It's 1948...or maybe 1945. What would you do with Implacables / Illustrious carriers ?

[JFC Fuller]

To pick up on the Majestic/Colossus with Seamew and/or Type 191 aspect again. In the 1950s there were multiple carriers involved in various trials and training roles:

Dartmouth Training ship: Triumph replaced the cruiser Devonshire in 1953 but was retired in 1955 without replacement
Home Fleet Training Squadron: Two carriers, Implacable and Indefatigable from 1951 to 1955 when they were replaced by Ocean and Theseus (actually used as helicopter carriers during Musketeer)
Trials and Training Carrier: One carrier, Illustrious, then Bulwark and then Warrior with the role abolished in 1957

Carriers in the reserve fleet, (e.g. Indomitable, Implacable and Indefatigable from 1955) tended to be in class III status, de-stored and and at extended notice on the basis they had serious defects or required significant work to be useful. As such, class III was a sort graveyard status where ships deteriorated until they were sold for breaking.

The RNVR squadrons and their Seamews, Gannets, Attackers and Sea Hawks would, on mobilisation, have embarked on the three to four carriers active in the trials and training roles, until the RNVR was abolished and its squadrons disbanded in 1957.

 

[uk 75]

Thanks JFC . 1957 is when the UK decides that ballistic missiles and the H Bomb (super-bombs) make fighting a war impossible once nuclear weapons are used and gets rid of the forces you mention.
From then until 1966 the RN uses the need to defend "East of Suez" as the justification for its carrier and amphibious warfare forces.
It is only after 1962 when NATO adopts "flexilble response" that the Atlantic ASW role again becmes important, to ensure that US reinforcements can reach W Europe. The demise of TSR2 and CVA01 is not just beause of cost, they do not fit in this new role

 

[Archibald]

Thanks for the explanation(s).
If I were to compare to France carrier force, the differences would be as follow
- we still need carriers to defend overseas territories (essentially in South America, Caribbean. La Réunion by contrast is remote from everything bar very empoverished Madagascar)
- also past colonial relics in the Mediterranean (Algeria to Lebanon) and Françafrique.
- De Gaulle threw a (partial) middle finger at NATO in 1966, so screw that ASW thing
- the carriers managed to find themselves a role in the nuclear force: AN-11/22/52 strapped to the Etendard IVs
(later ASMP on Super Etendard)

France certainly had ASW large platforms - but nothing like the Centaurs or Invincibles. The largest ASW ships were a diverse lot: Colbert cruiser, Jeanne D'Arc helicopter carrier, the old Arromanches (until 1974); along with classic frigates of course. Not unlike the Centaurs commando carriers & Tiger mix in the 60's - but fewer of them.
Interestingly enough, Jeanne d'Arc hull form derived from Colbert, itself a much uprated De Grasse (1955 instead of 1935). De Grasse was too old for conversion into a missile cruiser and ended as a nuclear command ship for Moruroa after 1966 and until 1974.
De Grasse, Colbert, and Jeanne d'Arc - only loosely related - were the last three 10 000 tons+ cruisers France ever had.

 

[Foo Fighter]

Keep the best, scrap the rest and build new as soon as possible with best practice/upgradability.

 

[uk 75]

Interestingly France does develop the Super Frelon helicopter with ASW, troop carrier and anti ship missiles which would have been a useful bit of kit for the RN but was too early for the big helo deal.

 

[EwenS]

Replacement for the licence built Sikorsky S-58 in the French forces. SE.3200 Frelon first flew 1959 but only as prototypes. SA.3210 Super Frelon ff 1962 and entered service 1965.

Westland produced licence built versions of the Sikorsky S-55 as the Whirlwind and the S-58 as the Wessex with the HAS.1 entering service in 1961. The HAS.3 was the most advanced A/S helicopter in the world when introduced to service in 1967.

Sikorsky S-61 Sea King ff 1959 and entered service with the USN in 1961. Similar size to the Super Frelon. Westland got a licence for it shortly after it first flew and the MoD placed the first order in 1966. HAS.1, which basically had the Wessex HAS.3 avionics fit, ff 1969 and entered operational service the following year.

