Sea Slug

[CJGibson]

I wasn't referring to a design team or time-spans.

It is easy to criticise decisions taken 70 years ago knowing what we know now. Far too much of that going on for my liking.
'Sea Slug was rubbish.' Maybe so, and an easy statement to make, but if it's what you have, and all you're likely to get, as they say in rugby, 'Use it'. We did and a very useful experience it proved to be.

Back to my supplementary question. How many SAM/SAGW projects were ongoing in the US in 1949 and 1960? I'll even narrow it down to naval SAMs.

Chris

 

[Dilandu]

People at Convair Pomona who developed the Terrier worked in the same time-span.

And how does early Terrier systems look like?


Ooops, exactly as "Sea Slug". Long hangar-type magazine, missiles on pallets, manual finning before launch... What an unwieldy system!

P.S. As I mentioned above, "Terrier" was purely accidental. It was born out as by-product of "Bumblebee" program - merely a test rocket (CTV-8 Supersonic Test Vehicle) for radar guidance system testing. It could very easily not be created at all - Applied Physics Lab could, for example, decide to make a liquid-fuel test rocket on nitric acid. And then there would be no "Terrier": only "Talos" and gun-launched "Zeus" for quite a long time.

 

[Tzoli]

Could this be considered a Drum stowage?

 

[CJGibson]

Hmmmm...interesting...(strokes beard, contrary to government advice)...I wonder if AWA got their idea from Pomona....and simplified it.

Chris

 

[Grey Havoc]

One historical irony was that Zeus was not put into service because the USN thought that Talos (which they initially believed would make shorter range AA weapons unnecessary, saving what were in the late 1940s scarce funds) would be in service much sooner, not to mention the school of thought within the navy that held guns were obsolete altogether. Needless to say, fallacy upon fallacy.

EDIT: Link to the SAM-N-8 Zeus thread for those who may not be familiar with this weapon.

 

[Dilandu]

Count the number of missiles... IIRC should be 62.
The arrangement shown above is the one-level Mk-9 designed for CL-conversions, the CLG-6 Providence-class, where it was essential to have a non-deck penetrating design in order to reduce the conversion costs.

And now try to put the same arrangement on a "County"-class ship; which was nearly three times smaller than "Providence".

BTW in a reduced length scheme, it even fit on a Gearing-class destroyer hull (USS Gyatt DD-712, DDG-1);

Yeah, and how many missiles fit on "Gyatt"?

Fourteen.

try this with your SeaSlug!

Easily. The original SeaSlug magazine arrangement were supposed to look like that:



You seems to fail to understood, that the peculiar magazine arrangement on "County"-class was not the demand of missile design. It was the demand of ship's survivability. The "County" magazines were distributed along the ship's axis; thus they were better protected, and there weren't risk that one hit would took out all ship's missile supply.

There were zero technical reasons why SeaSlug assembly could not be made more compact. It's just that on "County"-class the matters of ship survival were put ahead.

 

[Jemiba]

A reminder to all of us :
Please avoid overquoting ! It makes reading such posts sheer torture and quite probably you cannot be sure,
that the content between the quotes really gets through. So, it's of no use for anybody.

 

[uk 75]

At the risk of repeating myself, the comparison between Seaslug1 and Terrier is pretty much even, perhaps with Seaslug being a shade better.
The question I want to resolve is the comparison in the 70s between Seaslug 2, Masurca and Standard ER. At first sight, the advantage lies clearly with Standard ER, but ?
Similarly Seadart is competing not with Tartar but Standard MR on Perrys, Kidds etc

 

[Dilandu]

The question I want to resolve is the comparison in the 70s between Seaslug 2, Masurca and Standard ER.

Seaslug 2 was far less capable than either Masurca or Standard. It was still a beam-riding missile (albeit quite a good one), with old-fashioned magazine system.

It was probably possible to continue Seaslug developement, so it would be able to compete with Masurca and late-generation Terriers, but Royal Navy simply did not see much reasons to do that - they already decided to switch to Sea Dart.

