Updating Seaslug

GK Dundas said:
Makes you wonder just how many Sea Darts you could manage to place into a magazine designed to hold Sea Slugs ..
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It's complicated. The main limiting factor is a wingspan, since Seaslug magazine is long and narrow. The Seaslug have 1.4 meters wingspan; the Sea Dart have circa 1 meter wingspan. So basically in space filled with two Seaslugs side-by-side you could put no more than two Sea Darts. Since the Sea Dart launcher is two-rail, it's pointless to try and fit the third missile in width.

Length, however, is more promising. The Sea Dart is about 30% shorter than Seaslug. So in place of two Seaslug missiles one after another you could put three Sea Dart missiles. So you could put about 36 Sea Dart missiles in the place, filled with 24 Seaslug missiles in ready-use magazine.

If we won't limit themselves with ready use magazine only (and we have no reason to - the Sea Dart is stored only completed, and did not require onboard checks, so we could utilize both the checkout area and long-term storage magazine from Seaslug) then we could double the number of missiles stored, and put probably as much as 72 Sea Dart missiles in Seaslug magazine space.
 
Dilandu said:
It's complicated. The main limiting factor is a wingspan, since Seaslug magazine is long and narrow. The Seaslug have 1.4 meters wingspan; the Sea Dart have circa 1 meter wingspan. So basically in space filled with two Seaslugs side-by-side you could put no more than two Sea Darts. Since the Sea Dart launcher is two-rail, it's pointless to try and fit the third missile in width.

Length, however, is more promising. The Sea Dart is about 30% shorter than Seaslug. So in place of two Seaslug missiles one after another you could put three Sea Dart missiles. So you could put about 36 Sea Dart missiles in the place, filled with 24 Seaslug missiles in ready-use magazine.

If we won't limit themselves with ready use magazine only (and we have no reason to - the Sea Dart is stored only completed, and did not require onboard checks, so we could utilize both the checkout area and long-term storage magazine from Seaslug) then we could double the number of missiles stored, and put probably as much as 72 Sea Dart missiles in Seaslug magazine space.
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is this an appropriate place for a "Muahahahaahaha"? 'Cuz it feels like one
 
It was Sea Slug that couldn’t be stored vertical rather than Sea Dart not being stored horizontal. A vertically stored Sea Slug would require a very deep magazine making or an unacceptable freeboard. A Booster added to its back end would just make the problem worse. The wrap around booster were a very poor arrangement with most of the booster thrust required simply to overcome it’s own drag. Additionally the layout of the missile’s internal components was compromised around placing guidance aerials at the rear…. did you know it had a flame suppressor system to extinguish any residual burning of the motor so the combustion products wouldn’t interfere with the beam it required for guidance. Hence to update would have pretty much stripped everything out of the aero shell, to start again, in an overall architecture that was too large for anything other than a purpose designed ship. Not a promising foundation when compared to a system intended to be easily installed in new ship architectures.

I once asked the head of flying controls at Warton why the TSR2 long, slim fuselage/ blown highly loaded blown wing was never done again. He replied that “the key thing we learned was it was way more difficult originally thought and in the end was not that competitive ”…. Then he added “and of course the reason why we’re not going to do another swing wing was because the key learning was it was way more difficult and in the end not good enough to compete with the competition ”… sometimes you’ve just got to move on.
 
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Zoo Tycoon said:
Additionally the layout of the missile’s internal components was compromised around placing guidance aerials at the rear…. did you know it had a flame suppressor system to extinguish any residual burning of the motor so the combustion products wouldn’t interfere with the beam it required for guidance. Hence to update would have pretty much stripped everything out of the aero shell, to start again, in an overall architecture that was too large for anything other than a purpose designed ship. Not a promising foundation when compared to a system intended to be easily installed in new ship architectures.
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Well, the more reason for the homing version, then - the polyrod interferometer antenna would not require major internal rearrangement, and would not be concerned with motor flame (so we could install longer-burning motor and increase range significantly).
 
Dilandu said:
If we won't limit themselves with ready use magazine only (and we have no reason to - the Sea Dart is stored only completed, and did not require onboard checks, so we could utilize both the checkout area and long-term storage magazine from Seaslug) then we could double the number of missiles stored, and put probably as much as 72 Sea Dart missiles in Seaslug magazine space.
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I suspect that any attempt to get over 36 missiles would involve some kind of additional protection to sub-divide the tunnel. This isn't just for protection against incoming warheads and shrapnel, the RN was paranoid about an accidental rocket motor firing igniting the missiles behind it - which is why they went for deeper rather than longer Ikara magazines.
 
