Could the UK have done a better job of maintaining carrier based air power?

[uk 75]

The paper designs of BAC and HS in 1950s and 60s were in many cases wonderful to look at, especially in model form.
The trouble is that the planes they actually built took a long time to get into service and delivered below their promised performance. Lightning, Buccaneer, Harrier and Jaguar all fall into this category. It is no accident that by 1990 the Hawk is the only all British combat aircraft left in production whereas Dassault is still turning out delta wing jets.
Blaming politicians for this state of affairs ignores the people who designed and built horrors like the Swift, Buccaneer S1 or Nimrod AEW.

 

[zen]

In what ways were the Buccaneer S.1 and Nimrod "horrors"?

 

[uk 75]

In what ways were the Buccaneer S.1 and Nimrod "horrors"?

Buccaneer S1 was underpowered and the S2 was not in service until 1965 just in time for the carrier cancellation of 1966. The AEW.Nimrod saga is well enough known (the ASW version went on to have its own problems with the Mk4)
Harrier and Jaguar both entered service with perdormance issues. Lightning radar and missiles were obsolete when the plane entered service let alone in the 80s.

 

[uk 75]

It is possible to take paper projects and turn them into alternatives to the real world aircraft but my issue is with the timescales involved and using hindsight to give them characteristics from later periods.
The Vickers aircraft evolved into decent paper projects, AFVG and UKVG and into actual hardware,Tornado. But the early iterartions would have only been test machines like the Bristol 188 and BAC 221.

 

[zen]

1. Gyron Junior is a DH product and lacked orders for DH to invest enough in it. Not Blackburn's fault.

2. Nimrod was a ASW platform and though it has issues. It was not a failure.
The specifics of the AEWACS effort was a complex failure of systems management, government management and poor choice of airframe.
Not an inherent fault of a ASW variant of a civil transport.

No aircraft enters service perfectly and no prototype is perfect.

 

[Hood]

I don't think this POD requires much effort, all it requires is for Peter Thornycroft to get the "bright idea" to merge OR.343 and OR.346 into a single joint-service VG aircraft instead of getting the "bright idea" to merge OR.356 and AW.406 into a single joint-service VTOL aircraft (as happened in OTL).

I like that POD personally. I think BAC would have loved this too. HSA less so.

Purely on a Navy basis, designing future carriers for aircraft like Type 583 would massively ease the design and building of such. Though in cost terms accepting compromise on a fixed wing design saves time and money.

Yes, carrier design was important here - which is probably why the Admiralty beefed up CVA-01 to take F-111B-class aircraft for future growth. Being constrained by physical limits on how big they could build the carrier, this always influenced the desire for maximum lift, whether by aerodynamic means or by direct vertical thrust.

For me (and I've said this several times before), the OR.346 designs are mostly 'freakish' in some way and none of them are really 100% feasible without further developments in aerodynamics, propulsion and electronics. All were high-risk to some degree and all were expensive. Partly this was due to carrier deck performance constraints that they had to meet.

This loops back to Fleet Plan's comment. The industry was heavily divided by 1962 into two camps - BAC championed the VG wing, HSA championed thrust-vectoring. And so nearly all ORs, ASRs etc. from 1960 to 1974 were always a binary choice (even AST.362 was written around VG wings and VTOL was "desirable"!) - the RAF/RN could chose from VG or VSTOL with completely different methods of operation and technical risks with very little alternative middle-ground in terms of conventional fixed-wing designs - which is why often as not overseas types like Phantom, C-130 and Jaguar looked attractive. BAC rarely dabbled in V/STOL and HSA rarely dabbled in VG so the industry was split.

 

[zen]

I've said this elsewhere but if your designing a carrier around improved mk14 and BS6 at 151ft stroke and aircraft to AW.406 of a maximum of 50,000lb, your carrier design gets a lot easier and at lot more affordable at lower risk.
The real 1960 42,000ton study would start to have a lot more strength in debates.

 

[A Tentative Fleet Plan]

I don't think making CVA-01 smaller reduces technical risk (although it might reduce political risk). Many of the technical innovations, and hence technical risks in the design are to force the displacement below the 53,000 ton limit. With a 42,000 ton design the risk of additional technical risk is even greater. Better to build a big dumb 68,000 tonner, and limit the radars to Type 992 and Type 965, and eschew anything risky and/or expensive like Type 184 sonar, Type 988 radar, Sea Dart, Ikara, scissor lifts and QT35 steel.