 

[uk 75]

Thank you Dilandu.
As this thread is about Seaslug I think it is important to say that Seaslug 2 was intended to introduce similar improvements to Standard RIM67A ER on Coontz and other US ships.
This should have been well within UK capabilities at the time. But we dont seem to be able to find out whether Seaslug 2 worked or not?
If it had, the gap until Seadart took over fully in the 80s would not have been so serious.
Discussion of Seadart vs Standard MR deserves a separate new thread

 

[Tzoli]

Found a rare footage of HMS Girdle Ness firing and then intercepting a drone target with it's Sea Slug!

 

[Dilandu]

This should have been well within UK capabilities at the time. But we dont seem to be able to find out whether Seaslug 2 worked or not?

There are seems to be some kind of confusion here: I though you were talking about Seaslug Mk2? It obviously worked.

 

[Dilandu]

Found a rare footage of HMS Girdle Ness firing and then intercepting a drone target with it's Sea Slug!

Very interesting! Hm, why so much smoke while missile is still on the launcher? Is that the liquid-fuel prototype?

 

[Zoo Tycoon]

The pre-launch smoke I suspect is coming from a pyro used to spin the gyro’s up. Quite common on the early generation SAM’s.

 

[Zoo Tycoon]

As for whether the mk2 achieved service release see posts 25 and 68 on this thread;- These are authoritative answers.

Whilst I appreciate there’s quite a bit of inaccurate information in the media, I’ve always noticed the quoted SSKP is always less for the mk2 than the mk1. This is counter intuitive for what’s norm as generally you evolve to improve. Maybe this is the source of the story.

 

[uk 75]

My apologies to SeaslugMk2. His site is indeed very comprehensive and covers the points.
Given this, I accept that compared with other European countries (France with its Suffrens and Colbert and Italy with its Dorias and Veneto) the UK did well to get 8 Countys to seas by the beginning of the 70s. Unlike the USA we had financial and other bottlenecks to contend with.
It could also be argued that the delay in deploying Seadart was due to the evolution in its capabilities which came to match the Standard MR and possibly better in some respects.
Whatever, the RN did manage to be the only Western Navy outside the US to have a significant area missile anti air capability. Japan despite its great resources only started to have ships in numbers with Standard MR by the late 80s.
My favourite Seaslug moment remains the footage in Gerry Anderson's UFO when a County engages (using the footage from the public info film above)

 

[Maury Markowitz]

This isn't a thread about Sea Dart or Talos. I'm sure there are appropriate threads on them.

I was replying to a post about "...you can fit a polyrod (Sea Dart like) SARH guidance to a Sea Slug like missile." Who was that? Oh, it was you!

 

[zen]

This isn't a thread about Sea Dart or Talos. I'm sure there are appropriate threads on them.

I was replying to a post about "...you can fit a polyrod (Sea Dart like) SARH guidance to a Sea Slug like missile." Who was that? Oh, it was you!

Stating what could be done to upgrade the Sea Slug system and ships armed with it. Context.

 

[SeaslugMk2]

As for whether the mk2 achieved service release see posts 25 and 68 on this thread;- These are authoritative answers.

Whilst I appreciate there’s quite a bit of inaccurate information in the media, I’ve always noticed the quoted SSKP is always less for the mk2 than the mk1. This is counter intuitive for what’s norm as generally you evolve to improve. Maybe this is the source of the story.

Well, the quote of 92% for Seaslug Mk1 is complete fiction.
From the 69 firing reports for Seaslug Mk2 that I had access to I calculated an overall success rate of about 63%; unfortunately all the documentation for the Mk1 missile was destroyed after HMS London was sold. I have found only one firing report and that seems to have been preserved by accident. I was allowed sight of a file created by a senior technician at AWA which summarised the results of Mk1 firings in order to analise the causes of failures, but I wasn't even allowed to make notes much less copy it. I did, however, tot up the fails and successes which showed a success rate of about 75%.
I would also say that the targets of the Mk1 firings were slower and all at medium to high altitudes -which is what it had been designed to deal with.
Mk2 targets were at a greater range of speeds (up to M1.8) and at altitudes down to 100 feet.

SRJ.

