CVA-01 and Sea Harrier

[Hano]

Let us consider the following. Suppose that CVA-01 and her two sisters are built as originally planned*, entering service in, say, '72, '75 and '78 respectively. The CAG would have been, iirc, 36 jets, 18 Phantoms and 18 Buccaneers on each ship. Given that the FAA replaced these aircraft with Sea Harriers on Invincibles, it is reasonable to assume that they'd have put SHARs on their Queen Elizabeths. My question the, is how many SHARs could you reasonably fit on a Queen Elizabeth? AFAIK a SHAR has a much smaller footprint, then either a Phantom or a Buccaneer so I guess you could squeeze a lot more onboard. What do you all think?
cheers
H












*to be fair the original plan from 60-61 envisaged six carriers being built, but we'll quietly ignore that

 

[shedofdread]

If you have the capacity to launch and recover conventional aircraft, why would you need to go to SHAR? Without wishing to sound like a politician, the real question is; 'what replaces Phantom and Bucc in your timeline?'

Sorry if this strays a little (delete if thats the corrct course of action)

 

[Hano]

If you have the capacity to launch and recover conventional aircraft, why would you need to go to SHAR? Without wishing to sound like a politician, the real question is; 'what replaces Phantom and Bucc in your timeline?'

Sorry if this strays a little (delete if thats the corrct course of action)

Not at all, it's a perfectly reasonable question. My guess is that if you'd asked the FAA, they'd have loved some F-14s but I can't see the UK willing to pay for them. (Indeed I'm not sure the US would have been prepared to sell them even to the UK, but I could be wrong.) Which begs the question, what else is there in the early 80s? The French are flying, what, A-7 IIs? There was never any plan for an navalised Tornado and I've no idea if that would have been at all feasible. F-18s are in development so they're a contender but lets assume the government are keen to buy British, so as to preserve jobs, engineering skills and the like. Which leaves us with SHARs. Or better still, Harrier P.1216s - now that's an aircraft I'd love to have seen flying off a Queen Elizabeth.
cheers
H

 

[JFC Fuller]

*to be fair the original plan from 60-61 envisaged six carriers being built, but we'll quietly ignore that.

What is your source for this? Grove "Vanguard to Trident" has a 1959 Admiralty committee suggesting all five of the existing carriers be replaced one-for-one but the Admiralty itself deciding to present a request for just four to the Chiefs of Staff. There is then a stall until the Kendrew committee reports in favour of carriers in 1962 and by 1963 MoD thought it could only ask for two but the Treasury would agree only to one new carrier and two reconstructions.

 

[Hano]

*to be fair the original plan from 60-61 envisaged six carriers being built, but we'll quietly ignore that.

What is your source for this? Grove "Vanguard to Trident" has a 1959 Admiralty committee suggesting all five of the existing carriers be replaced one-for-one but the Admiralty itself deciding to present a request for just four to the Chiefs of Staff. There is then a stall until the Kendrew committee reports in favour of carriers in 1962 and by 1963 MoD thought it could only ask for two but the Treasury would agree only to one new carrier and two reconstructions.

You're quite right it was five. I was getting mixed up with the original helicopter cruiser requirements where they planned a class of six.
My understanding is that by 1963, they thought they'd get the 3 new build fleet carriers they wanted in the end, but they might have to wait a while for the 3rd. Hence they asked for two, thinking they could ask for a third when the time was ripe, probably when the time came to replace Hermes.
cheers
H

 

[JFC Fuller]

I was getting mixed up with the original helicopter cruiser requirements where they planned a class of six.

I have seen this in the odd place over the years but I have never been able to source it, do you recall where you read that six helicopter cruisers were planned?

 

[Hano]

I was getting mixed up with the original helicopter cruiser requirements where they planned a class of six.

I have seen this in the odd place over the years but I have never been able to source it, do you recall where you read that six helicopter cruisers were planned?

I can do better than that. Problem was that the new helicopters took up valuable space on the carriers but at the same time they wanted to get as many helicopters to sea as soon as possible Hence the recommendation to the Admiralty Board on April 1st 1960 was that they build:
“A class of six helicopter ships designed to carry eight helicopters each and SEASLUG ...[would allow]... us to make best use of our fixed wing aircraft in our carriers and provide an effective increase in our anti-submarine and anti-aircraft capability. Until the ASW helicopters are removed from our carriers, it will not be possible to to exploit to the full the potential of these ships and their squadrons of expensive high performance aircraft.
(The National Archive (TNA) ADM 1/27685 The Helicopter Ship: Memorandum to the Admiralty Board from DCNS and Controller of the Navy April 1st 1960.)
(I wrote my undergraduate dissertation on the genesis of the Invincible class 1960-1970 )
cheers
H

 

[CJGibson]

Were these the Type 21 cruisers I describe in The Admiralty and AEW? Six Sea Kings but could be stretched to carry a further 3 AEW Sea Kings.