So the timelines are not so dissimilar.

 

[DWG]

The Seamew is odd. That it was to be operated from escort carriers is often used as a throwaway remark but suffers from the flaw that there were no escort carriers (aside from Campania). More likely, it was intended that the RNVR squadrons equipped with it would be mobilised to operate from the trials and training carrier and the various ships in reserve (e.g. Illustrious in 1955/56).

The Putnam Shorts book makes it clear that the driving factor behind Seamew was Rear Admiral Matthew Slattery, first as Chief of Naval Air Equipment, and then as Joint MD of Shorts. Apparently he didn't like the growth in aircraft weight and complexity, and thought it was making Naval Air inaccessible to the smaller NATO nations, and basically drove the creation of the requirement for what became Seamew. So the smaller decks it might be applied to would include every carrier operated by a NATO nation, or ships that might be acquired by NATO nations if they didn't have to fork out for something the size of a Light Fleet or larger.

And of course it was also supposed to have a Coastal Command role.

 

[EwenS]

The Coastal Command need for the Seamew was borne out of Admiralty concern about Soviet subs mining British inshore waters and the consequent need for shorter range AS aircraft. Confusingly, the RAF officer responsible was Air Commodore Harold Satterly, Director of Operational Requirements. The RAF reluctantly ordered the Seamew MR.2 in 1955 as part of a joint RN/RAF order.

I love the quote about it from a test pilot.

“Access to the cockpit is difficult. It should be made impossible”

 

[Hood]

The Coastal Command need for the Seamew was borne out of Admiralty concern about Soviet subs mining British inshore waters and the consequent need for shorter range AS aircraft. Confusingly, the RAF officer responsible was Air Commodore Harold Satterly, Director of Operational Requirements. The RAF reluctantly ordered the Seamew MR.2 in 1955 as part of a joint RN/RAF order.

I love the quote about it from a test pilot.

“Access to the cockpit is difficult. It should be made impossible”

Coastal Command did consider inshore MR aircraft at least twice during the early 1950s for attacking MTBs, coastal craft and small submarines inshore. Ultimately there was no cash for those plans (nor no real threat to justify it) and of course the helicopter offered the better inshore capability. Coastal Command was down for 4 Type 193 helicopters, a rather odd number, I presume these would have been used for tactical trials at the Joint ASW School and ASWDU. Never seen any evidence more than 4 were planned for, which seems odd to go to all the expense of complicating the Type 191 programme for the sake for a handful of helicopters.

Plus there were the tussles over the Inskip Award, a tale for another thread methinks!

 

[Siberia]

As said in the tin. With perfect hindsight (Victorious horror story) the Centaur-class look like a much better long-term bargain... Could some of the six Illustrious-class be passed to a foreign navy? How could the Victorious siliness be strangled in the cradle? Long term effects?

Well with perfect hindsight we know that turbines are going to rapidly displace reciprocating engines, that developments such as steam catapults, angled flight decks, optical landing systems etc. are vital to aircraft carrier operations, and that aircraft are going to be rapidly growing in size so need to be taken into account in designs. I'm assuming that in terms of decisions what we say goes, within reason.

Keep the four Illustrious-class carriers operating but other than adding optical landing systems to each don't do anything major to them, they're going to be decommissioned as soon as possible. I'm in two minds about the Implacable-class – on the one hand they became training ships only a few years down the line, on the other updating them would make for more realistic training. On balance I'd say fully modify them – angled flight deck, steam catapults, optical landing system – as they make for a decent reserve and more realistic training. I'm open to being convinced otherwise though. I doubt that you'd be able to sell any of them on, the manpower requirements and running costs would be too great for most foreign navies.

Scrap the Audacious-class, Eagle has already launched which is a bit of a bugger but Ark Royal is still building. Either way it helps free up resources and a slipway. This clears the way for a brand new aircraft carrier design in the future, something like the 1952 one or if you're feeling really adventurous getting on for Kitty Hawk-class size. If legacy facilities constrain the designs then better to enlarge the bases to get the maximum effective ship. Ideally you'd build five of them so as to always have at least three available, IIRC the official estimates for the time included five carriers, but realistically four seems more achievable.