 

[uk 75]

I was told in 1972 as an RAF CCF cadet at school when we went on Kent that Seaslug Mk1 performed better than Terrier or Tartar.
This was as we leaving Portsmouth and I had asked our escorting crewmember why a visiting Adams class destroyer had a neat looking launcher and the RN had all "this scaffolding" pointing to the Seaslug launcher.
As a little "crab" I was risking it. But we actually got to see the assmbly magazine. The RN looked after us very well.

 

[pathology_doc]

My favourite Seaslug moment remains the footage in Gerry Anderson's UFO when a County engages (using the footage from the public info film above)

Hilariously, when he switches to guns after the missiles foul up, the main gun turret looks suspiciously like that of Lion, Tiger or Blake.

 

[SeaslugMk2]

You are right Pathology_doc, the film used is an amalgam of two official films. One is about the County class and the other is a general film about the RN and they've taken segments of one of the cruisers firing its guns. There is another official film -Action Navy- which has a segment on one of the second batch (ie a Mk2 armed ship) which is good, but it still uses part of the film of HMS Devonshire's clearance trials for the missile firing!

 

[fishpond]

Anyway comparaison is in order here. Counties were nice ships, aesthetically speaking, but Sea Slug was a complete engineering disaster. Those monstrous missile, magazine, launcher, director had a tremendous ship-impact while having a limited performance. Makes really one wonder why the English did not give it up and move to RIM-8 Talos, like they did in many other areas at that time: C-130 instead of AW.681, F-111 instead of TSR.2, F-4 instead of P.1154, S-55, S-58 and S-61 instead of local helicopters, Little John / Lance instead of Blue Water, Skybolt then Polaris instead of Blue Streak and Blue Steel, Sea Mauler instead of what-ever, US nuclear weapon designs instead of theirs, W33 and M110, W48 and M109, instead of Tony for their own artillery, etc. Perhaps was it because under the naval version of Project E, RIM-8 D Talos with W30 nuclear warhead, the most desirable combination, would have necessitated a Marines detachment and a senior USN officer on board their ships in order to implement the safeguarding and double-key provisions, something a little bit difficult to swallow for them?

 

[fishpond]

I had understood that Seaslug got the wrap-around boosters because Farnborough (?) thought that tandem boosters would be vulnerable to shock. My impression is that by about 1959, when what became Sea Dart was being proposed, many in the British defense bureaucracy were heartily sick of the high developmental cost and delay associated with Seaslug, and wanted something -- anything -- else. Sea Dart was pushed as something entirely different, not a Seaslug replacement (which it was). As for Talos, the RN did consider it for the cruisers, but it was far too massive for a DLG. It wasn't just a big missile, it required a lot of radar, too. I think the main lesson of the Seaslug-Sea Dart story is that the RN would have been much better off if it had followed an evolutionary path, say to a Seaslug with a better rocket motor (as in Standard), and also to semi-active guidance. That was certainly the U.S. experience: Terrier to Tartar to Standard, with lots of the money going into fire control. It did not help that the Admiralty insisted on cutting the size of the Seaslug ship because it equated size with cost -- the designers were aware that everyone else's missile ships were rather larger.

 

[Zoo Tycoon]

I think the wrap around booster came from the technology limit on the early solid fuel SFC, which If used as a tandem would increase the missile length substantially and hence have dire consequences for storage/handling. Talos pushed the booster SFC technology but ran into the significance combustible stability problems fixed by the introduce burn rate stabilisation sticks into the propellant. Sea Dart’s booster was the next generation on again and was a very challenging development, This delivered a compact booster which would have been considered science fiction at the start of Sea Slugs development.

Sea Dart really was an evolution of Sea Slug albeit to a different specification because it was developed by the same engineering team at AWA (later HSD) Whitley/RAE/RARDE/RSRE/ASWE. They took all they had learned and yielded a far more compact/capable system. The loss to the industry was not following on from Sea Dart because once the team was disbanded, the deep learning, continuity, and basic development network ceases to exist.

Another point is starting with a physical small system, with limited capability and expanding capability as technology improves is a good long term evolution approach. Whereas starting with a physical large system and trying to shrink its bulk within a capability as technology improves is a non starter.