Chris

 

[Hano]

Were these the Type 21 cruisers I describe in The Admiralty and AEW? Six Sea Kings but could be stretched to carry a further 3 AEW Sea Kings.

Chris

I assume you mean Study 21? The answer is yes and no. The original helicopter cruiser was first mooted in 1960. It was put on hold in late 63 because the design offices were already overworked with Polaris and CVA-01 work. The concept gets revived as part of the Future Fleet Working Party (FFWP)* and gradually evolves over a number of studies into the Invincible Class as we now know it. Study 21 was one of those interim studies, iirc c.1967.
It's worth noting that it's not clear as when the planned number in class changes. Even in FFWP they're still talking about six ships, c. 1967/68 its four and by 1970 it's down to three. Frustratingly no one's yet found any direct discussion of class numbers. That's not to say it doesn't exist, but the MOD's byzantine record keeping means that nothing has yet turned up.
cheers
H




*historians have huge difficulties with FFWP because most of the working documentation hasn't survived. All we have is the report itself and some anecdotal evidence as to its deliberations

 

[JFC Fuller]

The original helicopter cruiser concept is well known, as Hano's source document rightly points out the idea being to remove ASW helicopters from the decks of Royal Navy carriers (the Gannet had effectively been abandoned as an ASW platform in 1957 so the carriers would be reliant on other assets for ASW) thus allowing them to focus on fixed-wing aircraft operations. One suspects this was partly inspired by the lack of space on RN carrier decks and hangars (even CVA01) compared to USN platforms.

The other nice advantage was that, just as in Bristol, the AAW and ASW capabilities could be combined in a single hull that could thus contribute to the wider defence of the battle-group.

However, the last designs of the original 1960-2 series culminating in a 10,000ton ship with two Sea Dart Launchers, Ikara and 4 Chinook size helicopters (almost certainly the Westland WG.11) are mystery ships as no images of them have never been published. Personally I am skeptical that a 10,000 ton vessel could take all that.....?

 

[Hano]

However, the last designs of the original 1960-2 series culminating in a 10,000ton ship with two Sea Dart Launchers, Ikara and 4 Chinook size helicopters (almost certainly the Westland WG.11) are mystery ships as no images of them have never been published. Personally I am skeptical that a 10,000 ton vessel could take all that.....?

The Navy were skeptical as well. The last sketch designs before the programme was put on hold were for a ship of 12,000 tons carrying 4 Wessex replacements, just one Sea Dart system and a battalion of troops in emergency. Which is, what, something roughly the size of Fearless? This is long before they thought of a through deck so it's not a bad comparison.
To my knowledge, there's no images, I never found any at TNA. I'm guessing it's because at that stage, the project wasn't far enough along to bring in the artists?
cheers
H

 

[SteveO]

How many Sea Harriers could fit in a CVA-01?

Probably everyone they ever built ???

 

[Hano]

How many Sea Harriers could fit in a CVA-01?

Probably everyone they ever built ???

You're probably right Am I correct that they only built about 50 airframes? (I don't trust Wikipedia on such things)
cheers
H

 

[JFC Fuller]

You're probably right Am I correct that they only built about 50 airframes? (I don't trust Wikipedia on such things)
cheers
H

FRS.1: 24 Ordered 1975, 10 ordered 1978, 14 ordered 1982, 9 ordered 1984: Total 57

F/A.2: 31 Ordered 1988 (conversions), 18 new build and 8 conversions ordered 1994: Total 57

Total production of single seat airframes amounted to 75. There were also 8 training aircraft. Attrition was high though, 6 Sea Harriers were lost in the Falklands yet the FRS.1 fleet had shrunk by a total of 18 airframes by the early 90s. Worth remembering that they only ever equipped two front-line FAA squadrons.

Please feel free to correct me if my maths is wrong.

 

[Hobbes]

I just compared 1:72 scale models of the SHAR FA.2 and the Buccaneer. The Harrier is ~30% shorter, but it's a bit wider than a Bucc with folded wings. So for parking along the deck edge the Bucc is better. The total deck area covered by them (spotting factor) is a bit more complicated to find out.