For the Centaur-class pause all work whilst you figure out what the optimum angle for the flight deck is, how to add steam catapults and optical landing systems. You want them to be able to operate basic jet fighters and attack aircraft. At the same time look to see what sort of modifications can be made to help when carrying helicopters and Royal Marines in the commando carrier role.

 

[PMN1]

On the infrastructure side, anyone know when the RN stopped using lots of shoring to prop up ships in dry-dock?

The amount of shoring needed, along with the amount of water needing to be pumped were two reasons for keeping the docks narrow as late as 1892....along with cost.

These were also the reasons for the heavily stepped or altared sides of the early docks compared to later ones.

 

[alertken]

#45, 46 (Super) Frelon. The shufflings that preceded Gazelle+Puma=Lynx included SA.3210. That had a FIAT-variant of S.58 (=Wessex) transmission (just as WAL's first attempt at a large heli, WG.6/7 Westminster had S-56, then S-64 rotor/gearbox). No-body in UK could dismiss Frelon on any technical grounds, so the reason accepted by Ministers was that SH-3D had, as Frelon did not, compatible ASW practice.

 

[Archibald]

Even in France, Super Frelon was pushed on the wayside by Puma. Too big, too complex, too expensive - never achieved its full potential.
Except in Israel and of course, in China: the Z-8...

 

[Hood]

Super Frelon was assessed under NASR.358 but it was rejected because it had insufficient flying crane payload capacity for the RAF, didn't meet the ferry range requirements and its physical dimensions were too large, even when the rotor blades were folded.

Super Frelon does indeed look like one of these aircraft that just never fulfilled its promise fully, just too big and complex (therefore expensive too) sadly.

 

[NOMISYRRUC]

To pick up on the Majestic/Colossus with Seamew and/or Type 191 aspect again. In the 1950s there were multiple carriers involved in various trials and training roles:

Dartmouth Training ship: Triumph replaced the cruiser Devonshire in 1953 but was retired in 1955 without replacement
Home Fleet Training Squadron: Two carriers, Implacable and Indefatigable from 1951 to 1955 when they were replaced by Ocean and Theseus (actually used as helicopter carriers during Musketeer)
Trials and Training Carrier: One carrier, Illustrious, then Bulwark and then Warrior with the role abolished in 1957

Carriers in the reserve fleet, (e.g. Indomitable, Implacable and Indefatigable from 1955) tended to be in class III status, de-stored and and at extended notice on the basis they had serious defects or required significant work to be useful. As such, class III was a sort graveyard status where ships deteriorated until they were sold for breaking.

The RNVR squadrons and their Seamews, Gannets, Attackers and Sea Hawks would, on mobilisation, have embarked on the three to four carriers active in the trials and training roles, until the RNVR was abolished and its squadrons disbanded in 1957.

Are these of any use?



Op-CV = Operational Fleet Carrier
Op-CVL = Operational Light Fleet Carrier
Op-BB = Operational Battleship.
AMS = Aircraft Maintenance Ship (i.e. Unicorn)
AR = Heavy Repair Ship (i.e. Triumph)

​

Triumph was replaced by the Dartmouth Training Squadron, which consisted of a destroyer and 2 frigates. That is, according to Leo Marriott in Royal Aircraft Carriers 1945-1990. The Dartmouth Training Squadron was a victim of the Mason Defence Review of 1974-75. It's role was assumed by the Dartmouth Training Ship which which was initially provided by rotating Fearless and Intrepid. Fife relieved them in the late 1980s, but she was sold to Chile and her place was taken by Bristol.

 

[NOMISYRRUC]

As said in the tin. With perfect hindsight (Victorious horror story) the Centaurs look like a much better long-term bargain...
Could some of the six Illustrious be passed to a foreign navy ?
How could the Victorious silliness be strangled in the cradle ?
Long term effects ?

