Royal Navy Type 26 Frigate

MoD has issued a request for expressions of interest for the Type 26 for a Mk 41 strike length cell rocket launched rapid reaction light or very light torpedo carrier with a minimum range exceeding that of the maximum range of heavy torpedoes (similar to the ASROC). It said it will also consider drone based systems.
 
WatcherZero said:
MoD has issued a request for expressions of interest for the Type 26 for a Mk 41 cell rocket launched light or very light torpedo with a minimum range exceeding that of the maximum range of heavy torpedoes.
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That would be >30nm (56km) in the case of the Spearfish.
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Only the MILAS comes close to that.
 
Army rations when I was about were 'formulated' to reduce the need to remove solids. Even the nbc system could not remove the gaseous emissions from the locked down Chieftain.

After 24/48 hours, eye watering.
 
Something else to remember, this is through a charcoal lined NBC suit........
 
WatcherZero said:
MoD has issued a request for expressions of interest for the Type 26 for a Mk 41 strike length cell rocket launched rapid reaction light or very light torpedo carrier with a minimum range exceeding that of the maximum range of heavy torpedoes (similar to the ASROC). It said it will also consider drone based systems.
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Drone suggests the "rapid" requirement isn't all that rapid. Tomahawk ASW? ;) (Or an actual ASW version of FC/ASW).
 
Kiltonge said:
As a non-matelot, I am perplexed as to how it's 'cheaper' to build two entirely different but nearly dimensionally identical hulls, rather than just build a common hull and make two classes by equipping them to different standards.
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ISTR someone claiming the deciding factor was "We're not giving the Type 31 to BAE", and that that was decided in advance. As Type 26 is a BAE design....

Of course Type 31 actually is a common hull fitted out differently. It's just the hull it's common with is the Danish Iver Huitfeld/Absalon classes.
 
TomS said:
Drone suggests the "rapid" requirement isn't all that rapid. Tomahawk ASW? ;) (Or an actual ASW version of FC/ASW).
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I think they are leaving the door open so proposals can be legally considered, something like a tube drone, or a tailored version of the Banshee 80+ or NG drone carried torpedo would be pretty rapid (unladen launch speed 180 km/h max speed 900 km/h with 60 minute endurance and they have carried air-to-air missiles before) while something like a T-650 drone wouldn't be as rapid but could potentially have great range and linger capability so could be complementary if the rocket systems range was on the shorter side.
 
Kiltonge said:
As a non-matelot, I am perplexed as to how it's 'cheaper' to build two entirely different but nearly dimensionally identical hulls, rather than just build a common hull and make two classes by equipping them to different standards.
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If you want to optimize your ship to be superior in a given function, that needs to be reflected in the hull design.

The Type 31 is a GPF derived from a Frigate/Support Ship hybrid, so less optimized for ASW. However, it has to be noted that the RDN has re-classified the T31 predecessor as an ASW frigate, and plans to add towed sonar to them. How successful this conversion is something for the future, though I doubt it would be as good as a specialized ship.
 
starviking said:
If you want to optimize your ship to be superior in a given function, that needs to be reflected in the hull design.

The Type 31 is a GPF derived from a Frigate/Support Ship hybrid, so less optimized for ASW. However, it has to be noted that the RDN has re-classified the T31 predecessor as an ASW frigate, and plans to add towed sonar to them. How successful this conversion is something for the future, though I doubt it would be as good as a specialized ship.
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Not just hull shape, there would be major differences in internal arrangements, starting with whether the propulsion machinery is rafted. Two ships with the same hull could be quite different in that respect, but every change is an expense, so it might not be cheap enough to "de-scope" a high-end ship like the T26 compared to building a less sophisticated design like the T31 from scratch.
 
TomS said:
Drone suggests the "rapid" requirement isn't all that rapid. Tomahawk ASW? ;) (Or an actual ASW version of FC/ASW).
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What I'm hoping for, I suspect in vain, is for someone to propose a GLSDB style weapon....rocket booster with Stingray mounted on top with a gliding wing kit similar to HAAWC. We need a high altitude Stingray deployment solution for P-8 so it would be good to combine the 2 aims. It would also open the door for a UK capability for other uses like a GLSDB delivering Spear variants (including hopefully MRUSW).

