Re-arming the Leander frigates

[Rule of cool]

What's the go with using the Australian Ikara setup, with the launcher in the back corner? Is it the nuke depth charge thing?

 

[Scott Kenny]

I gotta disagree with @NOMISYRRUC about losing the VDS for refits.

A VDS is a very critical tool for a surface ship to chase submarines, because it lets you get your passive sonar down below the ~200ft thermocline. (Okay, it's usually a bit deeper than that, but that illustrates the point well enough)

Losing the VDS is a poor choice for a heavily ASW escort.

 

[starviking]

What's the go with using the Australian Ikara setup, with the launcher in the back corner? Is it the nuke depth charge thing?

I think that has been quoted as one factor, but I’d also guess that the North Atlantic could be rough on an installation there - so perhaps it was doubly damned?

 

[BlackBat242]

What's the go with using the Australian Ikara setup, with the launcher in the back corner? Is it the nuke depth charge thing?

Read this post from the first page of the thread you are reading: https://www.secretprojects.co.uk/threads/re-arming-the-leander-frigates.41294/post-590040

 

[BlackBat242]

I think that the RAN's type 12s could have been better modernized in the late 1970s - and here is how.

The only way I can see the RAN's Type 12s getting a better SAM system is either to mount a Sea Sparrow launcher atop the aft superstructure (in place of the Seacat) or to get the UK to go ahead with the 3-shot Sea Wolf launcher that had been intended to replace the Seacat 4-shot launcher 1-for-1 (not likely). A helo spot could be fitted if the Limbo is removed (as per Yarra in 1979-80) and a USN frigate-hangar (moderately short with a telescoping section that retracts into the fixed part of the hangar and is extended out when the helicopter is to be worked on or for inclement weather) could be fitted in place of the aft end of the superstructure (the spaces displaced could be fitted along the sides of the superstructure abreast of the funnel).

The helo for these modernized ships would have to be Lynx HAS.2s (deliveries from 1977 for the RN and other customers), with upgrades until the ships were decommissioned.

See this photo of HMS Yarra in 1984 to get the idea of my proposed modernization (the other 3 older ships would be the same):



Swan & Torrens would be similar:



Here is the RAN's Ikara layout:






USN small frigate hangar:

 

[Purpletrouble]

) or to get the UK to go ahead with the 3-shot Sea Wolf launcher that had been intended to replace the Seacat 4-shot launcher 1-for-1 (not likely).

My problem with all the “if only lightweight sea wolf launchers had been developed as planned” AHs that are promulgated is that aiui the problem with Sea Wolf wasnt the launchers - the sextuple things arent a significant issue in themselves (and likely to be lighter than the oft suggested 2x twin or trip or quad in their place) - but the directors and the below deck volume required for the computers.

Having served on T23s the tracker rooms are huge (some of the biggest spaces in the ship iirc) and dont encompass it all (and thats a developed SW). Post Sea Ceptor the freed up space has been a godsend given the other systems and general crampdness.

So for me the barrier to wider Sea Wolf adoption is not the launchers but the directors and computers - of which lighter/more efficient dont seem to ever be on the cards, and if they could have been, would have been evident in VLSW and T23.

 

[pathology_doc]

the problem with Sea Wolf wasnt the launchers - the sextuple things arent a significant issue in themselves (and likely to be lighter than the oft suggested 2x twin or trip or quad in their place) - but the directors and the below deck volume required for the computers.

Was Seacat ever developed to a true blindfire capacity? IIRC it got at least as far as semi-auto command to line of sight (keep the crosshair on the target and the guidance system does the steering), but I don't know if it ever made that last step. If it did, a faster airframe might have kept it competitive - knowing that you can't really put a Rapier system on a ship because the hit-to-kill nature of the weapon might not deal with incoming missiles well.

