UK and European alternatives to Typhon and AEGIS

[uk 75]

Zen brought the subject of the evolution of UK naval air defence systems up in another topic. I hope he will not mind me picking up his ball and adding France and other European countries into the mix.

Typhon was intended to replace Talos, Terrier and Tartar with a new radar andamily of missiles in the mid 60s. As Zen points out the only parallel European system was the RN NIGS system, which would have entered service at much the same time.

The US were forced to give up Typhon as too big and complicated, as well as costly and probably not the answer to the problem.

The three T class missiles remained in service but Terrier and Tartar were improved as the Standard missile. Talos left service at the end of the 70s as long range Standard variants became availsble.

US effort went into a powerful radar and control system called AEGIS which first entered service in the 80s on the CG 47 Ticonderoga class.

The RN meanwhile developed its own Tartar size missile (though more like Talos with its ramjet booster) as the CF299 Seadart.

No European navy adopted Talos though Netherlands and Italy adopted Terrier for their cruisers. France developed a missile.similar to Terrier. Masurca equipped three units with modifications well after the Cold War ended.

It took until the 21st Century for France, Italy and UK to develop and deploy a system similar in capability to AEGIS.

Could these three countries have developed something sooner? and what warships would have carried it?

 

[CV12Hornet]

On a technical level, I do think the Brits could have developed something with AEGIS levels of capability sooner. On the one hand, you have the Type 988 they developed with the Dutch, which had amongst its many arrays two phased arrays. It's entirely possible that with more investment a more recognizable phased array system could have been developed off of it, and cursory research suggests that the APAR system that equips the DZP, Sachsen, and Iver Huitfeldt frigates owes much to development work put into the Broomstick.

On the other hand, you have the MESAR tech demonstrator; that was undergoing trials from 1989 to 1995 and it's entirely possible had the urgency been there the Royal Navy could've beaten everyone to an AESA naval radar and put it to sea in the mid to late 1990s.

Of course, both options demonstrate the main problem with either direction: money. Broomstick went away because it was big, expensive, and the Royal Navy was desperate to cut the costs of its AAW vessels. Broomstick, let alone developing a more capable successor, is completely at odds with every pressure that led to the Type 42s. Maybe as a replacement for the Batch 3s, all of which were commissioned into an AEGIS world and which all cost more than the Batch 1 and 2 ships. MESAR 1, meanwhile, isn't going to be put to sea as I articulated because there was no real urgency to get new AAW ships into the water, not with the peace dividend on, the Type 42s still well away from retirement, and the Trident subs eating the budget alive.

The French and Italians labored under similar constraints in that era - budget was the primary reason they simply hauled their Mark 13 launchers and associated radar infrastructure off older ships and put them in new, modestly-sized hulls. The Italians, IMO, didn't have the expertise, anyway, and the French just didn't seem to hold AAW modernization as a priority, given the plan the whole time was to procure the Georges Leygues class to replace their old destroyers.

 

[Hood]

Radar
The cancellation of NIGS probably set back British radar development back a decade, not necessarily because of NIGS itself per se, but it did stop a lot of research work, or at least robbed the impetus for it. 'Broomstick' was a compromise, technical collaboration to save R&D money as applied to electronics. But it wasn't cheap and ultimately wasn't deemed important enough to keep when further cost cutting became evident. Marconi and Plessey managed to channel their planar array technology into ground-based radars (Martello etc.) but no naval spin-offs of this technology materialised.
NSR.7963 for Type 966 to replace Type 965 was trimmed then cancelled in 1976.
NSR.7938 for the new long-range Type 1015 included a lot of foreign competition (Broomstick, SPS-52 and UK designs from EMI, Plessey and Marconi, later modernised Type 965, SPS-40B, LW-08 and Selenia SPS-68) but cancelled in late 1971. These led to the interim fit with LW-08 using the AZV aerial from Type 1030. LW-08 was only chosen to make up a foreign element in an industrial workshare agreement rather than any performance or cost reason. Type 1030/1031 was itself cancelled in 1979.
So all this cut away the work necessary and all the planning needed.