 

[Dilandu]

If I recall correctly, one of the reason was, that the wrap around scheme allowed for simpler manual handling of the missile in case of battle damage - "Sea Slug" could, at least theoretically, be rolled on man-pushed trolley and loaded into the launcher even with the loss of electric power in magazine (assuming, of course, that FC radar is still working). For "Terrier" it would be literally impossible to reload it manually.

 

[uk 75]

In fairness to the UK designers the Seaslug was probably more robust and effective than the early Terriers.
The Countys give the UK ships that are impressive. They influenced US designers for the Spruance.
No other European navy builds a comparable class of ship. Italy's three helicopter cruisers and France's two Suffrens are the only similar ships.
Seadart is designed for a smaller ship. The USN goes the same route with its Perry class.
Like big aircraft carriers, missile cruisers use too much manpower and resources for the strapped RN. CVA 01 and couple of 1962 Escort Cruisers would have hollowed out the RN much like the 2 CVFs. In the words of Dirty Harry Callaghan " a man has to know his limitations"

 

[TomS]

Seadart is designed for a smaller ship. The USN goes the same route with its Perry class.

I wouldn't equate Sea Dart with the SM-1 in the Perrys. The Perrys had very limited combat systems and were not really regarded as area defense platforms. They had only one really robust channel of fire for Standard plus a limited one via the gun fire control, and no 3-d radar, which meant they used their fire control radar as a heightfinder. In many ways, the USN saw the SM-1 on the FFGs as a solution to the same basic requirement as the Sea Wolf on the Type 22s, a counter to submarine-launched popup ASCMs appearing inside the area air defense perimeter able to defend ownship and possibly one or two ships in close company.

 

[uk 75]

TomS Agreed. The T42 design did start off being rather basic like the FG109s but the in service version had a twin arm and twin director config.
My only aim in drawing parallels with the USN is to reflect the very close relationship between it and the RN which was a two way street. The introduction of the T missiles threw up many problems and the RN learnt from this in its work on its own missiles.
NATO's Standing Naval Force Atlantic (SNFL) was an opportunity for both to compare their respective systems at sea

 

[Volkodav]

Interesting topic, thank you.

I find the County Class particularly interesting as a family friend who served on and loved the Perth (Adams) Class DDGs, made the point that the RAN would have been far better served by a modified County design. My apologies if I drift too far off topic.

Reading through a number of points caught my attention, and reminded me of other readings I have done on the subject :
- Seaslug MkI was comparable (if not superior) to earlier variants of Terrier.
- Seaslug MkII was inferior to late model Terrier and Standard SM-1, but was necessary as the RN needed the additional ships but nothing else practicable (palatable) was available.
- A number of European Navies concurrently operated converted and new build ships with Terrier (or equivalent), with converted and new build ships with Tartar.
- Seadart was superior to Standard SM-1 but not SM-2 (not really comparable as it was only available on AEGIS platforms until the advent of NTU in the mid/late 80s)
- 10 Counties were planned, 4 Batch 1, and 2 + 2 Batch 2 were completed, with orders being placed for pairs in 1956, 57, 61 and 65.
- The 7th and 8th Counties were delayed and the 9th and 10th were cancelled because the RN expected to be ordering Escort Cruisers
- The Escort Cruisers are not ordered and the RN ended up converting Tiger class cruisers instead (not satisfactory as lower helo capacity, no area air defence capability, large crew)

Then there is the RAN interest in a Tartar armed County:
- The RAN had a totally unrealistic expectation that a steam only, Tartar armed derivative of the County could also carry 3 Wessex, with a displacement of 4000tons.
- The RN informed them this was not possible and recommended they adopt the standard County design, or wait for the Escort Cruiser that actually better suited their requirements
- The RANs preference for Tartar has been reported to relate to the poor performance of Seaslug in trials at Woomera, also planned to fit Tartar to Battle and Daring Class destroyers
- The RN said they did not have the design capacity to develop a Tartar County with improved aviation facilities, private yards said they did.