 

[Scott Kenny]

I don't think making CVA-01 smaller reduces technical risk (although it might reduce political risk). Many of the technical innovations, and hence technical risks in the design are to force the displacement below the 53,000 ton limit. With a 42,000 ton design the risk of additional technical risk is even greater. Better to build a big dumb 68,000 tonner, and limit the radars to Type 992 and Type 965, and eschew anything risky and/or expensive like Type 184 sonar, Type 988 radar, Sea Dart, Ikara, scissor lifts and QT35 steel.

I'd want to keep Sea Dart, Sea Wolf is painfully short ranged so basically only gives you one shot at any given incoming.

 

[zen]

The technical risk is primarily associated with:-
1. A design to accommodate and operate 75,000lb aircraft with
2. 250ft catapults.
3. DA Arrestor engines
4. New 1,000 degree and 1,000psi steam plant.
5. Scissor lifts.
6. New ADAWS
7. Type 988 Broomstick 3D radar
8. Type 909 Desertcar TIR
9. Sea Dart System (launcher, magazine handling system etc)

 

[NOMISYRRUC]

3. Scrapping the Audacious and Maltas ought to have opened up to 3 to 6 slips of roughly the right length at the right time for this 1948 Carrier.

For what it's worth Eagle was launched in 1946, Ark Royal was launched in 1950, the Maltas weren't laid down and in my timeline Argus, ALT-Eagle & ALT-Hermes were to be laid down in 1950.

As the decision to build them was taken in 1946 it would have been possible for the Admiralty, Board of Trade and the shipyards to arrange the building schedules of merchant ships in such a way that 3 slipways of the required length were available in 1950.

Link to Post 479 about Britain's shipyards in 1940.

I counted 6 yards with at least one slipway that was long enough to build a 1952 Aircraft Carrier.

 

[NOMISYRRUC]

The technical risk is primarily associated with:-
1. A design to accommodate and operate 75,000lb aircraft with
2. 250ft catapults.
3. DA Arrestor engines
4. New 1,000 degree and 1,000psi steam plant.
5. Scissor lifts.
6. New ADAWS
7. Type 988 Broomstick 3D radar
8. Type 909 Desertcar TIR
9. Sea Dart System (launcher, magazine handling system etc.)

We know that 6 out of 9 worked. The ones we don't know about are Nos. 1, 2 and 4. However, aren't 1 and 2 scaling up existing technology? E.g. the 199ft BS.5 steam catapults worked, how much harder is it to make one that is 51ft longer? The one that I don't like the look of is No. 4 the steam plant. What were the chances of it failing? The gas turbine version proposed by me has its drawbacks but at least we know it would have worked because it did on the Invincible class.

 

[uk 75]

I still think (assuming a different political rationale for carriers rather than submarines) the Centaur class could be a reasonable platform for Sea Vixens and Buccaneers with AFVG taking over in 1972 (it is a mature design unlike the early Vickers VG drawings).
As for what takes over, I think a gas turbine powered De Gaulle variant would suit both UK and France with two ships for each country.

 

[Scott Kenny]

I still think (assuming a different political rationale for carriers rather than submarines) the Centaur class could be a reasonable platform for Sea Vixens and Buccaneers with AFVG taking over in 1972 (it is a mature design unlike the early Vickers VG drawings).
As for what takes over, I think a gas turbine powered De Gaulle variant would suit both UK and France with two ships for each country.

You still need 3 ships in service to have one available for use 24/7, assuming one crew. Two crews and short deployments (3 months instead of 6) can get you to 4 ships in service to have 3 at sea.

 

[uk 75]

Getting 3 Invincibles into service took over a decade and the RN only had the manpower and budgets to operate one in service with a second in wartime. It was rare for all three to be available.
Unlike the US Navy the RN relies on its submarines (missile and hunter killer) as its primary weapons.

 

[BlackBat242]

The technical risk is primarily associated with:-
1. A design to accommodate and operate 75,000lb aircraft with
2. 250ft catapults.
3. DA Arrestor engines
4. New 1,000 degree and 1,000psi steam plant.
5. Scissor lifts.
6. New ADAWS
7. Type 988 Broomstick 3D radar
8. Type 909 Desertcar TIR
9. Sea Dart System (launcher, magazine handling system etc)

We know that 6 out of 9 worked. The ones we don't know about are Nos. 1, 2 and 4.