Against this, active phased array radar work began in 1977 and resulted in the first array using 2.5W peak power with 1,500 modules per face in 1984. This led to the MESAR 1 (2,000 elements per face) and MESAR 2 demonstrators and then ARTIST during the later 1980s/mid-90s as well as the rotating tri-face TRISAR concept. Had NFR90 gone ahead it is likely that MESAR would have gone to sea in that form.

Fire-Control
The RN led the way with ADAWS and then CAAIS for frigates, surpassing the USN in this field but then the development into CACS was cautious and not successful while the USN jumped ahead with Aegis and NTU. The ASWE had been instrumental in the early successes but gradually the gulf between them and industry grew, especially as government favoured industry (CACS failure forcing the MoD to intervene) - the same problem affected radar development too. Plus the RN lacked any in-house software development team and gradually lost their ability to make intelligent choices as the customer or retain any IP which they could build on. Germany, France and the Netherlands did better in this regard.
I'm not sure that industry could leap from ADAWS/CAAIS to the computer power necessary for Aegis during the 1980s to be honest.

Missile
RN SAM procurement is a muddle even today (at least to me!) with conflicting overlaps and multiple choices but usually with the wrong launchers or lack of any commonality. Sea Dart was cutting edge and a good weapon, but it wasn't really upgradable to the same extent as the Standard family due to its ramjet propulsion and the layout that demanded which prevented a traditional radome. A VLS Sea Dart 2 would have been useful - but a bespoke VLS would have done little to alleviate layouts aboard ships and would have dated at the same rate as the missile. A new missile was probably a good move in order to make full use of the new Aegis-esque system. Going with Aster was not a bad move. Going with Standard might have been even better but the desire to keep MBDA alive would make this politically and industrially impossible (the same rationale makes any wholesale purchase of Aegis by Thatcher impossible too). There is perhaps a wider AU here where an Anglicised series of Standards from the 1960s onwards evolves into a linear, but separate, family. But its problematic. There are no UK drawing board designs in the 80s or 90s that can match Aster as we know it. Perhaps it might have been possible to create a similar land/sea Aster/SAMP family but it would be expensive. Plus it would need a UK spec VLS system.

Ship
Needs a new ship for sure, no point tarting up Type 42. Was NFR90 the ideal platform? Probably not but even the smaller-scope Horizon programme ended up creating three different ships for what was essentially the same role.

Collaboration?
Could the UK in the 1980s fun MESAR, UKAEGIS, SAM and the ship alone? No. So that leads to collaboration.
There is no doubt that Marconi, Plessey and Signaal are leading the way in Europe, France have little to contribute to this field - so perhaps giving them the SAM (like the historical Aster) is a way to cut costs.
I suppose one wild card would be to integrate MESAR 1 with Aegis' Mk 99 Fire Control System, Weapon Control System and Command and Decision Suite, or perhaps replacing Mk 99 with something CAAIS/CACS derived.

Time
How long would it all take? Aegis from start to initial deployment took 19 years (1964-1983). But then the USN were pushing state-of-the-art. As we've seen the UK began active phased array radar work in 1977 and MESAR 1 began trials in 1989 (12 years) and SAMPSON didn't appear on a ship for another 20 years. Going for a MESAR 1 set-up, that could have been operational maybe around 1998 (trials ended in 1994). MESAR 2/SAMPSON would be an upgrade for the 2010s (historical development was 1995-2009).
So we might end up with a Type 45 a decade earlier, but still a decade later than Aegis. The missile options are up for grabs. Whether France/Netherlands/Italy/Germany would contribute or not I don't know. It would probably mean extra cost and delay and haggling.

 

[zen]

Typhon may have been cancelled but fed a lot into the development of both upgrades to the 3T, Standard and the next generation system Aegis.

The UK NIGS started life as a Seaslug mkIII tied to a development of that technology and maybe a rotating PESA....
But the potential of relevent technologies drew them into Typhon-esque levels of capability.