Gentlemen, start your engines !

Is the POD for this 15th August 1945?


"Le radar Blue Circle du Tornado F2, c'est du béton !" (French pilots to their RAF fellows, 1985)

Were the French pilots Michel Tanguy and Ernest Laverdure?

 

[NOMISYRRUC]

Ideally, scrap them as soon as possible to get the Irresistibles (Ark Royals) and Maltas into service, but there's probably not the money for that.

AIUI money was a problem, but more important was a lack of industrial capacity. This was the Austerity Era and priority had to be given first to the Export Drive, second rebuilding the country and modernising HM Forces was a distant third.

The powers thought that the UK could only afford to rearm once and all the available money was put into developing the best weapons that could be put into service for 1957, which was termed The Year of Maximum Danger because that was their estimate of when World War III was most likely to break out.

However, North Korea buggered it up by invading South Korea in 1950 which led to the 1951 Rearmament Programme.

 

[Archibald]

Glad to have you onboard !

 

[NOMISYRRUC]

...angled deck (tests on Triumph in 1952 but the idea had been around for a few years).

Do you know for how many years? I'm surprised that it wasn't though of earlier and have done timelines where Warrior conducted angled flight deck trials in 1948 instead of the rubber deck trials that took place in the real world.

 

[NOMISYRRUC]

Glad to have you onboard !

Merci beaucoup.

However, please will you confirm POD's date.

If the POD is 15th August 1945 I'd want to cancel Hermes, Lion, Tiger and Blake by February 1946 and keep the third Audacious.

 

[EwenS]

...angled deck (tests on Triumph in 1952 but the idea had been around for a few years).

Do you know for how many years? I'm surprised that it wasn't though of earlier and have done timelines where Warrior conducted angled flight deck trials in 1948 instead of the rubber deck trials that took place in the real world.

From Friedman’s British Carrier Aviation p303.
The angled deck was conceived at a Ministry of Aviation conference on means of using the new flexible deck on 7 August 1951. It was then seen that it could be extended to conventional aircraft.

 

[EwenS]

Glad to have you onboard !

Merci beaucoup.

However, please will you confirm POD's date.

If the POD is 15th August 1945 I'd want to cancel Hermes, Lion, Tiger and Blake by February 1946 and keep the third Audacious.

Work on Defence (later Lion), Tiger & Blake was suspended in 1946. The incomplete hulls were laid up while various redesign plans were worked through. Work didn’t restart until 1954/55 and Defence was renamed Lion in 1957.

The problem facing the RN in 1946 is that the cruiser is still seen as a necessary element of the fleet and most of the RN ships are either worn out or equipped with obsolete systems. The problem is that by the time they completed 1959-61 everything had changed.

 

[NOMISYRRUC]

Glad to have you onboard !

Merci beaucoup.

However, please will you confirm POD's date.

If the POD is 15th August 1945 I'd want to cancel Hermes, Lion, Tiger and Blake by February 1946 and keep the third Audacious.

Work on Defence (later Lion), Tiger & Blake was suspended in 1946. The incomplete hulls were laid up while various redesign plans were worked through. Work didn’t restart until 1954/55 and Defence was renamed Lion in 1957.

The problem facing the RN in 1946 is that the cruiser is still seen as a necessary element of the fleet and most of the RN ships are either worn out or equipped with obsolete systems. The problem is that by the time they completed 1959-61 everything had changed.

I'm aware of that.

 

[NOMISYRRUC]

...angled deck (tests on Triumph in 1952 but the idea had been around for a few years).

Do you know for how many years? I'm surprised that it wasn't though of earlier and have done timelines where Warrior conducted angled flight deck trials in 1948 instead of the rubber deck trials that took place in the real world.

From Friedman’s British Carrier Aviation p303.
The angled deck was conceived at a Ministry of Aviation conference on means of using the new flexible deck on 7 August 1951. It was then seen that it could be extended to conventional aircraft.

This is a website about the man who's credited with having the idea.