 

[royabulgaf]

Okay, if I may go off thread by going back on thread. Assume there are three ships built in the class. You are then looking at about 75 Phantom replacements, and 75 Buccaneer replacements. in the mid-late 70s timeframe.

1. With the 01s, it seems like there would be no Harrier, and instead an RAF only P1154.
2. The Yanks had the perfect carrier aircraft perhaps ever in the Phantom. The F-111B was a flop, and the F-14 perhaps too large for the 01s. Hopefully, the RN took the F111 lesson to heart and did not try anything stupid like a navalized Tornado. British built Phantoms seem like the best idea, or maybe a Phantom for 1154s for the USMC?
3. For the Buccaneer replacement, was there not a navalized Jaguar?

 

[Abraham Gubler]

If the RN acquired CVA-01s they wouldn’t need Sea Harriers as they could fly their F-4K Phantoms from their new carriers. They wouldn’t need new fast jets until the 1980s when the Buccaneers would need replacement. If the British aerospace industry had suffered the same cancellations in the 1960s in CVA Universe as they did in ours then the likely next RN jet program would be a naval Tornado. Which in IDS and later ADV (to replace F-4K) versions could be an excellent fit to the RN’s needs assuming it could be built to operate at the low take-off and landing speeds required for the RN. I wouldn’t be too quick to assume they would acquire USN aircraft because RN carriers needed slower flying jets for their carriers. Which is why they built the F-4K rather than just off the self F-4Js.

 

[Hood]

I don't buy into the Sea Tornado for several reasons;

The Sea Tornado would have had to been designed in the early 1970s when Tornado itself was developed, that puts it in the same timeframe in both design and first flights as the F-18 Hornet. The ADV began devlopment in 1976 and was only 80% common to the IDS, a navalised version would differ even more. The ADV entered service in 86 but wasn't fully debugged until after then. A marine version would perhaps not be ready until 87-89.
The design of a navalised Sea Tornado would require British design leadership and Panavia's European partners would not have had the need or desire to push this aircraft through. Given the UK/ Italian need for ADV was more pressing, and BAe's work on the ADV variant, any development of a Sea Tornado would take secondary priority.
So the government would have to make a conscious decision to develop three variants of the Tornado from the start, in fact that might have not only altered the basic design of the Tornado but would leave the UK footing the bill for developing the ADV and Sea Tornado. Would the Treasury and MoD of the late 70s and early 80s really have funded three variants at once? ADV relied on Saudi Arabian exports to recoup some costs but prospects of exports for a Sea Tornado are practically nil. Would Panavia even have gotten started had the UK pushed too far from the start for changes and a naval variant?

It's more likely the FAA, always being the cinderella service compared to the RAF, would have been told to get on with the F-4K/ Bucc and then arrange a replacement ad hoc when the Phantom fleet was too old to carry on and the replacement for CVA was still likely to be 10-15 years away. Then off the shelf would be the only answer. Re-opening and redesigning Tornado during the late 80s ore early 90s would be too late and costly. Some of BAe's small fighter projects like the P.1110 look promising but still for a solo project with no sales prospects its a non-starter. My ultra what-if would be the EAP built as a proper solo UK fighter analogous to the Rafale with a naval variant but thats not really practical either in any sense.
So its easy to see the F-4K and Bucc lasting until 1993-95, by then the end of the Cold War means 1-2 carriers chopped (assuming all three in this sceanario survive the 1975 and 1981 defence cuts), the air fleets drastically reduced, perhaps a small buy of F/A-18C and D Hornets in 1990-92. And by then the RN is looking at replacing CVA anyway so probably would stick to a joint fighter and strike-fighter F/A-18 fleet.

For a hypothetical drawing here is link a profile I did with another artist over at Shipbucket. In the thread we discussed various alternatives for replacement aircraft. Page 1 has a profile of CVA-01 with the original airwing.

http://www.shipbucket.com/forums/viewtopic.php?f=13&t=2039&start=40

 

[Abraham Gubler]

The Sea Tornado would have had to been designed in the early 1970s when Tornado itself was developed, that puts it in the same timeframe in both design and first flights as the F-18 Hornet. The ADV began devlopment in 1976 and was only 80% common to the IDS, a navalised version would differ even more. The ADV entered service in 86 but wasn't fully debugged until after then. A marine version would perhaps not be ready until 87-89.