It seems by the end to be heading towards something more like a 4 plate PESA system, each handed by it's own computer and then combined together in a fifth computer For overall picture and handling engagements.

This and ADAWS as originally conceived would hand off interception via Command Guidance datalink and a fairly simple TIR for SARH terminal homing.

Ironically this would have been more achievable and more relevant to later developments.
But cheap it would not have been. Though relevant to land based SAM Systems and potentially limited ABM.

The chief stumbling blocks would be signal delay technology, commuting power, memory and electrical power required.
However the US did reach for something similar with SCANFAR in C- band. So this was technically possible.
The computers advanced such that by the time of the late 60's, what seemed only a huge land based system would achieve it was no longer the case.
The nuclear power could have been met by the common naval ships reactor concepts the RN toyed with.

As JC Fuller has found, the ASWRE did build a research C-band array of modest dimensions around....if memory serves 1968.

The actual missile was so subject to uncertainty and debate it seems to be either a 21" diameter ramjet (RP.21 by Bristol's research) or a 9"-10" diameter dart lofted by a substantial booster.

In either case this would replace Bloodhound and potentially provide the basis for PAAMS long before PAAMS was conceived.

This actually has little to do with SIGS. Which ironically is more a local area defence system that thanks to the use of ramjet can extend out further.
The failure to fund ASWRE C-band 3D radar and opt for the Dutch Broomstick was entirely political and foisted increased demands on the TIR sets. Hampering the system by tying it to them tightly and making a major change for Sea Dart mkII a choice between compromise to death or scrap existing Sea Dart armed ships. As they wouldn't be compatible with such a different development of Sea Dart as a System.

Has ASWRE C-band 3D radar been funded it's possible more Sea Dart Systems would be built for RN and export.

Strictly Sea Dart was limited by ramjet and minimum range due to the booster.
SAM.72 and GAST.1210 would have been a better fit to the ASWRE System, as surely as VLS on the sefl defence SAM that realised Orange Nell capability (Sea Wolf) from Day1 would have obviated the need for SIGS. Leaving longer ranges to something else.

 

[Scott Kenny]

I don't think that you could get a system as capable as Aegis in the 1950s. At least not in anything smaller than a battleship!

France could have arguably used a half dozen or so Typhon/Aegis type carrier escorts in the 1980s, 2-3 per carrier. Hard to have carriers without escorts, and Aegis/equivalent is bragging rights for national prestige.

As long as Italy was happy to only contest the Med, I don't see them being worried about the same level of air/SLCM threat as the ships in the North Atlantic, so they're less likely to want/need Aegis/equivalent ships.

 

[zen]

I don't think that you could get a system as capable as Aegis in the 1950s. At least not in anything smaller than a battleship!

No one is saying the 1950's, save that conceptually Typhon and NIGS begin in that era and the technology is achieved in the 1960's, but would likely become operational by the 1970's.

The NIGS ships are more nuclear cruisers in the most likely form. Since powering the PESA arrays and the computers would drive a nuclear power solution.
Though they could be built to Destroyer standards.
That would not be problem for land based variants.

 

[Zoo Tycoon]

Radar

Missile
RN SAM procurement is a muddle even today (at least to me!) with conflicting overlaps and multiple choices but usually with the wrong launchers or lack of any commonality. Sea Dart was cutting edge and a good weapon, but it wasn't really upgradable to the same extent as the Standard family due to its ramjet propulsion and the layout that demanded which prevented a traditional radome. A VLS Sea Dart 2 would have been useful - but a bespoke VLS would have done little to alleviate layouts aboard ships and would have dated at the same rate as the missile. A new missile was probably a good move in order to make full use of the new Aegis-esque system. Going with Aster was not a bad move. Going with Standard might have been even better but the desire to keep MBDA alive would make this politically and industrially impossible (the same rationale makes any wholesale purchase of Aegis by Thatcher impossible too). There is perhaps a wider AU here where an Anglicised series of Standards from the 1960s onwards evolves into a linear, but separate, family. But its problematic. There are no UK drawing board designs in the 80s or 90s that can match Aster as we know it.