The Angled Deck

www.denniscambell.org.uk

It says that he had the "eureka moment" on 7th August 1951 too.

 

[EwenS]

To pick up on the Majestic/Colossus with Seamew and/or Type 191 aspect again. In the 1950s there were multiple carriers involved in various trials and training roles:

Dartmouth Training ship: Triumph replaced the cruiser Devonshire in 1953 but was retired in 1955 without replacement
Home Fleet Training Squadron: Two carriers, Implacable and Indefatigable from 1951 to 1955 when they were replaced by Ocean and Theseus (actually used as helicopter carriers during Musketeer)
Trials and Training Carrier: One carrier, Illustrious, then Bulwark and then Warrior with the role abolished in 1957

Carriers in the reserve fleet, (e.g. Indomitable, Implacable and Indefatigable from 1955) tended to be in class III status, de-stored and and at extended notice on the basis they had serious defects or required significant work to be useful. As such, class III was a sort graveyard status where ships deteriorated until they were sold for breaking.

The RNVR squadrons and their Seamews, Gannets, Attackers and Sea Hawks would, on mobilisation, have embarked on the three to four carriers active in the trials and training roles, until the RNVR was abolished and its squadrons disbanded in 1957.

Are these of any use?

View attachment 645811

Op-CV = Operational Fleet Carrier
Op-CVL = Operational Light Fleet Carrier
Op-BB = Operational Battleship.
AMS = Aircraft Maintenance Ship (i.e. Unicorn)
AR = Heavy Repair Ship (i.e. Triumph)

View attachment 645812
​

Triumph was replaced by the Dartmouth Training Squadron, which consisted of a destroyer and 2 frigates. That is, according to Leo Marriott in Royal Aircraft Carriers 1945-1990. The Dartmouth Training Squadron was a victim of the Mason Defence Review of 1974-75. It's role was assumed by the Dartmouth Training Ship which which was initially provided by rotating Fearless and Intrepid. Fife relieved them in the late 1980s, but she was sold to Chile and her place was taken by Bristol.

Couple of changes required to those Excel sheets.

Formidable was trooping until 3/2/47. She then had a short refit at Rosyth when she was cocooned for reserve.

Illustrious was in refit from the end of Jun 1945 to June 1946 after which she took up duties as the Home Fleet trials and training carrier, replacing Triumph.

 

[JohnR]

Displaying my ignorance again was is the meaning of POD?

 

[SSgtC]

Displaying my ignorance again was is the meaning of POD?

Point of Departure. Basically the point where the alternate world splits from ours

 

[Archibald]

Glad to have you onboard !

Merci beaucoup.

However, please will you confirm POD's date.

If the POD is 15th August 1945 I'd want to cancel Hermes, Lion, Tiger and Blake by February 1946 and keep the third Audacious.

Did not really thought about the exact POD date back then - but really: be my guest, I'm fine with your suggestions here.
the Tigers going away ?
the third Audacious saved ?
I'm all for it.

 

[NOMISYRRUC]

Glad to have you onboard !

Merci beaucoup.

However, please will you confirm POD's date.

If the POD is 15th August 1945 I'd want to cancel Hermes, Lion, Tiger and Blake by February 1946 and keep the third Audacious.

Did not really thought about the exact POD date back then - but really: be my guest, I'm fine with your suggestions here.
the Tigers going away ?
the third Audacious saved ?
I'm all for it.

I hadn't read the title of the thread properly. The POD's 1948 so it's not possible to save the third Audacious.

 

[Archibald]

Ah yes, sorry for that. 1948 then.

 

[Yellow Palace]

On the infrastructure side, anyone know when the RN stopped using lots of shoring to prop up ships in dry-dock?

Not until the 21st century - and sometimes even then. NOTTINGHAM was put on breast shores following her collision.

Breast shores are more adaptable to awkward hullforms, so were a virtual necessity for small craft and submarines for a long time. It's possible to use a shaped cradle, which is what's generally done today, but that requires fairly detailed knowledge of the underwater form of the ship that wasn't always readily available. You also have less of the hull obstructed by dock blocks, making access easier for maintenance.