If the UK had built the CVA-01s and not the TSR.2 it is still very likely they would have joined/formed the Tornado program. So in this situation why would they not decide to take advantage of the multi role nature of the Tornado to fund a Buccaneer replacement? Doing so would be cheaper than going it alone on a Buccaneer replacement and still maintain the advantages of domestic development and production. To date the UK has only initiated a major aircraft acquisition via foreign purchase through the Apache (as a level 1 partner the F-35 counts as a co-development). They have only turned to foreign (ie US) aircraft when their own initial project has failed (F-111K, F-4K, C-130) or as a temporary gap fill (B-29, Sabre).

Incorporating a naval strike variant in the Tornado program would not be too difficult considering the short field requirement and the initial wide variance in versions planned by the partners (German single seat aircraft). The mission requirement and schedule for the IDS would align with a Buccaneer replacement and later the ADV with a F-4K replacement.

As to the mechanics of delivering a Sea Tornado the UK aerospace industry would have HS Kingston and Blackburn in the 1970s without a development project and no fighter production in the 80s once they have finished the RAF’s P.1154 (assuming it was not cancelled). So there would be ample capability to design and build the aircraft. Which would have all the advantages of using the same engine and avionics as the other Tornados. All it would need is probably a blown wing, new gear and a strengthened structure. They might even have a customer from day one with the Marineflieger signing up especially if the wider variance in Tornado versions meant the Luftwaffe stayed with a single seat Tornado.

Even without the sea Tornado I can’t see the F/A-18 as being such a lay down misere for the RN. Could the F/A-18 even operate from the CVA-01 at combat loads? It was designed for the faster American supercarriers.

 

[zen]

F/A 18 Should be OK for CVA-01. The recovery zone's length, and catapults are all good enough to cope with a F14.


That all said Tornado is very likely to be navalised as the RN would be involved in the MRCA as they had in the UKVG and earlier AFVG.


Possibility is however that the RN and RAFs requirements could make it less attractive for the other members to join up.

 

[JFC Fuller]

CVA01, despite not being a super carrier, was a sizeable vessel. Length was 928ft at flight deck level and there would have been considerable scope for enlarging the flight deck if the Sea Dart system was removed (about 15%), she was also intended to provide at least 25 knots whilst operating catapults and give a sustained 28 knots in the tropics (this was apparently deep and dirty too). The design target was to enable aircraft launches up to 60,000lbs or more. Given that the Midway class, roughly the same size if not smaller, were able to operate both Phantoms and F/A-18s I see no reason why a CVA01 could not, indeed USS Coral Sea carried the first deployment of the Hornet to the Med and used them in action over Libya whilst USS Midway made the last ever USN Phantom launches. Charles de Gaulle, also smaller than a CVA01 has cross-decked F/A-18s too (though there may have been weight limits?).

The wider problems with a Sea Tornado is that the ADV is decidedly mediocre interceptor let alone a tactical fighter, it would actually make a pretty poor replacement for a Phantom being used in the tactical fighter role- which is why it only replaced RAF interceptor Phantom Squadrons and not the two Phantom squadrons in Germany. The idea of Tornado as multi-role is really a misnomer, it was an aircraft designed as a dedicated light bomber which got shoehorned into the interceptor role (with considerable changes, as Hood said only 80% commonality) and was only average at it. The initial wide difference between variants ultimately evaporated as well with all countries taking the same basic IDS variant.

If one really wants a British origin aircraft it might be better to look at the P.1216 series and move away from catapult launch altogether, it's theoretically a much more multi-role aircraft, it can ride the UK defence boom of the 1980s rather than slogging through the downturn of the 70s and it was actually proposed to the RN in the real world anyway.

 

[Graeme65]

If you add another 1500 to 2000 lbs to the Tornado in navalising it, how would that work with a single engine approach-bolt performance? Was that not the Achillies' heel of the Sea Jaguar.

Given the cost added to a UK only Tornado variant by the need for carrier capability I can well see the RN wanting to jump ship to Hornet with the RAF holding the door open.

 

[zen]

I seem to reccal reading the deck catapults and arrestor gear was aimed at 70,000lb+ aircraft, thats F14 territory.


No plating over the Sea Dart position is not viable in the design, as it needs too much overhang right at the stern for the periode. Besides which it doesn't need it.


IF.....if the RN FAA is having input into the MRCA, then its going to be more like UKVG or AFVG or even the earlier OR.346 proposals. Closer to being something like the F111 or F14.
RAF wanted longer range, RN would want more power too, compatibility with German and Italian requirements looks less, not more likely. PANAVIA may well never get off the ground, and the UK would have to go it alone.