Hood said:
I suspect that any attempt to get over 36 missiles would involve some kind of additional protection to sub-divide the tunnel. This isn't just for protection against incoming warheads and shrapnel, the RN was paranoid about an accidental rocket motor firing igniting the missiles behind it - which is why they went for deeper rather than longer Ikara magazines.
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Most likely, but installation of additional blast doors (if I understood correctly, there were already blast doors between ready-use magazine and checkout area) and fire-control equipment would hardly be a major problem.
 
Pirate Pete said:
Attached is a screen grab from an article in Warship 2015…
Might help in deciding whether Seadart could be fitted to a County…
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Thank you!

Well, the pictures confirm that the only way to fit Sea Dart on County - is to develope the horizontal storage system, that would fit into former Seaslug magazine (and modify Sea Dart launcher for horizontal reload)
 
Post 7 in full.
zen said:
Well we start with the doomed Seaslug Mk III that drifted off into NIGS and so we can certainly see the basis of a SARH upgrade on the missile by using a polyrod interferometer seeker. Which externally might impact the Type 901 system most to give it SARH guidance.
Possibly one could lift the Sea Dart seeker onto such a development of Seaslug and replace the Type 901 with Type 909

It's not impossible within the dimensional constraints of the magazine system to develop an alternative new missile, and again this would effect externally the TIR system.
Such a missile might even be a linear two stage type. After all the system handles a 19ft long missile.

We can see Blue Slug offered an Anti-ship Missile option and future developments could again fit.

And it's not impossible to develop a ballistic missile option. Much like the abortive Taurus development of Terrier.

So you could extract quite an improvement.

A change in the launcher is also possible as is modification of the magazine system. Shorter missiles such a variant of Sea Dart built to be stored on it's side for example.
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As we're starting from first principles why not design the Seaslug Mk III missile to fit the County class magazine & launcher rather than modify the County class magazine & launcher to fit the OTL Sea Dart missile? We'd effectively get Seaslug Mk III/ER as an analogue to Standard ER and Seaslug Mk III/MR as an analogue to Standard MR. The latter would be built instead of Sea Dart.

CVA.01, Type 42 and Type 82 wouldn't be exactly the same as IOTL because they'd have a different launcher and magazine that was designed around the Seaslug III/MR missile rather than the launcher and magazine that was designed around the Sea Dart missile IOTL.
 
NOMISYRRUC said:
As we're starting from first principles why not design the Seaslug Mk III missile to fit the County class magazine & launcher rather than modify the County class magazine & launcher to fit the OTL Sea Dart missile? We'd effectively get Seaslug Mk III/ER as an analogue to Standard ER and Seaslug Mk III/MR as an analogue to Standard MR. The latter would be built instead of Sea Dart.
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So this is my point.
That we can deliver superior performance to MkII with a MkIII and my second point is this potentially much improved Seaslug-like missile could allow a common system for Army, Navy and Airforce.
Essentially because such developments of a Seaslug sized missile, be smaller and lighter than Thunderbird or Bloodhound.

There is a flipside option in all this, which is having the original Seaslug achieve it's performance in the smaller dimensions expected in the early 50.
I did a thread on this Smaller Seaslug.

This would more closely align with Sea Dart.....
 
zen said:
So this is my point.

That we can deliver superior performance to Mk II with a Mk III and my second point is this potentially much improved Seaslug-like missile could allow a common system for Army, Navy and Airforce.

Essentially because such developments of a Seaslug sized missile, be smaller and lighter than Thunderbird or Bloodhound.

There is a flipside option in all this, which is having the original Seaslug achieve it's performance in the smaller dimensions expected in the early 50.

I did a thread on this Smaller Seaslug.

This would more closely align with Sea Dart.....
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I'm being blond again. Is what I'm saying something different or are we in violent agreement?

What precipitated my suggestion was the discussion on whether Sea Dart was compatible with the magazine & launcher for Seaslug and if it wasn't could they be modified to accommodate Sea Dart.

Which made me think “If the mountain won't go to Mohammed, then Mohammed must come to the Mountain” or put another way “If the magazine won't accept the missile, then the missile must be designed to fit the magazine”.

In the other thread you seem to be suggesting that if the RN had done Seaslug Mk III instead of NIGS and SIGS it would have been ready in time to be fitted to the Batch 2 County class instead of Seaslug Mk II, enter service with the RAF instead of Bloodhound 2 and enter service with the British Army instead of Thunderbird 2. Which if correct is music to my ears.
 
zen said:
So this is my point.
That we can deliver superior performance to MkII with a MkIII and my second point is this potentially much improved Seaslug-like missile could allow a common system for Army, Navy and Airforce.
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Well, I noted pros and cons of such before -

Dilandu said:
So let's summarize the possibilities:

Upgrade a Seaslug GWS by developing new homing (and desirably longer range) missile:

Pros:
+ Would not require major hull or magazine alterations
+ Could use existing fire control system
+ Could implement seeker technology from Sea Dart