The game changer for Sea Dart would have been the inclusion of an autonomous microwave terminal homing radar and no more SARH . The MOD2 Sea Dart (ADAWS) successfully introduced an inertial guidance with SARH only required at terminal phase. The microwave terminal radar used in the meteor/AMRAAM indicates these are in package sizes that might install in the Sea Darts aero spike.

Sea Dart VLS was well thought through/understood so I reckon was a low risk development. Higher density fuel (Shelldyne) was also studied, tested to some degree, may have been test flown. As were some modifications to increase the missile speed, although not a big step. The minimum range problem remains, although with TVC on the booster I wonder if there was some capability for interception in the boost phase… don’t know.

All these changes would usefully increase range availability and kinetic capability… Same as Standard maybe, but probably not in terms of ABM capability.

 

[uk 75]

The difficulty for both the US and other Western nations was in finding suitable platforms for area air defence weapons both existing and planned.

The USN looked at a range of alternatives for AEGIS ranging from the high end nuclear strike cruiser to a single launcher equipped destroyer. It was a happy accident that the Spruance destroyer had enough growth potential to evolve into the Ticpnderoga class cruiser.

France seems to have had the hardest time.
Its Masurca (Terrier/Seaslug) system only found its way on to two purpose built destroyers (the RN managed 8 County for Seaslug). A third system (originally intended for the Jean D'Arc helicopter ship) was eventually placed on the ageing Colbert cruiser. The Dutch and Italians had managed this with Terrier a whole decade earlier.

The Talos missile achieved fame for its long range in shooting down N Vietnamese Migs. This disguised the reality that Soviet bombers would release stand off missiles before entering Talos range.

The big Terrier, Seaslug and Masurca missiles were also less useful as the 70s wore on.

Low level threats whether from missiles or aircraft needed more agile missiles. Tartar and its British equivalent, Seadart, were better placed to meet this. Other threads have discussed the merits of Standard (evolved Tartar/Terrier) and Seadart.

By the mid 80s as the US rolled out AEGIS on its CGs the other Western nations had nothing to match it.

The RN after 1966 contented itself with providing the ASW group for NATO in the N Atlantic. The USN had a mixture of surface ships in this role with new Spruance ASW destroyers replacing wartime built ships. The Knox class frigates were the USN equivalent of the RN and Dutch Leanders while the new OH Perry air defence frigates with their single Standard launcher matched the RN T42.

AEGIS ships were mainly tasked with screening the aircraft carriers. In contrast the largest new RN vessels were ASW helicopter cruisers armed for self defence with Seadart. The Italians had long had similar ships.

Pre 1966 a Royal Navy carrier group had been planned to be screened by a mixture of Seaslug and Seadart equipped ships. Reflecting early 60s US prectice the carrier itself would also be equipped with Seadart.

The RN simply did not have the resources to develop something like AEGIS. Its main air defence ship had shrunk over time from the proposed Seaslug cruiser to a frigate enlarged to carry Seadart. Only the cumbersome size and weight of the Seadart system (compare a T42 with a Perry to see what I mean) ensured that destroyers rather than frigates carried it.

On the other hand the RN did develop the Seawolf system. This too was cumbersome requiring the big T22 to mount double ended launchers, but it gave the RN a unique capability for its exposed role in the N Atlantic. Nothing in the USN inventory matched Seawolf.

 

[zen]

The chief potential for NIGS is a unified solution for long range area defence.
But it doesn't solve the local area and close in defence needs.

The US approach handed long range to Aegis and short range remained under the evolution of a lashup into eventually increasingly range and capability enhanced Sea Sparrow developments and an entirely new....if a little familiar to SHIELD system called SeaRAM.

The chief real issue was increasingly the concern of being overwhelmed by multiple Anti-ship Missiles from multiple directions. Which could be launched from outside the SAM bubble by aircraft or close inside the bubble by submarine.