As information sharing (and consistent shipbuilding!) has improved, the barriers to using wing blocks have reduced. Wing blocks (or docking cradles, which are effectively the same thing) are generally preferable because it's much harder for the ship to fall off them. During the docking evolution the ship loses hydrostatic stability as it lands on the blocks; breast shores can't go on until this point, which is when the risk of capsize is highest. And doing so requires putting people in the dock, between the unstable ship and a solid wall.

If the docking has been planned correctly, and nothing goes wrong, this is reasonably safe. But accidents can and do happen - Portsmouth dockyard stopped using breast shores in the 2000s after a commercial ship fell off the blocks whilst the shores were being put in. Fortunately nobody was seriously injured, but it was a close-run thing.

Breast shores are still a useful option for unusual dockings, and are still the preferred in some yards. When I did the RINA dry dock training course the final exam was to work out the docking arrangements for a ship that had a particularly inconvenient hullform - it would have been much easier with breast shores, but we were directed to use wing blocks.

 

[NOMISYRRUC]

So what we want is for the Colossus to be Majestics, the Majestics to be Centaurs and the Implacables to be Audacious.....with Y300 type machinery and A/C electrics all round.

If you mean:

• 10 Majestics and 10 Centaurs laid down instead of 10 Colossues, 6 Majestics and 4 Centaurs...

And then:

• 20 Centaurs laid down instead of 10 Majestics and 10 Centaurs...

Brilliant! 20 aircraft carriers capable of operating 30,000lb aircraft instead of only four, plus six rated at 20,000lbs and ten rated at 15,000lbs. That would have made life a lot simpler for the Royal Navy at the expense of the ships greater manpower costs due to the Centaur class having more powerful machinery that the Colossus and Majestic classes.

It would also be a boon for the other navies that were operating Colossus and Majestic class aircraft carriers IOTL. For example the TTL HMAS Sydney would have been capable of operating Sea Venoms and Gannets.

Unfortunately, the POD for that is at least 6 years before the POD in the OP. Plus, the extra material and labour wouldn't be available to build the larger hull wouldn't be available. I doubt that the more powerful machinery could have been built either. However, those problems could be solved by not building the Swiftsure and Tiger class cruisers. There's also the strong possibility that Albion, Bulwark, Centaur and Hermes would be cancelled at the end of the war in favour of completing Hercules, Leviathan, Majestic and Powerful in the second half of the 1940s.

Making the Implacables Audaciouses is another brilliant idea. Unfortunately, that can't be done because the Second London Naval Treaty was in force and that limited the maximum size of an aircraft carrier to 23,000 tons. It aught to be possible to have another Audacious built in place of Vanguard. However, that can't be done because it's at least 7 years before the POD.

However, it was the British that had the maximum size of an aircraft carrier which was set at 27,000 tons by the Washington Naval Treaty reduced to 23,000 tons under the Second London Naval Treaty. Had that limit remained at 27,000 tons the six armoured carriers would have been better ships as built and it would have been easier to modernise them.

It would have been possible to build the six ships with hulls that had the same dimensions as the rebuilt Victorious.

Furthermore, the OTL Formidable, Illustrious, Indomitable and Victorious could have had hangars with clearances of 17 feet 6 inches instead of the OTL 16 feet. (I'm assuming that the TTL Indomitable doesn't have the half-hangar of OTL.)

Had the OTL rebuild of Victorious still happened that would have avoided the need to strip the hull down to the flight deck, cut what was left in half, insert a new centre section and rebuild the hull back up to hangar deck level. Furthermore, there might have been no need to fit bulges. They would still have had to make the structural adjustments required for the steam catapults and angled flight deck, the new superstructure would still have been fitted and there would still have been the decision to fit new boilers when work was well advanced. However, a lot of time and money would have been saved.