Piecing this all together, the Batch 1 Counties and Seaslug Mk I make perfect sense, even qualify as good value, but the Batch 2 and Seaslug MkII less so. It really is too bad the RN didn't compromise with the RAN and meet them halfway with a Tartar County redesign. Basic hull and machinery design retained, SeaSlug deleted, Mk 13 GMLS in place of B turret, helicopter deck extended aft, hangar redesigned for three Wessex or two SeaKing (maybe three SeaKing), Seacat (if retained) moved to hangar roof. Seaslug magazine repurposed for aviation stores, fuel etc. Maybe even look at an RAN style Ikara installation aft of the helo deck. The RN could order four to six Tartar Counties instead of the Batch II Counties and the Tiger conversions (sell the Tigers to ABC instead). Best of all, by the time these ships are ordered the RN would have an idea of the dimensions and integration requirements of the future Seadart system and have completed the Tartar County redesign with the facility (for the design, not necessarily the already built ships) to be easily adapted to Seadart.

Perhaps with the money, time and effort saved by stopping the original Seaslug Mk II development, resources could be applied to developing meaningful improvements to Seaslug Mk1 that could be retrofitted to the Batch 1 ships.

 

[zen]

Interesting topic, thank you.

I find the County Class particularly interesting as a family friend who served on and loved the Perth (Adams) Class DDGs, made the point that the RAN would have been far better served by a modified County design. My apologies if I drift too far off topic.

Reading through a number of points caught my attention, and reminded me of other readings I have done on the subject :
- Seaslug MkI was comparable (if not superior) to earlier variants of Terrier.
- Seaslug MkII was inferior to late model Terrier and Standard SM-1, but was necessary as the RN needed the additional ships but nothing else practicable (palatable) was available.
- A number of European Navies concurrently operated converted and new build ships with Terrier (or equivalent), with converted and new build ships with Tartar.
- Seadart was superior to Standard SM-1 but not SM-2 (not really comparable as it was only available on AEGIS platforms until the advent of NTU in the mid/late 80s)
- 10 Counties were planned, 4 Batch 1, and 2 + 2 Batch 2 were completed, with orders being placed for pairs in 1956, 57, 61 and 65.
- The 7th and 8th Counties were delayed and the 9th and 10th were cancelled because the RN expected to be ordering Escort Cruisers
- The Escort Cruisers are not ordered and the RN ended up converting Tiger class cruisers instead (not satisfactory as lower helo capacity, no area air defence capability, large crew)

Then there is the RAN interest in a Tartar armed County:
- The RAN had a totally unrealistic expectation that a steam only, Tartar armed derivative of the County could also carry 3 Wessex, with a displacement of 4000tons.
- The RN informed them this was not possible and recommended they adopt the standard County design, or wait for the Escort Cruiser that actually better suited their requirements
- The RANs preference for Tartar has been reported to relate to the poor performance of Seaslug in trials at Woomera, also planned to fit Tartar to Battle and Daring Class destroyers
- The RN said they did not have the design capacity to develop a Tartar County with improved aviation facilities, private yards said they did.

Piecing this all together, the Batch 1 Counties and Seaslug Mk I make perfect sense, even qualify as good value, but the Batch 2 and Seaslug MkII less so. It really is too bad the RN didn't compromise with the RAN and meet them halfway with a Tartar County redesign. Basic hull and machinery design retained, SeaSlug deleted, Mk 13 GMLS in place of B turret, helicopter deck extended aft, hangar redesigned for three Wessex or two SeaKing (maybe three SeaKing), Seacat (if retained) moved to hangar roof. Seaslug magazine repurposed for aviation stores, fuel etc. Maybe even look at an RAN style Ikara installation aft of the helo deck. The RN could order four to six Tartar Counties instead of the Batch II Counties and the Tiger conversions (sell the Tigers to ABC instead). Best of all, by the time these ships are ordered the RN would have an idea of the dimensions and integration requirements of the future Seadart system and have completed the Tartar County redesign with the facility (for the design, not necessarily the already built ships) to be easily adapted to Seadart.

Perhaps with the money, time and effort saved by stopping the original Seaslug Mk II development, resources could be applied to developing meaningful improvements to Seaslug Mk1 that could be retrofitted to the Batch 1 ships.

You know I was guilty of this in the past and now I realise how it detracts from the subject.
This properly Alternative History.
And the central theme is AH County, with Tartar.

So not really about Sea Slug is it.....
So I'd advise doing an AH thread about this if you like.

I'll even try to contribute if I can.

 

[Volkodav]

Interesting topic, thank you.