The desire to outrange HWT appears to mean that VL-ASROC is out of the frame immediately...K-ASROC as well. Type 07 could perhaps meet the requirement, but only if you really limit what you mean by HWT range....MILAS isn't VL capable (and apparently has been removed from ships). Basically the 'West' could really do with a longer ranged modern ASROC, a niche that should have been filled by Sea Lance....
 
timmymagic said:
What I'm hoping for, I suspect in vain, is for someone to propose a GLSDB style weapon....rocket booster with Stingray mounted on top with a gliding wing kit similar to HAAWC. We need a high altitude Stingray deployment solution for P-8 so it would be good to combine the 2 aims. It would also open the door for a UK capability for other uses like a GLSDB delivering Spear variants (including hopefully MRUSW).

The desire to outrange HWT appears to mean that VL-ASROC is out of the frame immediately...K-ASROC as well. Type 07 could perhaps meet the requirement, but only if you really limit what you mean by HWT range....MILAS isn't VL capable (and apparently has been removed from ships). Basically the 'West' could really do with a longer ranged modern ASROC, a niche that should have been filled by Sea Lance....
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I'm wondering if VLA-ER (essentially VLA with a wing kit added to the torpedo) is further along than realized. It was supposedly shelved around 2010, but maybe LM has it to a point they could seriously propose it.

Post in thread 'RUR-5 ASROC and RUM-139 VL-ASROC (VLA)' https://www.secretprojects.co.uk/threads/rur-5-asroc-and-rum-139-vl-asroc-vla.43255/post-669560


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WatcherZero said:
MoD has issued a request for expressions of interest for the Type 26 for a Mk 41 strike length cell rocket launched rapid reaction light or very light torpedo carrier with a minimum range exceeding that of the maximum range of heavy torpedoes (similar to the ASROC). It said it will also consider drone based systems.
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_Min_ VL-torp range exceeding max heavyweight torp range seems odd. You definitely want a _max_ range greater than that, but _min_ range would leave a large gap (c7nm out to 30nm) between the maximum range of ship-launched Stingray and the max range of heavyweight torpedoes where a sub could operate without being engaged, while being able to engage the surface ship.
 
DWG said:
_Min_ VL-torp range exceeding max heavyweight torp range seems odd. You definitely want a _max_ range greater than that, but _min_ range would leave a large gap (c7nm out to 30nm) between the maximum range of ship-launched Stingray and the max range of heavyweight torpedoes where a sub could operate without being engaged, while being able to engage the surface ship.
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WatcherZero's 'minimum range exceeding' should probably be interpreted as 'maximum range shall not be less than'. The actual language from the RFI (here) is 'The LRAW concept provides an extended range delivery means for a Lightweight Torpedo (LWT) or Very Light Weight (VLWT) Torpedo effector against submarine contacts, cued by organic or third-party sensor detection. Engagement ranges are to comfortably overmatch those of current and forecast threat Heavy Weight Torpedoes.' Overmatch isn't necessarily the same thing as winning at Top Trumps, of course.

The assumption to be used for costings is a total global buy of 500 weapons, and the MoD is inviting a MOTS or novel solution.
 
timmymagic said:
It would appear to offer range near the right level (but not by much)....I'm guessing the article gets the speed wrong though as it says it travels at 200 knots...
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If we figure 4-5 times the nominal 12nm range of VLA, that's 48-60nm. I'd consider that a "comfortable overmatch" against most heavyweight torps. Even the Type 65 can't be launched from 60nm out.
 
Yellow Palace said:
WatcherZero's 'minimum range exceeding' should probably be interpreted as 'maximum range shall not be less than'. The actual language from the RFI (here) is 'The LRAW concept provides an extended range delivery means for a Lightweight Torpedo (LWT) or Very Light Weight (VLWT) Torpedo effector against submarine contacts, cued by organic or third-party sensor detection. Engagement ranges are to comfortably overmatch those of current and forecast threat Heavy Weight Torpedoes.' Overmatch isn't necessarily the same thing as winning at Top Trumps, of course.

The assumption to be used for costings is a total global buy of 500 weapons, and the MoD is inviting a MOTS or novel solution.
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Remember that HWTs mean getting within visual detection range of the target. Periscope range.

