly budget, training curve will give 30% of the workloads "free" after hull 3. I know training curve exists, but the "1 every 2 year" pace, politically defined, will make 30% of the labour free, after hull 3. How about slotting T31 here?

30 years from now, the UK will be buying warships from other countries.

Could be. With fixed annual cost, only if T26 was designed with specification similar to FREMM, if should have been very easy.

[Digger22]

I think we need to look back at some previous RN types to remind ourselves of what can be achieved for a given displacement. The old County Class had the following from 6200tons
2X Seacat launchers and associated systems
1 Sea Slug launcher, plus assembly system, plus 24 missile mag plus associated systems (rooms full of Avionics)
4 Exocet launchers plus their associated systems
2 4.5'' In twin Turret
Torpedo tubes, plus associated eq and magazine
Plus aviation facility, and don't forget she had boilers and Steam turbines, with all that associated stuff, and we haven't even touched radar etc...
I don't see how 'Spartan' needs to be 4500-5000tons to be able to carry, a couple of small VLS, one Gun, one CIWS, SSM and aviation?
Things are getting smaller and lighter, and although the Concept brochure for 'Spartan' did talk about being future proof due to inbuilt space, i think 3000-3500tons displacement should do to achieve this. I think we can achieve a decent performance for less tons, otherwise we are going backwards, and cost goes up.

[Repulse]

Can anyone see behind the pay wall?

http://www.janes.com/article/72071/type ... ip-numbers

[donald_of_tokyo]

I don't see how 'Spartan' needs to be 4500-5000tons to be able to carry, a couple of small VLS, one Gun, one CIWS, SSM and aviation?
Things are getting smaller and lighter, and although the Concept brochure for 'Spartan' did talk about being future proof due to inbuilt space, i think 3000-3500tons displacement should do to achieve this. I think we can achieve a decent performance for less tons, otherwise we are going backwards, and cost goes up.

Comparison with old ships needs care. Requirements changes with time.

I agree, "a couple of small VLS, one Gun, one CIWS, SSM and aviation" was packed in 3500t hull in ~2000, as you see in ANZAC class (late 1990s built), exactly the same as you said. And, ANZAC frigate do suffer too small future growth margin. Her accommodation is not comparable to those of T26. (Automation do help, but looking around it looks inflated anyway).

ANZAC's VLS is only 8-cell short-version. 24-cell ExLS shall be a little smaller, but surely not small enough to accommodate 16-cell strike length Mk.41 VLS. ANZAC frigates space is so tight, so both RAN and RNZN banned the TASS room, so I cannot find any place to locate large mission bay.

Only from this, 3500t Spartan (= adding 16-cell strike-length Mk.41 and huge mission bay, with 2020 standard accommodation, over ANZAC class), is simply impossible, even in 1990s, not to mention 2020, I think. I cannot foresee T31 to be packed as densely as ANZAC frigates, and even in ANZAC era, the armaments listed in Spartan brochure cannot be packed in 3500t hull.

Here I take ANZAC for comparison as they are one of the smallest "blue water" light frigates.

On top of this, T21's strongest lessons learned is "good amount of, if not many, future growth margin".

[ArmChairCivvy]

Here I take ANZAC for comparison as they are one of the smallest "blue water" light frigates.

Donald, your approach is a valid one. How sensitive is the outcome to the benchmark, would it look any different, say, with South Africa's MEKOs?