I find the County Class particularly interesting as a family friend who served on and loved the Perth (Adams) Class DDGs, made the point that the RAN would have been far better served by a modified County design. My apologies if I drift too far off topic.

Reading through a number of points caught my attention, and reminded me of other readings I have done on the subject :
- Seaslug MkI was comparable (if not superior) to earlier variants of Terrier.
- Seaslug MkII was inferior to late model Terrier and Standard SM-1, but was necessary as the RN needed the additional ships but nothing else practicable (palatable) was available.
- A number of European Navies concurrently operated converted and new build ships with Terrier (or equivalent), with converted and new build ships with Tartar.
- Seadart was superior to Standard SM-1 but not SM-2 (not really comparable as it was only available on AEGIS platforms until the advent of NTU in the mid/late 80s)
- 10 Counties were planned, 4 Batch 1, and 2 + 2 Batch 2 were completed, with orders being placed for pairs in 1956, 57, 61 and 65.
- The 7th and 8th Counties were delayed and the 9th and 10th were cancelled because the RN expected to be ordering Escort Cruisers
- The Escort Cruisers are not ordered and the RN ended up converting Tiger class cruisers instead (not satisfactory as lower helo capacity, no area air defence capability, large crew)

Then there is the RAN interest in a Tartar armed County:
- The RAN had a totally unrealistic expectation that a steam only, Tartar armed derivative of the County could also carry 3 Wessex, with a displacement of 4000tons.
- The RN informed them this was not possible and recommended they adopt the standard County design, or wait for the Escort Cruiser that actually better suited their requirements
- The RANs preference for Tartar has been reported to relate to the poor performance of Seaslug in trials at Woomera, also planned to fit Tartar to Battle and Daring Class destroyers
- The RN said they did not have the design capacity to develop a Tartar County with improved aviation facilities, private yards said they did.

Piecing this all together, the Batch 1 Counties and Seaslug Mk I make perfect sense, even qualify as good value, but the Batch 2 and Seaslug MkII less so. It really is too bad the RN didn't compromise with the RAN and meet them halfway with a Tartar County redesign. Basic hull and machinery design retained, SeaSlug deleted, Mk 13 GMLS in place of B turret, helicopter deck extended aft, hangar redesigned for three Wessex or two SeaKing (maybe three SeaKing), Seacat (if retained) moved to hangar roof. Seaslug magazine repurposed for aviation stores, fuel etc. Maybe even look at an RAN style Ikara installation aft of the helo deck. The RN could order four to six Tartar Counties instead of the Batch II Counties and the Tiger conversions (sell the Tigers to ABC instead). Best of all, by the time these ships are ordered the RN would have an idea of the dimensions and integration requirements of the future Seadart system and have completed the Tartar County redesign with the facility (for the design, not necessarily the already built ships) to be easily adapted to Seadart.

Perhaps with the money, time and effort saved by stopping the original Seaslug Mk II development, resources could be applied to developing meaningful improvements to Seaslug Mk1 that could be retrofitted to the Batch 1 ships.

You know I was guilty of this in the past and now I realise how it detracts from the subject.
This properly Alternative History.
And the central theme is AH County, with Tartar.

So not really about Sea Slug is it.....
So I'd advise doing an AH thread about this if you like.

I'll even try to contribute if I can.

Yes sorry about that, I was basically putting my thoughts down in bullet point when I realised I was going too far off topic. In a nutshell, the Batch 1 and Seaslug Mk1 were probably the best option for the RN at the time they were ordered and entered service, the issue was the failure to develop sufficient enhancements that could be incorporated in the Seaslug system envelope and on board the County Class platform. The development of the Mk2 and it apparently not being easily incorporated in the Batch 1 ships was a strange failing as the US managed to fit a totally new missile in the basic form of the existing Tartar and Terrier, ensuring it could be fitted to all existing platforms with appropriate CS upgrade.

Many who lorded the USN missiles and slam the Seaslug don't seem to realise just how different, not just the missile, but the sensors and combat systems retro fitted to the early Tartar and Terrier ships were to the initial baseline. There is a paper by the former Chief of the RAN, on the effects of the adoption of the Adams Class DDGs had on the RAN that highlights just how challenging and expensive it was to get the supposedly "turn key" Adams class to just work, then to upgrade them. Thinking on it there are some interesting refernces in the paper about SeaSlug as well.