So in all honesty, VL-ASROC does meet the standard, just barely, because you're going to be able to see a frigate at ~8-10nmi. Carrier at more like 15nmi, but the ASW escorts should be a lot closer to the sub.

And it's in the visual approach to the target that makes a submarine most easily detected by air or ship sensors. You're above the shallow thermocline so the hull sonar can see/hear you, if the waves aren't huge the sub can be seen in the water, and you have a radar target sticking out of the water (the periscope).
 
Scott Kenny said:
Remember that HWTs mean getting within visual detection range of the target. Periscope range.

So in all honesty, VL-ASROC does meet the standard, just barely, because you're going to be able to see a frigate at ~8-10nmi. Carrier at more like 15nmi, but the ASW escorts should be a lot closer to the sub.

And it's in the visual approach to the target that makes a submarine most easily detected by air or ship sensors. You're above the shallow thermocline so the hull sonar can see/hear you, if the waves aren't huge the sub can be seen in the water, and you have a radar target sticking out of the water (the periscope).
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Sorry I don't think the RN are daft enough to be speccing an ASW weapon to overmatch HWT at periscope range in 2024...they're looking for a minimum of 40-50nm I suspect.
 
timmymagic said:
Sorry I don't think the RN are daft enough to be speccing an ASW weapon to overmatch HWT at periscope range in 2024...they're looking for a minimum of 40-50nm I suspect.
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If I'm that far away I'm launching Harpoons or Tomahawks, not Mk48s...
 
And the data used to launch that longer-range ASW weapon is almost certainly being fed to the firing ship by other sensor sources - other ships, sonobuoys, aircraft (manned or unmanned, fixed-wing or rotary), sea-bottom sensor net... so the ability of the firing ship to personally see and ID the target is not required at all (ROEs permitting).

And if the sub has in its computers the sound profiles of enemy ships and gets a positive passive sonar match for targets in a location where enemy ships are known to be (or are expected), that would allow launching of torpedoes (or weapons such as SubRoc) from the maximum range of the weapon (and not requiring periscope confirmation) if so desired (ROEs permitting).
 
DWG said:
minimum maximum range
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Which is of course a very different kettle of fish to maximum minimum range.
Scott Kenny said:
If I'm that far away I'm launching Harpoons or Tomahawks, not Mk48s...
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The number to think about is engagement range, not weapon range. For both the torpedo and the LRAW. The long range of torpedoes isn't to sink ships at tens of kilometres range - it's to sink submarines (and, incidentally, ships) that are running away very quickly.

Unless it's a wake-homer, in which case the long range is because it has to follow a very inefficient course.
 
Yellow Palace said:
The number to think about is engagement range, not weapon range. For both the torpedo and the LRAW. The long range of torpedoes isn't to sink ships at tens of kilometres range - it's to sink submarines (and, incidentally, ships) that are running away very quickly.

Unless it's a wake-homer, in which case the long range is because it has to follow a very inefficient course.
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Exactly. Engagement range with a torpedo is within visual range of the surface ship. Just like in WW2. Or in the Falklands.

On the order of 15-20km for most ships, more like 30km for carriers.
 
Scott Kenny said:
Exactly. Engagement range with a torpedo is within visual range of the surface ship. Just like in WW2. Or in the Falklands.

On the order of 15-20km for most ships, more like 30km for carriers.
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A few years ago Jane’s revealed that the German Sea Hake torpedo had the ability to to come near the surface and raise an aerial of some sort to get a GPS fix and proceed onward to the target with passive homing. Putting aside rules of engagement that require visual periscope (optronic mast) confirmation of a target, there’s no reason to expect an attacking submarine to get within visual range before firing. Ever since the days of torpedo tube launched Exocets and Harpoons, this hasn’t been an expectation.

It is fun for submariners to take picture of ships during Perisher or other exercises.
 
If you can do a TMA on a sub and engage without ever seeing it (and let's remember HMS Venturer did that vs U-864 in 1945), then engaging a surface ship on the same basis isn't that much more difficult*, provided your sonar and torpedo are up to it. And if your torpedo is packing a bucket of instant sunshine as a warhead (a Cold War scenario we need to start thinking about again given Vlad's fetish for nuclear threats), then the last thing the sub-commander wants to do is get in close. And if you want to stop him, you need to do it before he gets in range - think of scenarios like a slow moving convoy, or an amphibious group offshore a landing beach, where running away is less of an option.