The problem with the Leanders IMHO is as with the EE Lightning; designed to too tight a spec with too little room for growth. A broad-beam Leander might have enough topweight allowance to take the compact Harpoon launch tube without losing its main guns, but was that even an option when the decision to fit missiles was taken?

 

[Rule of cool]

Its not in the spirit of the thread, but I wonder how things would have panned out if the Leanders were armed with the twin 3" guns that the Tigers got. Would that have given them more weight margin for growth? Would it and Sea Cat have been enough air defence so further upgrades could focus an AShMs?

 

[Scott Kenny]

The problem with the Leanders IMHO is as with the EE Lightning; designed to too tight a spec with too little room for growth. A broad-beam Leander might have enough topweight allowance to take the compact Harpoon launch tube without losing its main guns, but was that even an option when the decision to fit missiles was taken?

First Harpoon missiles delivered in 1977. So arguably not really an option when the upgrade was planned.

 

[Hood]

Its not in the spirit of the thread, but I wonder how things would have panned out if the Leanders were armed with the twin 3" guns that the Tigers got. Would that have given them more weight margin for growth? Would it and Sea Cat have been enough air defence so further upgrades could focus an AShMs?

A possibility but one thing that recurs during the mid-1950s though was that the Admiralty seemed to think that most small ships couldn't stow enough ammo to make the 3in L/70 a viable fit for AA use.

With both this thread and the Leander SAM thread, I've pondered that the big error might be the insistence on developing twin-gun mounts which ate up topweight, margin and required larger magazines. A single 4.5in mount or a single 3in L/70 might well have sufficed for frigates and - Vickers perhaps already had the ideal answer in the 4in Mk Q.

 

[Arjen]

The Dutch Van Speijk-class (modified Leanders) had their twin 4.5in mount replaced in 1976 by a single 76mm OTO Melara mount.

 

[Kanga]

I think that the RAN's type 12s could have been better modernized in the late 1970s - and here is how.

The only way I can see the RAN's Type 12s getting a better SAM system is either to mount a Sea Sparrow launcher atop the aft superstructure (in place of the Seacat) or to get the UK to go ahead with the 3-shot Sea Wolf launcher that had been intended to replace the Seacat 4-shot launcher 1-for-1 (not likely). A helo spot could be fitted if the Limbo is removed (as per Yarra in 1979-80) and a USN frigate-hangar (moderately short with a telescoping section that retracts into the fixed part of the hangar and is extended out when the helicopter is to be worked on or for inclement weather) could be fitted in place of the aft end of the superstructure (the spaces displaced could be fitted along the sides of the superstructure abreast of the funnel).

The helo for these modernized ships would have to be Lynx HAS.2s (deliveries from 1977 for the RN and other customers), with upgrades until the ships were decommissioned.

See this photo of HMS Yarra in 1984 to get the idea of my proposed modernization (the other 3 older ships would be the same):

View attachment 727526

Swan & Torrens would be similar:

View attachment 727527

Here is the RAN's Ikara layout:

View attachment 727528

View attachment 727529


USN small frigate hangar:

View attachment 727530


View attachment 727531

I don't think a nelicopter-equipped River would have retained Ikara. As I understand it, Ikara was developed because the RAN was dissatisfied with the helicopters capable of being carried on a Type 12; basically the Wasp. The Canadian's solution was Beartrap and Seakings on frigates. The RAN's solution was Ikara. As soon as capable frigate/ helicopter solutions became available, the RAN stopped fitting Ikara. For the same reasons I don't think the mooted Seaking-equipped County version for the RAN would have had Ikara either.
On another note, I was surprised to see it was the forward Limbo that was removed to accommodate the Ikara system. Never assume, as they say.
Edit: Reading an old Navy League article I see I was wrong and the RAN did want Ikara as well as helos on it's version of the Counties. However the helos would have been Wessex, not Sea King.

 

[MadRat]

How far along was Rapier at the time?

 

[zen]

How far along was Rapier at the time?

Needs a bigger warhead.