This is where Sea Dart hit it's own problem in the Type 43 effort, not strictly the systems so much as magazine capacity. Though sticking with launchers and loaders and a limited number of TIR couldn't have helped.

VLS doesn't solve that directly unless the weight and cost savings be invested in larger magazines.

And it's my contention that SAM.72 and GAST.1210 are attempts not just meet the French tripartite requirements but to merge close in defence (Sea Wolf) with further out (SIGS- Sea Dart mk1). Which ought to solve a lot.

The real history answer was Horizon PAAMS in Aster-15 and at the time Sea RAM giving the capability to counter mass attacks.

But here's the heart of my concern, nothing beats trying to do it for learning.
The failure to fund PESA and the computer systems meant no experience which might feed into other radars and computer systems. Which would extend into aircraft and fixed site systems etc...

As it was ADAWS retained elements of it's origin, which likely kept it competitive for far longer.

The burden of the 909 at least cane with a degree of redundancy and capability, though that aspect of them is yet to be revealed publicly.

Theory is fine, but until you try to do it for real, you are doomed to make painful mistakes and/or advance slowly to operational goals.
As it was it took decades to go from a slowly funded PESA C-band research radar to the AESA effort of MESAR and Sampson.

 

[Scott Kenny]

No one is saying the 1950's, save that conceptually Typhon and NIGS begin in that era and the technology is achieved in the 1960's, but would likely become operational by the 1970's.

The NIGS ships are more nuclear cruisers in the most likely form. Since powering the PESA arrays and the computers would drive a nuclear power solution.
Though they could be built to Destroyer standards.
That would not be problem for land based variants.

Typhon still wasn't done in the 1960s, the entire setup was too big for even something like the Long Beach.

It took the 1970s solid state breakthroughs to get Aegis small enough to fit into a 9000ton ship in the 1980s.

 

[A Tentative Fleet Plan]

Typhon was certainly capable of fitting on a Long Beach hull, most Typhon DLGN designs displaced circa 10,000 tons, some below that figure (and in those cases, the main drivers in size were increased endurance, NTDS, and the SQS-26 sonar). Aegis was barely crammed aboard a Spruance hull as it is, I doubt the ship impact was all that much smaller (perhaps larger, given the need for separate illuminators and four separate S-Band phased arrays). The effect of the SPG-59 on ship endurance seems to be over-egged, it seems Aegis had the same effect, there is a brief description of the effect of the SPY-1s on the endurance of the Ticonderoga-class in Navies in the Nuclear Age. At time of cancellation the largest Typhon design under consideration was 12,000 tons, hardly an impossibility for a Fast Task Force Escort. I expect a clean-sheet Aegis ship would have been similarly sized.

I don't think NIGS with "Type 985" (which I will be using as a short-hand for ASWE's phased array radars) is really an Aegis equivalent, you need missile autopilots and data-links between the missile and ship to ensure that, with the S-Band PESAs providing reasonably accurate target updates, that are then communicated to the missiles in flight (which know where they are due to their onboard INS), with targets being illuminated by time-shared by illuminators in the terminal stage.

NIGS seems to be similar to later developments of the 3-T series and early Standards, with Semi-Active terminal homing rather than Beam-riding, and potentially progressive guidance like Sea Dart, giving it greatly increased range, but still vulnerable to saturation with the missile autopilots and data-links. In terms of fire control in terms ADAWS was designed to do both track-keeping and weapons control, the US approach was to have these separate, with Typhon and Aegis having separate fire control computers with NTDS for track-keeping. ASWE's phased arrays seem to be a 3D equivalent to the SPS-32/33 combination, performing the role of both in a single array rather than two.