 

[Hobbes]

If you add another 1500 to 2000 lbs to the Tornado in navalising it, how would that work with a single engine approach-bolt performance? Was that not the Achillies' heel of the Sea Jaguar.

Seems to me it would do better than e.g. a Buccaneer or other older aircraft. If it didn't stop the FAA from acquiring those aircraft, why would it be an issue for the Sea Tornado?

 

[Hano]

ignoring the politics for a moment, I'm curious as to how difficult would it have been to engineer a Sea Tornado? At both design or a later stage.
I appreciate the F3 was a lousy tactical fighter, but was under the impression it was a reasonable long range interceptor. Which would have been ok for the FAA as it's job would then be to knock down Backfires before they were in range to launch their missiles at the Fleet. As a naval Buccaneer replacement it would, I guess have been a reasonable replacement, certainly not a step backwards.

 

[shedofdread]

Once again, I hope I don't have my timelines in a twist (a dreadful complaint if ever there was one... ) but if you have a big carrier from which you fly Buccs, wouldn't P150 (supersonic Buccaneer) have rather appealed hence no need for MRCA / Tornado?

Folding wing version for FAA use and non-folding (slightly lighter) for RAF. The non-folding one could still use the stronger, naval structure - hence longer airframe life. A few updates along the way and it wouldn't difficult to see such a platform lasting until replaced by Typhoon (or in this alternate world would there have been Typhoon???).

 

[JFC Fuller]

Zen,

I have seen the 70,000lb figure several times but the best sources I have seen use 60,000lbs so I tend to use 60,000lbs plus. I believe its Captain Brown (Deputy Director Naval Air Warfare 1961-4) who first gave the 70,000lb figure in a 1967 article. I agree about not needing to extend the flight deck rearwards but I really see nothing preventing the stern ultimately being rebuilt with a longer deck and hangar if it was ever required.

Tornado F.3, reasonable, certainly not stellar. Tornado IDS, range aside its a good strike aircraft.

BAE found that just making the Typhoon suitable for STOBAR would add 500kg to the aircraft (and that was just a study, who knows how that would have escalated if they actually tried it) and that making it catapult capable would make it completely uncompetitive. One likely issue for Tornado is displacement of internal equipment in the nose where it is already tightly packed, the GR.4 standard aircraft had to sacrifice a 27mm cannon in order to take the FLIR that came with the upgrade. Adding a substantially beefed up undercarriage to allow catapult launchings is liable to cause significant problems.

 

[CJGibson]

Ah, you will like Battle Flight. Lots on the MRCA(AD) , which is a very interesting story. I started from the "ADV is rubbish" standpoint and finished with the view that it was a bespoke vehicle for disrupting Backfire operations. More Daniel Day-Lewis than Tom Cruise.

Chris

 

[CJGibson]

Forgot to say, didn't need a carrier version of the ADV as to do its job it had an unsinkable one to fly from. ; Airstrip One.
Chris

 

[CJGibson]

Have you nicked a copy of Battle Flight by any chance?

Chris

 

[Hano]

um, Battle Flight?
cheers
H

 

[Abraham Gubler]

CVA01, despite not being a super carrier, was a sizeable vessel. Length was 928ft at flight deck level and there would have been considerable scope for enlarging the flight deck if the Sea Dart system was removed (about 15%), she was also intended to provide at least 25 knots whilst operating catapults and give a sustained 28 knots in the tropics (this was apparently deep and dirty too). The design target was to enable aircraft launches up to 60,000lbs or more. Given that the Midway class, roughly the same size if not smaller, were able to operate both Phantoms and F/A-18s I see no reason why a CVA01 could not, indeed USS Coral Sea carried the first deployment of the Hornet to the Med and used them in action over Libya whilst USS Midway made the last ever USN Phantom launches. Charles de Gaulle, also smaller than a CVA01 has cross-decked F/A-18s too (though there may have been weight limits?).

The big difference between Midway and CVA-01 is not ship size and aircraft weight but in ship and aircraft speed. US carriers were a good five knots faster than British carriers for flight operations and their catapults and arrestor gear designed for higher speeds. The higher ship speed means more wind over deck and the higher landing and take-off speeds of the aircraft means much higher force loading on the launch and recovery gear (force equals half of weight times speed squared: therefore increases in speed has exponential effect on force). This is why the RN built the F-4K rather than taking off the shelf F-4Js because they needed a Phantom that could fly slower to operate from their carriers.