A single 3"/L70 could have been very useful and in development more could have been made of this.

 

[MadRat]

I'm pretty sure Rapier up to the late 80s was a hittile.

 

[Kanga]

Needs a bigger warhead.

A single 3"/L70 could have been very useful and in development more could have been made of this.

Or possibly the french 100mm? Not a Nato calibre but in service with a Nato navy (Hamburg class). Big enough (just) for naval gunfire support, to keep the army happy, but also with worthwhile AA capacity. Of course, that saves weight at the sharp end whereas you might want to save it down the blunt end.

 

[BlackBat242]

I don't think a nelicopter-equipped River would have retained Ikara. As I understand it, Ikara was developed because the RAN was dissatisfied with the helicopters capable of being carried on a Type 12; basically the Wasp. The Canadian's solution was Beartrap and Seakings on frigates. The RAN's solution was Ikara. As soon as capable frigate/ helicopter solutions became available, the RAN stopped fitting Ikara. For the same reasons I don't think the mooted Seaking-equipped County version for the RAN would have had Ikara either.
On another note, I was surprised to see it was the forward Limbo that was removed to accommodate the Ikara system. Never assume, as they say.

If modifications along the lines I suggest had been carried out, the helicopter carried would have been a Lynx (or possibly SH-2 Seasprite) - but as helicopters still are weather-restricted keeping Ikara (for a while) would merit strong consideration.

I do see, unless an improved Ikara airframe is developed that flew faster and or further is developed... then it might continue on.

Remember, Ikara was a rocket-powered remotely-piloted UAV carrying a small torpedo (US Mk 44 or Mk 46) which it dropped near the target before flying until running out of fuel (or the operator ditched it once far enough away from the drop zone), so there was room for improvement.

Removing Ikara could possibly allow enlarging both the halo landing deck and the hangar... but I cannot see 2 helos being carried.

 

[Scott Kenny]

If modifications along the lines I suggest had been carried out, the helicopter carried would have been a Lynx (or possibly SH-2 Seasprite) - but as helicopters still are weather-restricted keeping Ikara (for a while) would merit strong consideration.

I do see, unless an improved Ikara airframe is developed that flew faster and or further is developed... then it might continue on.

For the Aussies, yes. The Southern Ocean basically doesn't have anyone messing around in it, so the Aussies don't have the same push the UKRN does for an ASW weapon that works in weather bad enough to ground the helicopters.

Ikara had twice the range of the classic ASROC, but VL-ASROC reached the same range as Ikara. An Ikara Mod2 that had at least 50% more range than the Mod1 would be a good start. Making Ikara have twice the range of VL-ASROC would be quite a coup.

 

[pathology_doc]

Ikara had twice the range of the classic ASROC, but VL-ASROC reached the same range as Ikara.

Basic ASROC was unguided. Once it left the launcher, that was it; the heading could not be refined. Ikara could be steered the whole way. VL ASROC has some steering ability by definition, but I don't know whether this extends to midcourse guidance or only exists to put it on the right heading.

Besides, VL ASROC is from a completely different generation of development, so Ikara is doing well to keep up. I have no doubt that a completely redrawn Ikara with modern tech could do much better within the same platform dimensions (including retaining compatibility with the existing launcher).

 

[Hood]

There were a couple of proposed Ikara upgrades with additional range: M6 was stretched for a Stingray torpedo and had a modified Murawa boost/sustainer rocket for increased range, but was cancelled in 1976; M7 in the early 1980s was proposed with a turbojet sustainer.

 

[Kanga]

There were a couple of proposed Ikara upgrades with additional range: M6 was stretched for a Stingray torpedo and had a modified Murawa boost/sustainer rocket for increased range, but was cancelled in 1976; M7 in the early 1980s was proposed with a turbojet sustainer.