 

[Scott Kenny]

Typhon was certainly capable of fitting on a Long Beach hull, most Typhon DLGN designs displaced circa 10,000 tons, some below that figure (and in those cases, the main drivers in size were increased endurance, NTDS, and the SQS-26 sonar). Aegis was barely crammed aboard a Spruance hull as it is, I doubt the ship impact was all that much smaller (perhaps larger, given the need for separate illuminators and four separate S-Band phased arrays). The effect of the SPG-59 on ship endurance seems to be over-egged, it seems Aegis had the same effect, there is a brief description of the effect of the SPY-1s on the endurance of the Ticonderoga-class in Navies in the Nuclear Age. At time of cancellation the largest Typhon design under consideration was 12,000 tons, hardly an impossibility for a Fast Task Force Escort. I expect a clean-sheet Aegis ship would have been similarly sized.

Wasn't Typhon like SCANFAR, and very top heavy, though?

I don't think NIGS with "Type 985" (which I will be using as a short-hand for ASWE's phased array radars) is really an Aegis equivalent, you need missile autopilots and data-links between the missile and ship to ensure that, with the S-Band PESAs providing reasonably accurate target updates, that are then communicated to the missiles in flight (which know where they are due to their onboard INS), with targets being illuminated by time-shared by illuminators in the terminal stage.

NIGS seems to be similar to later developments of the 3-T series and early Standards, with Semi-Active terminal homing rather than Beam-riding, and potentially progressive guidance like Sea Dart, giving it greatly increased range, but still vulnerable to saturation with the missile autopilots and data-links. In terms of fire control in terms ADAWS was designed to do both track-keeping and weapons control, the US approach was to have these separate, with Typhon and Aegis having separate fire control computers with NTDS for track-keeping. ASWE's phased arrays seem to be a 3D equivalent to the SPS-32/33 combination, performing the role of both in a single array rather than two.

I will defer to your expertise there, I'm particularly unread on UK ship radars.

 

[datafuser]

Can anyone please explain how it works?

 

[red admiral]

But here's the heart of my concern, nothing beats trying to do it for learning.
The failure to fund PESA and the computer systems meant no experience which might feed into other radars and computer systems. Which would extend into aircraft and fixed site systems etc...

This is at the heart of a lot of UK issues. Funding the TRL4-9 side requires huge amounts of money compared to lower TRL. And then you might be pushing technology so much that even getting to TRL9 you may still end up with a dud. You will learn things along the way to feed into subsequent efforts, but you've already spent the "radars R&D" money, and robbed R&D fubding from other areas to do so. Choosing to focus on much fewer areas feels like it would be better, and then making more evolutionary changes rather than "leap ahead"

 

[zen]

This is at the heart of a lot of UK issues. Funding the TRL4-9 side requires huge amounts of money compared to lower TRL. And then you might be pushing technology so much that even getting to TRL9 you may still end up with a dud. You will learn things along the way to feed into subsequent efforts, but you've already spent the "radars R&D" money, and robbed R&D fubding from other areas to do so. Choosing to focus on much fewer areas feels like it would be better, and then making more evolutionary changes rather than "leap ahead"

Certainly the UK tended to try to leap ahead based on theory and often the expense and difficulties of making it reality collapsed such efforts or they took so long as to be superseded by other developments.

Nothing quite whispers what might be than ADAWS itself. Rooted in the realisation that staring array radars would produce enormous amounts of data that needed handling.

I might even be so bold as to suggest this is the thing most worth trying to do at that time. As it builds the foundations of fully computerised AAW Systems. Fundamental to to everything from ABM to Local Area defence and in variations out to handling ASW.

I might suggest ASWRE was right and the costs of funding them would be offset by their potential if successful.
Their C-band 3D radar would likely have been fitted to Type 82, Type 42, Type 22, and the Invincibles....maybe even Type 21.

The system behind those would potentially have been upgradable to 4 face PESA or AESA as computer capability increased. Making the case for Type 43 or 44 much stronger.
Maybe not Aegis, but certainly better than what was.

Sea Dart mkII or SAM.72 and GAST.1210 would have been more easily achieved under such conditions.
The French may have been satisfied even if the Dutch would not be.
I might contend winning the French over here could lead to knock-on benefits elsewhere.