So if the RN is going to acquire the F/A-18 it will have to be made compatible to their carriers which means being able to launch and recover with impulse. And apart from this issue is the F/A-18 (or more likely A-18) really compatible with Buccaneer replacement. If sourcing from the USN I would imagine the A-6E would be more compatible with the Buccaneer mission being a two seat, long range aircraft. The A-6 is also more likely to be operable at the lower landing and take-off speeds required by the RN.

If one really wants a British origin aircraft it might be better to look at the P.1216 series and move away from catapult launch altogether, it's theoretically a much more multi-role aircraft, it can ride the UK defence boom of the 1980s rather than slogging through the downturn of the 70s and it was actually proposed to the RN in the real world anyway.

But the P.1216 only existed in our real world because of 15 years of events after the cancelation of the CVA-01. Without those events it’s unlikely that the same requirement would have eventuated. Especially since the RN would have been thinking in the 1970s seriously about a replacement for the Buccaneer for their three strike carriers.

 

[Abraham Gubler]

If you add another 1500 to 2000 lbs to the Tornado in navalising it, how would that work with a single engine approach-bolt performance? Was that not the Achillies' heel of the Sea Jaguar.

I would imagine a Sea Tornado (or would it be Sea Panther) would need more powerful engines because to get the landing speed down would probably have blown wings. Which could see the RB.199 designed for a 60 kN rather than 40 kN requirement.

Given the cost added to a UK only Tornado variant by the need for carrier capability I can well see the RN wanting to jump ship to Hornet with the RAF holding the door open.

If the carrier requirements are incorporated from the start in the baseline (as in the Rafale) the additional cost of the aircraft specific to the RN would be minimal. With the added advantage of extra capability for the air force versions of the Tornado (shorter takeoff and landing: blown wings, more powerful engine: 60 vs 40 kN). As to the RAF being interested in the Hornet they would have the P.1154 in production in the 1970s which could very well be a competitor to the F-16 and Hornet.

 

[JFC Fuller]

The speed difference between a Midway and a CVA01 would be negligible and certainly not 5 knots. CVA01 was designed for a maximum speed of 30 knots, a sustained speed of 28 knots and at least 25 knots during aircraft operations; however these figures were for the vessel 6 months out of port and deep and dirty in the tropics so straight out of the yard she would have done much more. Whilst the Midway class would do 33 knots at full flank speed, "At that speed the ship really acted funny. It would vibrate to the point you could hear silverware shaking" ( http://usscoralsea.net/1mc/index.php?topic=1.0 ) it was the trials speed straight out of dock. Thus it would be fair to say that both types would have a very similar top speed. Equally, both will have similar steam requirements for their catapults so would have suffered a similar loss in speed from catapult operation. Ark Royal / Eagle, at most had a real world speed deficiency compared to the Midway class of about 2 knots: the ships real weakness was that their catapults operated at a lower pressure and over shorter strokes than their US equivalents meaning they produced less power. It was that weakness that F-4K was designed to overcome by carrying more installed thrust, thrust that was then angled downwards in the airframe and the aircraft itself given a very high angle of attack at take-off through the double extending nose gear.

Furthermore, CVA01 was to have had catapults and arresting gear unique to her, her two BS6 catapults were to have been 250ft long compared to 199ft for the BS5A installed on Ark Royal (and she only had one of those, her other catapult was a regular BS5). Her arrestor gear was also to have been a new design from the RAE which would have provided a constant wire pull out for any entry speed or landing within the systems performance envelope. The F-4J was already able to land on Ark Royal so CVA01 should not have been a problem.

The problem of adding carrier requirements into the Tornado from the beginning is it starts to make the aircraft less attractive to Germany and Italy who are going to be unwilling to contribute to the development of features that are only needed to provide a carrier variant. Tornado politics were fraught enough as it was. The P.1154 would probably have never entered service anyway, the design increasingly looks like it would have been approaching extreme technical difficulties as Dr Michael Pryce explained in his lecture. The Royal Navy budget was under extreme pressure throughout the 70s and the 80s, more so than the Army and Navy so anything that reduces cost would be attractive whilst the relatively small air wing of a CVA01 would make a genuinely multirole type attractive.

 

[Abraham Gubler]

The speed difference between a Midway and a CVA01 would be negligible and certainly not 5 knots.

Not so. Unless you can document that the Midway class after SCB-101.66 was limited to a maximum speed with catapults steamed of less than 30 knots you have not presented a convincing argument. The problem with trying to backwards analyze things is the huge vulnerability to scenario fulfillment. And I don’t see that your arguments are convincing as the various issues you have raised are actually explained by other factors not boiler capacity.