It's probably worth pointing out that the RAN's Seakings operating from HMAS Melbourne were modified to be able to control Ikaras after they were launched ( presumably so the helos could maintain sonar contact with the submarine). So Ikara was a good deal more flexible than ASROC.

 

[BlackBat242]

It's probably worth pointing out that the RAN's Seakings operating from HMAS Melbourne were modified to be able to control Ikaras after they were launched ( presumably so the helos could maintain sonar contact with the submarine). So Ikara was a good deal more flexible than ASROC.

Which is why I want to keep them as long as possible - preferably in an improved longer-ranged version.

The missile was a cruise type and attained a set altitude and was then steered over to a sonar contact where it dropped a Mk 44 or Mk 46 torpedo and then dived into the sea clear of the sonar range of the torpedo.

I see lots of room for performance increase even keeping the shape compatible with the existing launcher.







The missile was loaded rear-first.

 

[Purpletrouble]

Fwiw, I think the RN did about as well you can in rearming them, which reflects there just weren’t orher practical weapons then or earlier. The B1 Ikaras with VDS and helo were probably one of the best ASW ships out there, B2s I think a smaller gun + SSM a better fit (Mk8?) and B3s had the definitive Sea Wolf plus all could take towed arrays and the helo to act on it.

The Dutch ships were modernised a little later iirc, better than B2 refits definitely but still lacked any real air defence in comparison to RN broad beamed SW upgrades.

 

[Scott Kenny]

Fwiw, I think the RN did about as well you can in rearming them, which reflects there just weren’t orher practical weapons then or earlier. The B1 Ikaras with VDS and helo were probably one of the best ASW ships out there, B2s I think a smaller gun + SSM a better fit (Mk8?) and B3s had the definitive Sea Wolf plus all could take towed arrays and the helo to act on it.

The Dutch ships were modernised a little later iirc, better than B2 refits definitely but still lacked any real air defence in comparison to RN broad beamed SW upgrades.

Leanders are just too small. 360ft long. The US FFGs were at least 50ft longer.

I just don't see a way to give them a decent SAM and gun and AShM while keeping Ikara and the helicopter.

If there was somehow a way to stick a couple of Exocets into the Ikara launcher it'd help, but I suspect the launcher itself is too slow to point. The other option is to get the Exocets off the centerline and find a place to put them. On top of the hangar, maybe, with Seacat launchers port and starboard outboard of the Exocets?

 

[Purpletrouble]

Leanders are just too small. 360ft long. The US FFGs were at least 50ft longer.

They were whet they were, we in the UK seem obsessed on minimum size, long after comprehensive evidence that didnt help with cost, indeed made them worse.

I just don't see a way to give them a decent SAM and gun and AShM while keeping Ikara and the helicopter.

A decent SAM didnt exist until Sea Wolf and the below decks demand of that made it difficult - I still think the installation was very compromised anyway.

If there was somehow a way to stick a couple of Exocets into the Ikara launcher it'd help, but I suspect the launcher itself is too slow to point.

Very different weapons and sources - I dont think that’d be a goer.

The other option is to get the Exocets off the centerline and find a place to put them. On top of the hangar, maybe, with Seacat launchers port and starboard outboard of the Exocets?

Topweight probably. Didnt the B2s have to get their Excoets lowered at some point (maybe faulty memore!)

 

[norseman]

What about Crotale, was designed to be able to fit onto an armoured vehicle and the 8 round launcher fit smaller vessels. French but that didnt stop the adoption of Exocet? I vaguely remember talk of a naval 8 round Rapier as well which had compact electronics and a modified Blindfire radar though may have been a post it note doodle.

 

[TomS]

If there was somehow a way to stick a couple of Exocets into the Ikara launcher it'd help,

Better solution might be an antiship missile related to Ikara, which was in fact considered by the RAN. Possibly too late, and would have suffered from being a developmental effort; Exocet was at least off-the-shelf.

https://www.secretprojects.co.uk/threads/super-ikara.5504/post-143373

 

[zen]

Well there was Sea Killer and Sea Indigo .....Italian.