No. 5 was actually built in the Invincible class... their scissors lift was the same design, just adjusted a bit in size.

And there were severe problems with it... not severe frequency of occurrence, but severe when it did happen.

They were supposed to go up and down like this:




But every so often, they would do this:



Which required a run back to port to get it fixed in a shipyard.

MAJOR LIFT FAILURES
Since introduction into service there have been several serious and near catastrophic aircraft lift failures due to uncontrolled tilting of the lift platform (FIG. 14). In each case ships have had to withdraw from operational commitments and expensive and manpower-intensive base support has been required to return the lifts to normal operation. In the majority of failures the prime cause of loss of control of the platform has been centred around the synchronizing system.

See the following document (I have the text in a Word document, and also the images referred to in the document, and will email them to anyone who wants them):

CVS AIRCRAFT LIFTS © Crown Copyright/MoD (1987).
BY LIEUTENANT-COMMANDER D. STRAWFORD, R.N. (H.M.S. Ark Royal, formerly staff of C-in-C Fleet)​

 

[zen]

So in contrast to the potential pitfalls of CVA-01.

BS.4 worked.
Darings upgrade was I think 600psi at 750 degrees.
YEAD-1 new cruiser plant was built and tested at Pamatrada for 30,000shp.
Which was 700psi at 950 degrees F.

So arguably scaled up YEAD-1 to 50,000shp as new capital ship plant is not unreasonable and much more risk adverse.
While the County Plant Y102A used two 15,000shp steam turbines and four 7,500shp gas turbines.
Scaling up for 30,000shp steam and 20,000shp gas is not unreasonable.

Existing lifts worked.
Mk14 arrestors worked.
CDS worked.
Type 984 worked
All proved in the 50's.
And consequently risk low.

Though the vacuum tube based electronics does need to move to transistors amd that's not a trivial change.

 

[Pirate Pete]

BlackBat242.
Not meaning to steal your thunder but found this version of the document in pdf format.

 

[NOMISYRRUC]

Though the vacuum tube based electronics does need to move to transistors and that's not a trivial change.

Shouldn't that be a good thing? As I understand it solid state electronics were more reliable, more powerful and less expensive than vacuum tubes.

That came from the first time I read a Norman Friedman book. According to him one of the reasons why 50-odd first generation guided missile ships were built by the USN instead of 100-odd planed was the unreliability of their vacuum tube electronics. The USN had to spend a considerable sum on a "get well" programme in which the valves were replaced with transistors & silicone chips. The USN was pleasantly surprised when the "cured" systems performed better as well as being more reliable.

 

[NOMISYRRUC]

What @BlackBat242 wrote about the scissors lifts in the Invincible class.

Fair enough and for what it's worth I knew about that because its been in other threads here.

What I though might make such failures on CVA.01 more frequent is that the former were bigger and designed to carry double the weight of the latter. On the other hand it might be a six-and-two-threes because the Invincible class had two scissors lifts and the CVA.01 class would have and one scissors lift and one conventional lift.

One thing in favour of CVA.01 is that a failure of the forward lift wouldn't make the landing lane and steam catapults unusable, but a failure of either lift on an Invincible made the runway for the Sea Harriers unusable.

 

[zen]

Shouldn't that be a good thing?

Yes....and no.

Yes obviously transistor electronics are just more reliable and easier to replace.

No in that a move to transistors means a complete redesign anyway, as you cannot use the vacuum valve power levels of the original design. So every circuit has to be redesigned and the transition from radar signal to digital signal is inherently a compromise.

Furthermore Type 984 used a mechanical vertical movement of feed horns behind the lense. So the temptation would be to upgrade to Electrically Scanned.....which has the potential to spiral away from the known proven system to something new and risky.....

All of this was done I think on Type Firelight and Scorpion for Bloodhound and Thunderbird. So it's not impossible, just more risk.

 

[NOMISYRRUC]

Yes....and no.

Yes obviously transistor electronics are just more reliable and easier to replace.

No in that a move to transistors means a complete redesign anyway, as you cannot use the vacuum valve power levels of the original design. So every circuit has to be redesigned and the transition from radar signal to digital signal is inherently a compromise.

Furthermore Type 984 used a mechanical vertical movement of feed horns behind the lense. So the temptation would be to upgrade to Electrically Scanned.....which has the potential to spiral away from the known proven system to something new and risky.....