CVA01 was designed for a maximum speed of 30 knots, a sustained speed of 28 knots and at least 25 knots during aircraft operations; however these figures were for the vessel 6 months out of port and deep and dirty in the tropics so straight out of the yard she would have done much more.

She may have been faster than 25 knots with catapults steamed while fresh from a yard hull scrapping with no stores onboard in cool waters but that doesn’t mean you can operate aircraft needing more than 25 knots wind over deck (WOD). Because what happens after six months of marine growth with a full load of stores on a hot, still day and your speed drops down to 25 knots! You can’t launch your aircraft. And that didn’t work out so well for the Argentineans in 1982. The RN expected its aircraft to be launched from their carriers with at most 25 knots WOD. Period.

Whilst the Midway class would do 33 knots at full flank speed, "At that speed the ship really acted funny. It would vibrate to the point you could hear silverware shaking" ( http://usscoralsea.net/1mc/index.php?topic=1.0 ) it was the trials speed straight out of dock.

The ship is not topping out at 33 knots because of a limit in boiler capacity if she is shaking! That’s a limit in either or all of the hydrodynamics, turbines, shafting, propellers and rudders.

Thus it would be fair to say that both types would have a very similar top speed. Equally, both will have similar steam requirements for their catapults so would have suffered a similar loss in speed from catapult operation.

Absolutely not. The top speed of the CVA-01 was 30 knots and the top sustained speed was only 28 knots. Because this was something they knew would happen from design it would appear to be the difference between running the boilers at above normal temperatures to gain two extra knots. They would have to drop back to 27-28 knots to avoid melting the piping. The speed drops when the catapults are steamed only if the ship does not have a surplus of steam generation. I’ve been to sea on two USN carriers (one nuclear and one oil fired) and they didn’t drop a knot when they piped steam to the catapults.

Ark Royal / Eagle, at most had a real world speed deficiency compared to the Midway class of about 2 knots:

Where is this documented?

Furthermore, CVA01 was to have had catapults and arresting gear unique to her, her two BS6 catapults were to have been 250ft long compared to 199ft for the BS5A installed on Ark Royal (and she only had one of those, her other catapult was a regular BS5). Her arrestor gear was also to have been a new design from the RAE which would have provided a constant wire pull out for any entry speed or landing within the systems performance envelope. The F-4J was already able to land on Ark Royal so CVA01 should not have been a problem.

No doubt the catapults and arrestors on the CVA-01 would be much better than the Ark Royal but she is still looking like a step down compared to contemporary USN carriers. The USN could afford to have the Hornet come in at a >140 knot approach speed (way above the 115-125 knot requirement) because their carriers could launch and recover heavier and faster aircraft. It’s noteworthy that an empty Hornet moving at 140 knots generates the same force of an empty F-4K moving at 120 knots.

Now I don’t have in front of me information on MLS, weights and approach speeds for the F-4K, Hornet and so on to make a fully informed call. But the Hornet required much higher MLS and approach speeds than what the RN was flying (F-4K and Buccaneer) and this was not going to be good when it comes to working out if you can fly them operationally (as opposed to cross decking) even if empty it is only 77% of the weight of an F-4K.

 

[JFC Fuller]

Not so. Unless you can document that the Midway class after SCB-101.66 was limited to a maximum speed with catapults steamed of less than 30 knots you have not presented a convincing argument. The problem with trying to backwards analyze things is the huge vulnerability to scenario fulfillment. And I don’t see that your arguments are convincing as the various issues you have raised are actually explained by other factors not boiler capacity.

Not so unless you provide a source saying the Midway class could sustain over 30 knots whilst intensively using cats.

She may have been faster than 25 knots with catapults steamed while fresh from a yard hull scrapping with no stores onboard in cool waters but that doesn’t mean you can operate aircraft needing more than 25 knots wind over deck (WOD). Because what happens after six months of marine growth with a full load of stores on a hot, still day and your speed drops down to 25 knots! You can’t launch your aircraft. And that didn’t work out so well for the Argentineans in 1982. The RN expected its aircraft to be launched from their carriers with at most 25 knots WOD. Period.

The point was that the RN generally quoted ship speeds deep and dirty whereas USN ship speeds are generally clean trials speeds thus the difference is nowhere near as stark as you suggested though if you have a source to support the 5 knot figure I would love to see it.

The ship is not topping out at 33 knots because of a limit in boiler capacity if she is shaking! That’s a limit in either or all of the hydrodynamics, turbines, shafting, propellers and rudders.