Which scenario, and this RfP, makes it interesting that HMS Venturer is one of the new Type 31s.

* Geometrically it's simpler, but the sonar conditions are probably a bit more challenging.
 
Forest Green said:
Can't they detect the acoustic signature BVR?
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Yes.

But it's of questionable accuracy in terms of getting a torpedo to within the torpedo's terminal guidance. There's still the question of positively IDing the target. At the very least, you need to make sure it's not one of yours, torpedoes do NOT have IFF systems.

Remember that the torpedo is relatively slow compared to the targets, traveling at maybe double the target's speed or so. This slow speed means that the torpedo doesn't only travel the range at the time of launch, but it travels at some geometric multiple of that range based on the target's speed and crossing angle.

Also, consider what happens when the targets zig sharply away from the submarine. Whether the target heard the torpedo(es) incoming or not doesn't matter, they zigged away. Now the torpedo is in a stern chase and if we're talking carrier groups they're doing 25 knots for flight ops. Jane's gives the Mk48 at 54000yd range at 40kts, 42000yds at 55kts. At most, you might shoot at maybe half that theoretical max range to give some chase ability to your torpedoes, assuming that they're still on the wire to let their course to target be changed.

If your target is a sub, you want to be even closer because they will hear either the launch transient or the torpedo screws as soon as you launch and immediately run away. Rumor has it that the Seawolf class can outrun a Mk48 fired from 5400 yards, between their top speed and how quickly they accelerate. I'd expect the Virginia class to be similar (not as much horsepower, but smaller hull so less drag).
 
Scott Kenny said:
Now the torpedo is in a stern chase and if we're talking carrier groups they're doing 25 knots for flight ops. Jane's gives the Mk48 at 54000yd range at 40kts, 42000yds at 55kts.
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In a straight stern chase, that gives a maximum engagement range - the calculation is straightforward - of 22,900 yards. Just 19,000 yards if the carrier is doing 30 knots. Interestingly enough, that's at the higher speed setting in both cases. You're ideally not going to choose an attack angle that commits you to a stern chase. But you're also not going to fire at maximum range if you have any alternative at all, to give margin for manoeuver.

If I were a submarine captain (and there are many good reasons why I'm not), I'd be wary of firing at a longer range than what a stern chase would allow. I'd want to get as close as I could while still being confident of getting away to give my torpedoes the best chance of defeating evasive manoeuvers.
 
Scott Kenny said:
Yes.

But it's of questionable accuracy in terms of getting a torpedo to within the torpedo's terminal guidance. There's still the question of positively IDing the target. At the very least, you need to make sure it's not one of yours, torpedoes do NOT have IFF systems.
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There's a comprehensive acoustic signature database for that. It's a lot more than just picking up a noise.
 
Yellow Palace said:
In a straight stern chase, that gives a maximum engagement range - the calculation is straightforward - of 22,900 yards. Just 19,000 yards if the carrier is doing 30 knots. Interestingly enough, that's at the higher speed setting in both cases. You're ideally not going to choose an attack angle that commits you to a stern chase. But you're also not going to fire at maximum range if you have any alternative at all, to give margin for manoeuver.

If I were a submarine captain (and there are many good reasons why I'm not), I'd be wary of firing at a longer range than what a stern chase would allow. I'd want to get as close as I could while still being confident of getting away to give my torpedoes the best chance of defeating evasive manoeuvers.
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Exactly.

So even if the torpedo has a 27nmi max range, the submarine needs to be well inside this or the target could escape.

Now that I found a reference online for Guidance Wire length, there's 20,000yds of wire to work with, which provides another partial limit to max range shots. While you can set up the torpedo to do various things when the wire breaks or runs out, those also increase the distance the torpedo travels because it's no longer moving in a straight line.

Wake homing torpedoes don't travel in a straight line either, so their effective range is notably less than their theoretical endurance.

Blargh, my brain isn't mathing right now. What's the max engagement range for a Spearfish chasing a carrier at 25 or 30 knots? Spearfish does 80 knots and has a 60,000yd range.
 