All of this was done I think on Type Firelight and Scorpion for Bloodhound and Thunderbird. So it's not impossible, just more risk.

Was Type 984 to be fitted to CVA.01? I was under the impression that it was to have Type 988 which was fitted to the Dutch "Kojak" destroyers and I've not heard anything about that not working.

Eagle was fitted with Type 984M which had solid state electronics and I've not heard of it being any more unreliable than the vacuum tube Type 984s on Hermes & Victorious. Although Type 984M having solid state electronics may be a false memory on my part and the Type 984M might be one too.

On the other hand I have written proof that the the Type 965 radars on the Batch 1 Type 42s had sold state electronics because the book about them on the shelf to my right says the Type 965P with which they were fitted was the solid state version of Type 965.

 

[NOMISYRRUC]

So in contrast to the potential pitfalls of CVA-01.

I may be blond again because some of the equipment in that list wasn't for CVA.01.

BS.4 worked.

And as far as I know so did BS.5, but the catapults for CVA.01 were BS.6s.

Existing lifts worked.

Except one was conventional and the other was a scissors lift & as @BlackBat242 reminded me they had issues.

Mk14 arrestors worked.

Is that a different designation for the arrester gear that had trials aboard Eagle in the late 1960s, was fitted to Ark Royal 1967-70 and was intended for CVA.01?

CDS worked.

Yes, but they had moved onto ADA and ADAWS-1 with 3 & 2 Ferranti Poseidon computers respectively (which I don't know, but suspect used transistors instead of valves) for Eagle and the County class Batch 2. CVA.01 herself was to have been fitted with ADAWS-3 which used Ferranti FM1600 computers.

Type 984 worked

As already written CVA.01 had Type 988.

All proved in the 50's.

Except some of it wasn't intended for CVA.01. More modern and at February 1966 as yet unproven was.

And consequently risk low.

See about, except that most of the risks paid off.

Though the vacuum tube based electronics does need to move to transistors and that's not a trivial change.

Some of the equipment did have transistors and silicone chips.

 

[Scott Kenny]

Shouldn't that be a good thing? As I understand it solid state electronics were more reliable, more powerful and less expensive than vacuum tubes.

That came from the first time I read a Norman Friedman book. According to him one of the reasons why 50-odd first generation guided missile ships were built by the USN instead of 100-odd planed was the unreliability of their vacuum tube electronics. The USN had to spend a considerable sum on a "get well" programme in which the valves were replaced with transistors & silicone chips. The USN was pleasantly surprised when the "cured" systems performed better as well as being more reliable.

You kinda answered your own question. The improved reliability and power is good. The redesign is not cheap, though.

 

[NOMISYRRUC]

You kinda answered your own question. The improved reliability and power is good. The redesign is not cheap, though.

Except I was under the impression that the electronics on CVA.01 were new systems with solid state components from the word go rather modifications of existing designs with solid state components in the updated versions replacing the valves in the original versions.

 

[BlackBat242]

BlackBat242.
Not meaning to steal your thunder but found this version of the document in pdf format.

Thanks for finding that - I had tried to find a PDF version, but failed.

 

[zen]

In context. The context of both scenarios of a homogenous fleet of Carriers built in the 50's and a alternative CVA-01.

A lower risk carrier is one using known and debugged systems already in use.

So you are right on Type 984M to my knowledge, in terms of the back end, but the actual radar relied on valve based systems like the majority did.

The alternative to Broomstick (Type 988) is the domestic effort by ASWRE. Which was a C-band 3D radar.
This has the potential to make the 909 TIR sets rather different. Lighter and easier to place. Which is fundamentally a shift of resources, but shouldn't be prohibitive.
This would be applied for Type 82 Destroyers the Carriers and Type 42s. Potentially this would simply be applied to Type 21 and Type 22 as well. Being the standard 3D system with ADAWS.

 

[Hood]

The alternative to Broomstick (Type 988) is the domestic effort by ASWRE. Which was a C-band 3D radar.
This has the potential to make the 909 TIR sets rather different. Lighter and easier to place. Which is fundamentally a shift of resources, but shouldn't be prohibitive.
This would be applied for Type 82 Destroyers the Carriers and Type 42s. Potentially this would simply be applied to Type 21 and Type 22 as well. Being the standard 3D system with ADAWS.

All I can say is YES 1000x YES this should have happened.

I've seen references that Type 988 was only chosen because of the need to provide a Dutch workshare in return for UK workshares in another unrelated programme, does anyone have any idea what that other programme was?