Cons:
- Would require developing a radically new model of rather old missile
- The whole system would still be crumblesome and bulky
- Would be less capable than Sea Dart

Replace Seaslug GWS with Sea Dart GWS:

Pros:
+ Significant increase in capabilities
+ Would be based on existing missile, with no alterations required
+ Would provide standartization with newer units

Cons:
- Would require a complete replacement of Seaslug launchers and magazines
- Would require a replacement of fire control system
- Would require a development of completely new, horizontal storage magazine and modernization of launcher for horizontal loading
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Unfortunately for some reason NOMISYRRUC ignored by posts (and I can't even remember why; I asked him several times what exactly I done wrong, so I may apologize, but he blatantly refused to answer)
 
This discussion has reminded me of the AW/Project 502 study for NIGS in 1960.
Note the missile section is 2ft shorter, diameter is 2.4in narrower, overall span is 6in greater due to the wings and booster fins. Obviously the booster makes it totally different 2-stage beast, but the fore section could be a template for a Sea Slug Mk.3, just need to find a compact booster arrangement and assuming the loading system can only handle a 19.7ft missile, then a Sea Slug/Bloodhound layout seems inevitable, but perhaps with just two rather than four boosters.

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I know some find this irksome but the UK could have learnt something from the Tartar/Terrier evolution into Standard. Current Standards take advantage of sixty years of evolution to have Talos capability in a Tartar like missile.

The UK stuck with Seaslug and created a dead end system. Seadart was better and deserved more funding than it got. A box launcher for four to six Seadarts or a VLS in place of the guns and helo deck on a County.
 
uk 75 said:
I know some find this irksome but the UK could have learnt something from the Tartar/Terrier evolution into Standard. Current Standards take advantage of sixty years of evolution to have Talos capability in a Tartar like missille.

The UK stuck with Seaslug and created a dead end system. Seadart was better and deserved more funding than it got. A box launcher for four to six Seadarts or a VLS in place of the guns and helo deck on a County.
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Sea Dart mod3, vertical launched, with the INS and millimetric seeker from the meteor would have been an awesome system at minimum cost. Ha Ho what could have been….when the development team disbands the opportunity is lost.
 
uk 75 said:
I know some find this irksome but the UK could have learnt something from the Tartar/Terrier evolution into Standard. Current Standards take advantage of sixty years of evolution to have Talos capability in a Tartar like missile.

The UK stuck with Seaslug and created a dead end system. Seadart was better and deserved more funding than it got. A box launcher for four to six Seadarts or a VLS in place of the guns and helo deck on a County.
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It's the virtuous circle that Britain always seems to be on the verge of starting but then drops the ball. In the case of the seaslug sea dart I can't see the leap with the missile itself, but perhaps in the broader context of radars and control systems the linear progress can be made.

I like the Type 984 radar and think its proliferation would be a positive thing for the RN. In the sea slug it would replace 3 radars with 1, but the Type 988 in the Bristol was to replace 2 radars with 1, the Sea Dart not needing the Type 278 height finder of the sea slug and picking up 2 guidance channels instead of 1.
 
NOMISYRRUC said:
I'm being blond again. Is what I'm saying something different or are we in violent agreement?
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Yes you're being blond
Yes we agree.
Yes that's what I'm suggesting.

Hood said:
This discussion has reminded me of the AW/Project 502 study for NIGS in 1960.
Note the missile section is 2ft shorter, diameter is 2.4in narrower, overall span is 6in greater due to the wings and booster fins. Obviously the booster makes it totally different 2-stage beast, but the fore section could be a template for a Sea Slug Mk.3, just need to find a compact booster arrangement and assuming the loading system can only handle a 19.7ft missile, then a Sea Slug/Bloodhound layout seems inevitable, but perhaps with just two rather than four boosters
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I think there be two options.
1. Is essentially a NIGS cut down by 2ft or so in length back to 19ft, fitted with 4 wrap around boosters and then a simplified NIGS system replacing the older Seaslug systems on the ship. This might need some effort on the wings and tail. Possibly folding until clear of the launcher.....though had we moved onto the alternative twin arm launcher designs. Said could unfold prior to launch on the launcher.

2. Is we produce something like the originally intended Seaslug missile body design housing NIGS missile systems in a fusilage of 15ft length with a NIGS type 23" diametee booster of 4ft length. Giving us a two stage missile of 19ft in total length.

We might add a third option, which I suspect the discovery of a 9" ARH seeker suggests something like a much shorter 'dart' using a much longer booster. Maybe like Orange Nell of 10ft and a 9ft booster. This shedding the closer ranges for longer engagement ranges.
 
uk 75 said:
I know some find this irksome but the UK could have learnt something from the Tartar/Terrier evolution into Standard. Current Standards take advantage of sixty years of evolution to have Talos capability in a Tartar like missile.