The Adams-class guided-missile destroyers and the RAN | The Strategist

From its origins in 1901 until the late 1950s, through its deep association with the Royal Navy, the Royal Australian Navy became unmistakably British in outlook, practices and culture. It was a relationship of great ...

www.aspistrategist.org.au

 

[Zoo Tycoon]

According to S Twigg’s paper in Cold War Hot Science, page 111, Sea Slug’s development cost was thirty times the original estimate. It was also credited with saving AWA Coventry from closure....until that is, until the late 60’s.

 

[CNH]

Sea Slug’s development cost was thirty times the original estimate.

So what's new?

 

[Tzoli]

Weren't there ideas to further update the Seaslug missile (to Mk III ? ) to be a non beam riding missile? So it could use the more modern and probably smaller radars and fully exploit the twin launcher capability?

 

[SeaslugMk2]

I have full details of 68 Seaslug firings, and partial details of a further 36; for this study I have initially taken the former set. Of these 68, six were declared 'no test'; for reasons such as the telemetry transmitter failing, or the destruction of the target because the Range Safety Officer believed (incorrectly, as it turned out) that it was about to fly beyond the range safety limit. Of the remaining 62 firings 25 were classed as unsuccessful and 37 as successful, this gives an overall success rate of 59·7%.
If, however, we separate those firings at targets below 1000 feet the picture changes. For targets above 1000 feet there were 35 successful firings out of 54, and below 1000 feet just 2 successful out of 8. This gives a success rate of 64·8% for the former, and just 25% for those below 1000 feet.

One fascinating fact that emerged from this assessment it that the missile physically struck the target on no less than 6 occasions -effectively 10% of overall firings- at ranges up to 34,500 yards and at an altitude of 53,500 feet; and also as low as 80 feet!

I have attached a PDF copy of part of my working spreadsheet; comments are welcome.

SRJ.

Edited twice; once to correct an error and secondly to add the file.

 

[pathology_doc]

Of the remaining 62 firings 25 were classed as unsuccessful and 37 as successful,

Out of interest, what is the definition of a successful firing? Destruction of the target is of course unequivocal, but were there "softer" criteria in some or all of the firings? Inquiring minds want to know what they were looking for and why they were looking for it.

(I remember reading a case of a Fireflash ripping its wings off when the boosters separated, but the control actuators still steering it to a kill. Success and failure in the one shot!)

In other words, are these all live firing practice, or do they include experimental and/or development shots?

 

[uk 75]

Does any.material exist describing what.Seaslugs were expected to be fired at?
Initially.Il28 light bombers and Tu16s?
Would a County destroyer be expected to shoot down Migs and Sukhois?
Soviet.stand off missiles were like small jet aircraft well into the 70s.

 

[SeaslugMk2]

A success was defined as the fuze triggering (or command detonation signal received) at the right time for the warhead to inflict sufficient damage to cause the target to break up within 15 seconds -the F(15) definition. The US had a series of softer effects; ie forced to abort the attack, down to suffering damage on landing but these were regarded as irrelevant by UK missile development teams.
Expected targets would have been trans-sonic bombers of the fifties and sixties for Mk1, and attack aircraft and missiles of the sixties and seventies for Mk2.
These were the practice shoots by the ships once 'in service' and are not part of the development of the missile.
I hope to have some more data soon.

SRJ.

 

[zen]

A success was defined as the fuze triggering (or command detonation signal received) at the right time for the warhead to inflict sufficient damage to cause the target to break up within 15 seconds -the F(15) definition. The US had a series of softer effects; ie forced to abort the attack, down to suffering damage on landing but these were regarded as irrelevant by UK missile development teams.
Expected targets would have been trans-sonic bombers of the fifties and sixties for Mk1, and attack aircraft and missiles of the sixties and seventies for Mk2.
These were the practice shoots by the ships once 'in service' and are not part of the development of the missile.
I hope to have some more data soon.

SRJ.

Right there is one of the major differences between US and UK perspectives on systems like this.