 

[zen]

does anyone have any idea what that other programme was?

My understanding is Sea Dart. The Dutch committed to it only to renege when costs started to firm up. They got Standard cheaper and the US let them use their combat system.....
Which they developed after looking at ADAWS......
Which is not yo say ADAWS is inferior, anything but, rather that they got ideas of a simpler system.

RN was stuck with Broomstick because ministers couldn't face the embarrassing climbdown and were desperate to prove their 'European' credentials to get EEC entry.

 

[Pirate Pete]

Was Type 984 to be fitted to CVA.01? I was under the impression that it was to have Type 988 which was fitted to the Dutch "Kojak" destroyers and I've not heard anything about that not working.

Eagle was fitted with Type 984M which had solid state electronics and I've not heard of it being any more unreliable than the vacuum tube Type 984s on Hermes & Victorious. Although Type 984M having solid state electronics may be a false memory on my part and the Type 984M might be one too.

On the other hand I have written proof that the the Type 965 radars on the Batch 1 Type 42s had sold state electronics because the book about them on the shelf to my right says the Type 965P with which they were fitted was the solid state version of Type 965.

Cannot recall where this Artists Impression originates but I seem to recall a comment attached to it that 'this is probably how CVA-01 would have appeared' (after cancellation of the Type 988 Broomstick radar...Understandably I think it is VERY 'what-if'!

 

[zen]

To avoid numeric confusion, ASWRE C-band 3D set could be named Bookkeeper (my invention). Likely available by 1970-72. Though early set might be on Type 82....

However Type 984M might evolve into 984N swapping mechanical vertical movement for electrical scan. Lightening existing set and setting the stage for Bookkeeper.

Such a system with TIA (Target Indicating Aerial) might form an easier path for Sea Dart mkII.

 

[NOMISYRRUC]

The alternative to Broomstick (Type 988) is the domestic effort by ASWRE. Which was a C-band 3D radar.
This has the potential to make the 909 TIR sets rather different. Lighter and easier to place. Which is fundamentally a shift of resources, but shouldn't be prohibitive.
This would be applied for Type 82 Destroyers the Carriers and Type 42s. Potentially this would simply be applied to Type 21 and Type 22 as well. Being the standard 3D system with ADAWS.

Is there an unused number in the RN's radar "Type" system that can be given to this radar?

 

[Hood]

Well Peter Marland's article in Warship 2022 'Post-War Radar Development in the Royal Navy' gives a handy table and some pointers.
Type 98x designations were for Warning Combined Air & Surface with Height Finding (WCH) sets (only ones unassigned were Type 985 and Type 989).
Type 99x designations were for Warning Combined Air & Surface (WC) sets (only ones unassigned with Type 995 and Type 999).

Then a new series was brought in:
Type 102x designations were for Air Search sets (only one was Type 1022).
Type 103x designations were for Air Search/3D sets (both Type 1030 and 1031 were cancelled).

So depending on timing, zen's Bookkeeper could be Type 989 or potentially Type 1020 (sadly 1030 would be more correct but the later real 1030 steals the slot).

 

[zen]

I did speculate over Type 966....though there was such IRL.

Type 966 - Radartutorial

www.radartutorial.eu

It all depends really, as to where ASWRE came at this.

Type 985 started life as a very large rotating Electrically Scanned Array, it's possible this and NIGS are closely related in becoming four fixed arrays as ADAWS early 5 computer requirement suggests.

Small Ships Surveillance Radar however might take the 99x or 96x designation.

However Type 995 does have a nice ring about it....

 

[zen]

A wildcard thought on aircraft might alter scenarios, namely a supersonic Etendard.

https://www.secretprojects.co.uk/threads/supersonic-etendards-instead-of-crusaders.39512/

Being relatively light, compact and potentially decent performance.

 

[JFC Fuller]

Well Peter Marland's article in Warship 2022 'Post-War Radar Development in the Royal Navy' gives a handy table and some pointers.
Type 98x designations were for Warning Combined Air & Surface with Height Finding (WCH) sets (only ones unassigned were Type 985 and Type 989).
Type 99x designations were for Warning Combined Air & Surface (WC) sets (only ones unassigned with Type 995 and Type 999).

So depending on timing, zen's Bookkeeper could be Type 989 or potentially Type 1020 (sadly 1030 would be more correct but the later real 1030 steals the slot).