The UK stuck with Seaslug and created a dead end system. Seadart was better and deserved more funding than it got. A box launcher for four to six Seadarts or a VLS in place of the guns and helo deck on a County.
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I wondered recently if SeaDart could be air launched? Think of fitting it to F-4K's as a fill in for AIM-54
 
bobtdwarf said:
I wondered recently if SeaDart could be air launched? Think of fitting it to F-4K's as a fill in for AIM-54
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The launch itself is perfectly possible. But the guidance is a problem. You see, the polyrod interferometer seeker isn't exactly the most sensitive. Since there are no reflector to focus radio "echo" from target on receiver, you need to pump a lot of energy into target so receiver would get at least something back from long distance.

Frankly, I doubt that F-4K radar could produce enough power for Sea Dart polyrod receiver to get the target at significant range. So you would either need to launch Sea Dart on autopilot (available only for Mk II version) and switch on the homing system only when missile is close to target - which would preclude use against anything but slow, non-maneuvering targets - or you would need to install mid-course command guidance on missile, and guidance control system into F-4K fire control system. Which is expensive and would require major development.
 
Dilandu said:
The launch itself is perfectly possible. But the guidance is a problem. You see, the polyrod interferometer seeker isn't exactly the most sensitive. Since there are no reflector to focus radio "echo" from target on receiver, you need to pump a lot of energy into target so receiver would get at least something back from long distance.

Frankly, I doubt that F-4K radar could produce enough power for Sea Dart polyrod receiver to get the target at significant range. So you would either need to launch Sea Dart on autopilot (available only for Mk II version) and switch on the homing system only when missile is close to target - which would preclude use against anything but slow, non-maneuvering targets - or you would need to install mid-course command guidance on missile, and guidance control system into F-4K fire control system. Which is expensive and would require major development.
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I was thinking more of an AEW aircraft and/or ship based director for the guidance: Don't have room to add SeaDart on your carrier but do have room for the director? NP your AC acts as your launcher arm
 
bobtdwarf said:
I was thinking more of an AEW aircraft and/or ship based director for the guidance: Don't have room to add SeaDart on your carrier but do have room for the director? NP your AC acts as your launcher arm
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Hm. So basically you are suggesting to use F-4 only as flying launcher, relying on shipborne radar for target illumination? I'm not exactly sure what you would get from it; you would still be able to attack targets only within ship's radar horizon, and not even get a significant addition to range (since it would still be limited by shipborne illuminator max range).
 
Hmmm....Blue Slug....Anti-ship Missile.
One might imagine an air launched version.....
 
Dilandu said:
Hm. So basically you are suggesting to use F-4 only as flying launcher, relying on shipborne radar for target illumination? I'm not exactly sure what you would get from it; you would still be able to attack targets only within ship's radar horizon, and not even get a significant addition to range (since it would still be limited by shipborne illuminator max range).
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preferably an AEW guided one to get a bit of distance from the carrier
 
bobtdwarf said:
preferably an AEW guided one to get a bit of distance from the carrier
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Hm. First of all, it would require RN carriers to carry AEW aircraft, of which they didn't have much. Only the Gannet AEW with its venerable AN/APS-20 search radar.

Secondly, it would require AEW aircraft to carry a G/H-band narrow beam illumination radar of megawatt range peak power - that would need to be developed. The Sea Dart can't work with C-band radars, used by AEW aircraft for long-range detection (and such radars could not produce illumination beam anyway), so the AEW must be equipped with additional system.

Again, you need a lot of power to make polyrod seeker work at long distances. Those things aren't exactly the best antennas around. They were used on such missiles as Talos and Sea Dart only because the specific of those missile design (the use of integral ramjet with short inner body) precluded the efficient implementation of traditional dish-shaped antenna. The part of inner body that portruged out of ramjet intake was simply too small to put an antenna of reasonable size inside. The polyrod antenna, which was already viewed as obsolete by late 1940s, was the only one that could fit. The disadvantage was, that due to not having any reflector to focus the incoming radar "echo", the polyrod antenna was a power hog - it required a VERY powerful beam being bounced off target for any meaningful echo to come back (especially at long distances)
 
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Dilandu said:
Hm. First of all, it would require RN carriers to carry AEW aircraft, of which they didn't have much. Only the Gannet AEW with its venerable AN/APS-20 search radar.

Secondly, it would require AEW aircraft to carry a G/H-band narrow beam illumination radar of megawatt range peak power - that would need to be developed. The Sea Dart can't work with C-band radars, used by AEW aircraft for long-range detection (and such radars could not produce illumination beam anyway), so the AEW must be equipped with additional system.
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well that kills that.
 

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