 

[zen]

I don't think NIGS with "Type 985" (which I will be using as a short-hand for ASWE's phased array radars) is really an Aegis equivalent, you need missile autopilots and data-links between the missile and ship to ensure that,

The NIGS effort is post Blue Envoy and that likely retains ambitions on ARH seekers at some future stage.
The Bloodhound mkII used autopilot and the UK worked on datalinks quote a bit.
Hence Ferranti being funded on a complete auto-interception system for the Lightning. Which was built at least to prototype state.

The potential for TVM as a development is also present.

The UK equivalent to Typhon itself seems very brief and is summed up as study of a ship with a system mysteriously named Trackwell.

 

[A Tentative Fleet Plan]

The NIGS effort is post Blue Envoy and that likely retains ambitions on ARH seekers at some future stage.
The Bloodhound mkII used autopilot and the UK worked on datalinks quote a bit.
Hence Ferranti being funded on a complete auto-interception system for the Lightning. Which was built at least to prototype state.

The potential for TVM as a development is also present.

The UK equivalent to Typhon itself seems very brief and is summed up as study of a ship with a system mysteriously named Trackwell.

If the fire control system allowed it, NIGS could certainly be fired at higher rates than Typhon-LR in the Mk 10 GMLS, from the images posted on this forum we can see that the missiles were full assembled, no need to attach fins before launch.

 

[uk 75]

Talos is the only missile deployed that was similar to NIGS in size. The three Albany class with Talos at either end were hugely expensive and way beyond the reach of the RN.

On the other hand the County class DLGs were probably big enough to take a single NIGS launcher aft and the required radars. Weight issues might have forced the removal of 4.5 guns.

 

[A Tentative Fleet Plan]

Wasn't Typhon like SCANFAR, and very top heavy, though?

SPG-59 would have pretty much replaced all the radars on a DLG, bar the SPS-10 for surface search, and a SPS-43 or -49 for long-range air search.

There were separate 3,400 and 10,000-element designs for DLGs and Cruisers respectively.

 

[JFC Fuller]

I don't think NIGS with "Type 985" (which I will be using as a short-hand for ASWE's phased array radars) is really an Aegis equivalent, you need missile autopilots and data-links between the missile and ship to ensure that, with the S-Band PESAs providing reasonably accurate target updates, that are then communicated to the missiles in flight (which know where they are due to their onboard INS), with targets being illuminated by time-shared by illuminators in the terminal stage.

NIGS seems to be similar to later developments of the 3-T series and early Standards, with Semi-Active terminal homing rather than Beam-riding, and potentially progressive guidance like Sea Dart, giving it greatly increased range, but still vulnerable to saturation with the missile autopilots and data-links. In terms of fire control in terms ADAWS was designed to do both track-keeping and weapons control, the US approach was to have these separate, with Typhon and Aegis having separate fire control computers with NTDS for track-keeping. ASWE's phased arrays seem to be a 3D equivalent to the SPS-32/33 combination, performing the role of both in a single array rather than two.

NIGS was only semi-active homing in the terminal phase. For most of the flight, the mid-course, it would have used command guidance. The shipboard radar (NSR) would have tracked the missile and the target, the commands required to keep the missile aligned with the target would have been generated onboard the ship and then sent to the missile.

The final NIGS report doesn't go into much detail about rate of fire or simultaneous engagements but it does imply that it was limited by the rate of fire of the launchers, a figure of ten missiles a minute is given for a double-ended ship (e.g. two twin launchers). However, the reload and firing cycle times given suggest 12 should have been possible, unfortunately the drawing showing the cycle doesn't appear to have survived so I can't explain that discrepancy. The report gives an RoF of 6 missiles per minute for a single US Mk10 GMLS, I would say they were probably about equal.

The proposed NIGS solution, in terms of very high-level system architecture, has some similarities to the later US Aegis system, especially AN/SPY-1A as ultimately deployed on the Ticonderogas and designed into the strike cruiser and CGN-42. It would have had four fixed arrays fed by two transmitters, one either end of the ship, responsible for volume search, target and missile tracking, mid-course guidance for the missiles and four relatively low powered illuminators only used for terminal homing. Aegis used a different radar technology and almost certainly more powerful transmitters and computers though - being a later solution.