 

[uk 75]

Seacat 2 always seems to me a simple way of updating the widespread Seacat launchers in RN service with a better missile.
Phalanx after 1982 could have replaced Seacat launchers.
Harpoon replacing Exocets in the mid 80s would have been useful (8 rounds instead of 4).
RN Ikara seems to have been designed round the need to use a nuclear version.

 

[Purpletrouble]

Seacat 2 always seems to me a simple way of updating the widespread Seacat launchers in RN service with a better missile.

Presumably binned as “something even better is just around the corner”…

Phalanx after 1982 could have replaced Seacat launchers.

But was it really any better in its 1980s incarnation? It didnt help in 91 against that silkworm and its still a lot of cost and effort for ships then with literally a handful of years left.

Harpoon replacing Exocets in the mid 80s would have been useful (8 rounds instead of 4).

Again, a lot of cost and just how many things do you want to fling? You’ve got the exocets, they’re integrated and all is well. Exocet thanks to 82 has a good rep.

RN Ikara seems to have been designed round the need to use a nuclear version.

Yes, perhaps that’s the requirmeent to butterfly away and get a much cheaper/simpler and easier to integrate Ikara installation. Except I think this reflected the total lack of confidence in ASW torps (light and heavy), noting Tigerfish was also pretty much junk and even Spearfish took a while to mature. Didnt we drop a load of airborne types in 82 which didnt hit anything? In the Ikara design timeframe (late 60s?), the various 50s torpedo projects had all failed and we ended up buying US as a desperation measure not because they were especially good. Nuclear depth charges were I think seen as the only answer to deep diving SSNs.

The RAN didnt face that aiui, expecting diesal electrics from Indonesia/China.

Tbh, the more I learn about the reality of weapon systems post war, the more I think Sir Humphrey’s (defence budget purpose of) “It is to make people *believe* Britain is defended“ was absolutely spot on. It also makes one feel the treasury were right in opposing a lot of the expenditure.

 

[MadRat]

What about Crotale, was designed to be able to fit onto an armoured vehicle and the 8 round launcher fit smaller vessels. French but that didnt stop the adoption of Exocet? I vaguely remember talk of a naval 8 round Rapier as well which had compact electronics and a modified Blindfire radar though may have been a post it note doodle.

That actually was my first inclination but downgraded to Rapier as this ship class was so light in size and weak for power generation.

 

[Purpletrouble]

That actually was my first inclination but downgraded to Rapier as this ship class was so light in size and weak for power generation.

Does Crotale actually offer very much? I mean Sea Wolf struggled against the threats and that was a pretty high end system. “Lighter / simpler” to me means less capable and I think SW is a minimum.

Wasnt the Rapier blindfire/darkfire radar (something like it) actually part of the later SW upgrades anyway? I struggle to sea how the Rapier system could have been taken to sea without growing a lot of cost and complexity and weight to solve martime and integration issues SW had already faced.

 

[MadRat]

Blindfire was much more technically challenged than the original.

 

[Pioneer]

Wasnt the Rapier blindfire/darkfire radar (something like it) actually part of the later SW upgrades anyway? I struggle to sea how the Rapier system could have been taken to sea without growing a lot of cost and complexity and weight to solve martime and integration issues SW had already fafaced.i don't know mate

I don't know mate, a Tracked Rapier-like arrangement would appear to be quite compact and self contained....

(Sorry about poor quality of pics)

Regards
Pioneer

 

[Purpletrouble]

I don't know mate, a Tracked Rapier-like arrangement would appear to be quite compact and self contained....

(Sorry about poor quality of pics)

Regards
Pioneer

Not shipborne though or marinised, hence hasn’t faced the complexities SW had. Eg flex in alignments between launcher/director, movement of base platform (accounting for that in the guidance sw is huge) and having to operate/exist in very close proximity to many other powerful systems etc.