I never said she was topping out because she was shaking, I was simply pointing out how she behaved at that speed.

Absolutely not. The top speed of the CVA-01 was 30 knots and the top sustained speed was only 28 knots. Because this was something they knew would happen from design it would appear to be the difference between running the boilers at above normal temperatures to gain two extra knots. They would have to drop back to 27-28 knots to avoid melting the piping. The speed drops when the catapults are steamed only if the ship does not have a surplus of steam generation.

Do they? Where is this documented? The CVA01 design requirements were clear that they were the required speeds. Do you have a source saying that 30 knots required running the boilers above normal temperature to the point where it would melt pipes?

Where is this documented?

Where is it documented that it is not?

No doubt the catapults and arrestors on the CVA-01 would be much better than the Ark Royal but she is still looking like a step down compared to contemporary USN carriers. The USN could afford to have the Hornet come in at a >140 knot approach speed (way above the 115-125 knot requirement) because their carriers could launch and recover heavier and faster aircraft. It’s noteworthy that an empty Hornet moving at 140 knots generates the same force of an empty F-4K moving at 120 knots.

Actually she looks spot on if not better than Midway and Coral Sea which both operated Phantoms and Hornets.

Now I don’t have in front of me information on MLS, weights and approach speeds for the F-4K, Hornet and so on to make a fully informed call. But the Hornet required much higher MLS and approach speeds than what the RN was flying (F-4K and Buccaneer) and this was not going to be good when it comes to working out if you can fly them operationally (as opposed to cross decking) even if empty it is only 77% of the weight of an F-4K.

Accept the F-4K was really designed around the limitations of the Eagle and Ark Royal, CVA01 was a far more capable ship designed from the outset with modern steam cats in mind (and much larger ones than that) and much heavier aircraft (60-70,000lbs).

 

[Abraham Gubler]

The problem of adding carrier requirements into the Tornado from the beginning is it starts to make the aircraft less attractive to Germany and Italy who are going to be unwilling to contribute to the development of features that are only needed to provide a carrier variant. Tornado politics were fraught enough as it was.

But on the reverse it may change the scope of the project to more like the F-35 with several versions each sharing common systems. In which case the politics of finding a common specification are defused. So instead of the Tornado IDS being developed you have the Tornado RN/MFL Naval Strike, Tornado Luftwaffe Tactical Fighter, Tornado RAF Tactical Strike and Tornado Aeronautica Militare whatever they wanted. With the UK looking forward at a Tornado in RAF and RN interceptor versions.

The P.1154 would probably have never entered service anyway, the design increasingly looks like it would have been approaching extreme technical difficulties as Dr Michael Pryce explained in his lecture. The Royal Navy budget was under extreme pressure throughout the 70s and the 80s, more so than the Army and Navy so anything that reduces cost would be attractive whilst the relatively small air wing of a CVA01 would make a genuinely multirole type attractive.

The problem with applying this thinking is the alternate history scenario has obviously changed some things such as the increased funding for the RN to sustain and recapitalise the carrier force. Maybe Harold Wilson was a Navy man in this universe or whatever. Hano who asked this question even posited that all three CVA-01s were built in which case the RN would have brought the full 150 odd F-4Ks, another batch of Buccaneer S.2s and a new AEW aircraft (plus more Type 82 destroyers and maybe even the escort cruiser and so on).

So the RN carrier force isn’t going to face a threat until Thatcher. Which was a pretty extreme threat but by then the Buccaneer replacement program would be in production. So with this kind of historical situation the funding crisis of the 1970s for the RN (but not the HMG) have been done away with by the same stroke as the 1960s crisis that enabled the CVA-01 to be built.

 

[Abraham Gubler]

Where is it documented that it is not?

The point of proof is to establish that something exists. Otherwise you can safely assume that it doesn’t.

“Absence of evidence is not evidence of absence.”

Or
argumentum ad ignorantiam as the Romans would say

 

[JFC Fuller]

The point of proof is to establish that something exists. Otherwise you can safely assume that it doesn’t.

“Absence of evidence is not evidence of absence.”

Or
argumentum ad ignorantiam as the Romans would say

Eloquently put, and precisely why I would love to see a source supporting the 5 knot figure.

 

[Abraham Gubler]

Eloquently put, and precisely why I would love to see a source supporting the 5 knot figure.

I’d say it’s a fair call based on the operational specs of all USN carriers and aircraft built since the 1950s. That is an at least 30 knot catapults steamed aircraft launching speed.