@uk 75 , NIGS was to be roughly Terrier size, rather than Talos size, and the entire system was sized for the County class hull, albeit without any guns. Personally I think the County hull would have been too small but it probably could have gone on a 8-10,000 ton ship.

 

[A Tentative Fleet Plan]

The Midcourse Guidance and time-shared Illuminators are the important bits, judging by your description seems to be a capable system dealing with significant saturation along the lines Typhon or Aegis.

 

[Purpletrouble]

Been considering alternate RN's in the postwar era and of course the LR SAM system evolution is fundamental to that.

A SAM system is essentially 4 components.

(1) The missile.
(2) The search/indication radars.
(3) The directors for guidance, be it just terminal or full time.
(4) The combat management system.

Aegis of course is actually just (4), although is typically referred to in a manner that covers all of them. Its strength was doing (4) extremely well, drawing in data and procesing that plus having control of weapons integrated. That was new for the US (NTDU didn't do that as comprehensively iirc) but arguably is kind of what ADAWS had done on a simpler, less capable level, from its outset for the RN.

For the RN to have something like Aegis in the 80s, on say a new DLG (type 43 style thing), it'd need:

(1) An improved Sea Dart (Mk2) missile, probably still twin launcher based as a boosted ramjet, perhaps TVC reducing min engagement range. Onboard autopilot and datalink to allow timesharing, the critical technology that massively boosts your ability to conduct simultaneous engagements. Most of that was done albeit later in the 80s as part of ADIMP. Other improvements (fuel type for more range etc.) could make a SD2 akin to a SM2 I feel.

(2) Out of the 70s NSRs for better S.Dart radars, 1022 replaced ancient 965. 996 came along not long afterwards providing a 3D capability vs 992 which had forced inefficient use of the 909s for height finding (aiui, happy to be corrected!). Could this have been done sooner or better? Probably, there were other attempts to replace 965/992 earlier although I dont know why they failed (technical or just money?).

Lots of talk about ASWE C band but it literally went nowhere and was probably aiui more like SCANFAR and not DLG suited plus ahead of being able to be realised (hence why it wasnt). 988 nearly existed (indeed did across the channel) - presumably if 988 had been continued with, and say fitted to the Invincibles also, the RN would be in a better place than with 965/992 (that the Dutch did produce something that aiui was decent shows it was well within the UK's capability). But a decent radar fit, even if not SPY-1, was doable. (noting the Ticos had SPS-49 also)

(3) 909 was heavy, but worked quite well. It seems very overpowered for Sea Dart ranges, I assume it came out of NIGS work, but the power was useful for heavy ECM environments. It seems good enough and aiui was upgraded for time sharing etc. It'd be nice if something smaller/lighter and more suited to Sea Dart could have been developed, offering opportunity to fit more per ship.

(4) The CMS. ADAWS was the benchmark here until Aegis arrived, but the UK seems to have effectively stopped developing it in the 70s and went to less capable CAAIS and CACS. CACS was a failure as it couldnt cope with the amount of data. Hence the real life Type 43 with Sea Dart 2 presumably would have hit this rather show stopping issue? Perhaps if the RN had kept ADAWS development up in support of fleet AAW requirement for a DLG it would have a CMS closer to what Aegis was to support Sea Dart 2.


Thus it seems safe to say the UK could have had an Aegis-like* system with relatively few butterflies required. I wonder if a good SD2, (better) 988 (backed by 1022?), improved 909s and a developed ADAWS MkX with 70/80s IT could have been at least on the same field as Aegis.

* emphasis on like. The software and hardware to make Aegis was cutting edge and the US was well ahead in terms of sw/hw by the 70s and even if the UK had prioritised ADAWS style development I dont think we'd have been able to match Aegis for capacity/performance.