I think bits of Rapier was in SW anyway, sure one of its radars was part of 911, maybe optics also?

I spent a day in one of those a long while back, very capable radar and tracking optics matched to it as they’d replaced the launcher with cameras for trials support.

 

[Hood]

Harpoon replacing Exocets in the mid 80s would have been useful (8 rounds instead of 4).

All we had to do was upgrade to the MM.40 and we'd have had quad-tube launchers.
I suspect the decision to buy Harpoon was linked in with the Sub-Harpoon purchase and desire for a larger warhead.

But saying that, Sea Skuas from Lynxes caused far more devastation to enemy ships than RN ship-fired SSMs (even SS.12 from Wasps did too!).
Maybe all we need to really modernise Leander is an extending hangar, Lynx, Sea Skua, 76mm Super Rapid, Sea Sparrow and Stingray torps.

 

[A Tentative Fleet Plan]

Vickers perhaps already had the ideal answer in the 4in Mk Q.

Despite Peter Marland's love of that mounting, everything he writes about it seems to be pretty damning. Only 46 ready use rounds on mount, in other words less than a minute of firing, and when it ran dry it had to be loaded externally by an upper deck crew (not something you want to do in CBRN conditions). The mount could only fire one type of ammunition at a time, with no ability to switch to any other types, unless the mounting was unloaded and reloaded with a different type and it is unlikely that you could mix different types within the hoppers, much like a machine gun firing a mixture of tracer and ball, given the automatic fuse setters between the hoppers and loading tray.

 

[Hood]

Yes, it sounds like a new mounting would be required to meet the RN's needs, or at least a redesigned one.

 

[NOMISYRRUC]

I gotta disagree with @NOMISYRRUC about losing the VDS for refits.

A VDS is a very critical tool for a surface ship to chase submarines, because it lets you get your passive sonar down below the ~200ft thermocline. (Okay, it's usually a bit deeper than that, but that illustrates the point well enough)

Losing the VDS is a poor choice for a heavily ASW escort.

It may interest you to know that only 10 out of 26 Leanders had the Type 199 in the first place and the last 5 didn't have the VDS well.

This is a quote from Page 79 of "Royal Navy Frigates 1945-1983" by Leo Marriott.

The variable depth sonar was intended to be fitted in a well situated in the extreme stern of the ship. All vessels in the class (except the last five ― Scylla, Achilles, Diomede, Apollo and Ariadne) had the VDS well but only Leander, Dido, Aurora, Naiad, Arethusa, Cleopatra, Charybdis, Hermione, Jupiter and Bacchante were actually equipped with the sonar gear.

And later in the same paragraph it says . . .

However, he resulting equipment was difficult to handle and operate, and was not of much use in areas of relatively shallow water such as the North Sea and British coastal waters. For these reasons the equipment was not fitted to all of the class.

Of the 10 out of 26 ships that had the Type 199 fitted 6 were Batch 1s (Leander, Dido, Aurora, Naiad, Arethusa & Cleopatra) and four were Batch 3s (Charybdis, Hermione, Jupiter & Bacchante).

Leander, Dido, Aurora, Naiad, & Arethusa had the "Ikara" modernisation while Cleopatra had an "Exocet" modernisation and Charybdis, Hermione & Jupiter had the "Sea Wolf" modernisation. The last 4 in that list had their Type 199s and Limbo mortars removed, but they also had their hangars and flight decks extended so they could operate the Lynx helicopter instead of the Wasp.

 

[EwenS]

Then in the 1980s the following Leanders were given the Type 2031 towed array passive sonar mounted on the starboard quarter.

Batch 1 Ikara - Arethusa (2/86)
Batch 2 Exocet - Phoebe (7/82), Cleopatra (4/83), Argonaut (11/83), Sirius (12/85)

The Exocet ships gave up the Seacat launcher on the bow as weight compensation. This is Argonaut.