Scott Kenny said:
Exactly.

So even if the torpedo has a 27nmi max range, the submarine needs to be well inside this or the target could escape.

Now that I found a reference online for Guidance Wire length, there's 20,000yds of wire to work with, which provides another partial limit to max range shots. While you can set up the torpedo to do various things when the wire breaks or runs out, those also increase the distance the torpedo travels because it's no longer moving in a straight line.

Wake homing torpedoes don't travel in a straight line either, so their effective range is notably less than their theoretical endurance.

Blargh, my brain isn't mathing right now. What's the max engagement range for a Spearfish chasing a carrier at 25 or 30 knots? Spearfish does 80 knots and has a 60,000yd range.
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For 25kts, it would be 56km (30nm) - [56km/(80/25)] = 56 - 56/3.2 = 56 - 17.5 = 38.5km.
 
Scott Kenny said:
Blargh, my brain isn't mathing right now. What's the max engagement range for a Spearfish chasing a carrier at 25 or 30 knots? Spearfish does 80 knots and has a 60,000yd range.
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I get 41,250 and 37,500 yards respectively. I also don't believe 80 knots for 60,000 yards; it's over twice the speed-range performance of a Mk 48. A more likely figure is 25,000 yards at 80 knots, based on my copy of Friedman's World Naval Weapons Systems, which would give a maximum range vs. a carrier of 17,200 yards (at 25 knots) or 15,600 yards (at 30 knots).

If you believe the Mk 48 needs to be inside 5,400 yards to kill a SEAWOLF - and that implies some rather implausible performance - then a Spearfish can do it at 10,000 yards. Or 24,000 yards if you believe the 80 knots/60,000 miles figure. Spearfish is good, but it's not that good.
 
I believe Spearfish is also much slower at greater depths due to the back-pressure on the turbine. To make use of the high speed they run it out at a shallow depth, and dive down on to the target (if it is a submerged submarine).
 
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Yellow Palace said:
I get 41,250 and 37,500 yards respectively. I also don't believe 80 knots for 60,000 yards; it's over twice the speed-range performance of a Mk 48. A more likely figure is 25,000 yards at 80 knots, based on my copy of Friedman's World Naval Weapons Systems, which would give a maximum range vs. a carrier of 17,200 yards (at 25 knots) or 15,600 yards (at 30 knots).

If you believe the Mk 48 needs to be inside 5,400 yards to kill a SEAWOLF - and that implies some rather implausible performance - then a Spearfish can do it at 10,000 yards. Or 24,000 yards if you believe the 80 knots/60,000 miles figure. Spearfish is good, but it's not that good.
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It's 26km (14nm) at 80 knots and 56km (30nm) at 55 knots reading around the links on wiki. So back to 56km against a 25 knot target:

56 - 56/(55/25) = 30.5km
 
A Tentative Fleet Plan said:
I believe Spearfish is also much slower at greater depths due to the back-pressure on the turbine. To make use of the high speed they run it out at a shallow depth, and dive down on to the target (if it is a submerged submarine).
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It seems that at depth, Spearfish loses speed, while Mk 48 loses endurance.
Forest Green said:
It's 26km (14nm) at 80 knots and 56km (30nm) at 55 knots reading around the links on wiki. So back to 56km against a 25 knot target:
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Looks like 12.5nm at 80 knots (the 14 mile figure is statute miles), but that checks out. The corresponding figure for a Russian 65-76 torpedo, which can do 50km at 50 knots, is 27,300 yards. A more complete analysis would involve looking at no-escape zones, of course.

Interestingly, the crossover point between the two settings for Spearfish is 45 knots. Above that speed, the low-speed setting gives a longer engagement range; above it, the high-speed setting. The existence of such an extreme high-speed setting implies that the Royal Navy was concerned about targets (i.e. submarines) moving very quickly indeed. For the Mark 48, the corresponding speed is 21 knots.

On a slightly more absurd note, if you can get a 30 degree up angle on a Spearfish and broach the surface, it might reach an altitude of 70 feet or so. That's high enough to offer a theoretical anti-helicopter capability. Totally impractical, of course. But amusing to think about.
 

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