To be picky, things are a bit more complicated with the 1950s sets. The type numbers were generally assigned on the basis of initial role, and these were very specific. Things became confused as sets were adapted to take on additional roles, or had their roles changed, and as new sets subsumed multiple roles. And, as ever with British type designation systems the rules don't appear to have been especially fixed.

To give an example, the 98X series was for air direction, this required long range precision tracking in 3 dimensions. In the case of the Types 980/982 and 981/983 the former was for azimuth and the latter for height finding, e.g. for 3D work one of each was required. To further complicate things, these pairs could be broken-up, as was done on the Type 61 air direction frigates where a Type 982 was initially paired with a Type 277Q for height finding. These sets had to be paired with a Type 960 to provide long range warning. However, the Type 984 combined all three functions (early warning, azimuth and altitude) into a single set, which obviously carried an air direction type number. Type 985, would have had a similar role and 3D capability, as would have Type 988. Type's 986 and 987 were also both used in the air direction role but are much less interesting sets, being mash-ups of different aerials and office equipment.

Similarly, the Type 965 started life as the Small Ship Air Warning (SSAW) set, hence the Type 96X designation. But the Type 965 with the AKE(2) aerial outfit was an outgrowth to meet the Warning and Air Interception Radar (WAIR) requirement. Air Interception was really the air direction role, so by rights it should have had a 98X designation but it used the same office equipment as the 965 AKE(1) so retained that designation.

The Type 988 was an air direction set, hence a 98X designation. However, the ASWE C-band set was conceived against the Small Ship Air Warning (SSAW) requirement, the absence of either 'interception' or 'direction' in the title leads me to believe it would have had a 96X designation. Had ASWE kept to the development schedule it outline it should definitaly have been available for Bristol.

 

[zen]

Thank you JFC Fullar.

From that my suspicion of Type 966 or Type 969 doesn't seem far off.
966 was used later on.

 

[zen]

Additionally on aircraft. Gratuitous link to an old thread of mine.
Relevent to discussion of a UK F4 parallel

https://www.secretprojects.co.uk/threads/design-exercise-a-british-f-4-phantom-like-aircraft.37139/page-2

 

[uk 75]

Ark Royal was not refitted with Eagle's Type 984 which suggests that if CVA01 had been built she would have got a Bedstead (sorry radars are not my thing) like the Invincibles above the bridge.

CVA01 does not seem to have been a happy project for the designers as it had too many new innovations for a first of class ship. Given the lengthy times required to get T82,.T42, T22 and Invincible into service I suspect we would have been lucky to see CVA01 in service before 1975. Add the problems of the UK in the 70s and only one ship would have made it into service.

Added to which no navy built a conventional carrier with catapults after the Kennedy and America in the 60s.

 

[Hood]

To be picky, things are a bit more complicated with the 1950s sets. The type numbers were generally assigned on the basis of initial role, and these were very specific. Things became confused as sets were adapted to take on additional roles, or had their roles changed, and as new sets subsumed multiple roles. And, as ever with British type designation systems the rules don't appear to have been especially fixed.

Agreed, in his article Peter Marland breaks the radars down into the traditional roles we often associate them with (e.g. the early 980-series sets for fighter direction, 992 for gunnery direction). The Type designations seem to have been based on function rather than role, something that previous authors have maybe overlooked when discussing these nomenclatures.

For what its worth Peter Marland's table is listed with the following functions thus:
24x - Interrogators
25x - Transponders (IFF & beacons)
26x - X-Band sets (although 267 was 214MHz)
27x - S-Band sets (although 279 was 40MHz)
28x - 50cm sets (although 281 & 286 were not)
29x - sets (291 was 214MHz, 293 was S-band)

90x - Gunnery Aircraft, high-angle or combined low & high sets (GA)
91x - Gunnery Barrage sets (GB)
92x - Gunnery Close Range, high-angle sets (GC)
93x - Gunnery Surface, low-angle sets (GS)
94x - Interrogators (IFF)
95x - Transponders (IFF & beacons)
96x - Warning of Aircraft sets (WA)
97x - Warning of Surface Craft sets (WX)
98x - Warning Combined Air & Surface with Height Finding sets (WCH)
99x - Warning Combined Air & Surface sets (WC)

100x - Navigation sets
101x - IFF (although the cancelled 1015 was a long-range search radar)
102x - Air Search sets
103x - Air Search/3D sets
104x - Complex/Type 45