Implacable and Indefatigable were laid down in 1939, suspended during the invasion crisis, launched in December 1942 and completed in 1944. The extra displacement would allow them to have two full-length hangars with higher clearances than the 14 feet of OTL, but not 17 feet 6 inches. Therefore, an extensive rebuilding of the hull along the lines of Victorious would still have been required if it wasn't possible to convert the two existing hangars into a single hangar. On the other hand, had the requirement to operate 30,000lb aircraft been introduced in 1941 or even better 1940 it might have been possible to alter the design and increase their hangar clearances to 17feet 6 inches.

However, the Second London Naval Conference was 12 years before the POD.

Making the change from DC to AC in the second half of the 1930s instead of the 1950s in all British warships combined with the earlier introduction of higher-pressure machinery would have helped a lot too. However, that's a decade or more before the POD.

 

[NOMISYRRUC]

The Seamew is odd. That it was to be operated from escort carriers is often used as a throwaway remark but suffers from the flaw that there were no escort carriers (aside from Campania). More likely, it was intended that the RNVR squadrons equipped with it would be mobilised to operate from the trials and training carrier and the various ships in reserve (e.g. Illustrious in 1955/56).

Although only one escort carrier was in existence there might have been plans to convert suitable merchant ships in wartime.

And yes as I understand it the plan was to employ the light fleet carriers (including the Centaurs) in the trade protection role or in other words they would be used as "escort carriers" in wartime.

This is a paragraph from Page 301 from my copy of Norman Friedman's British Carrier Aviation.

The modernisation numbers were set by the capacity of the Royal Dockyards and by the requirement that the fleet should be modernised by 1957: by mid-1948 the plan was to modernise three fleet carriers and three rather than six Colossus class ships. The final pre-Korean War plan, the "revised restricted fleet", of May 1949, showed a seventh modernisation, a fleet carrier converted to a trials and deck-landing training ship. Although it was already understood that the 1942 light fleet carriers could never operate the new heavy aircraft, they were still valued as trade-protection or fighter carriers.

The paragraph has this footnote.

They were essential because it seemed unlikely that converted merchant ships (CVEs and MACs) could support modern ASW aircraft and trade-protection fighters. In 1946 the Naval Staff estimated that, eighteen months into a war, the Royal Navy would require twenty carriers beyond its existing building programme (12 escort carriers, four replenishment carriers and three training carriers, plus one spare). Unfortunately, the most suitable merchant ships (18-knot) liners, would be needed for other purposes. This left 14-knot merchant ships, and in 1946 the staff could not except to requisition fifteen of them in wartime. The first British postwar plan, produced in 1947 as a run-up to the Nine Year Plan, called for 12 light fleet carriers for trade protection (including some for hunting groups), plus four to replenish battle force carriers, four for training and five for spares. This was in addition to eight fleet carriers (the two Ark Royals and six existing ships, modernised). Against this requirement, the Royal Navy had four Hermes class under construction, and six Colossus in service, the Commonwealth fleets would contribute their two, plus two more for a total of fourteen. The proposed 1956-57 fleet included six new light fleet carriers (construction to begin in 1949) and eleven modernised ones (four Hermes, six Colossus and HMS Majestic, as then unsold). Given economic realities, this programme had little chance of success, it was apparently the Board's opening move in the defence debate. One possibility raised at this time was to extend the deadline for modernisation to 1960. By May 1949 the projected 1957 wartime fleet was reduced to five fleet carriers (two Ark Royals and three modernised ships), plus one for deck training, four Hermes and two older light fleet carriers in reserve Category C (to maintain the pre-Hermes total of six light fleet carriers). At this time the Admiralty was forced to admit that henceforth the Royal Navy alone would be unable to protect British maritime communications without US military participation; the 1947 study had assumed that, as in 1941, the Untied States might assist Britain short of war. The 1947 and 1949 figures are from E.J. Grove, Vanguard to Trident (US Naval Institute, Annapolis, 1987). Se also my Postwar Naval Revolution.

 

[NOMISYRRUC]

Ah yes, sorry for that. 1948 then.

In that case the correct course of action would have been to abandon the planned modernisations in 1948. As we know and they aught to have known at the time the alterations required would take so long and been so extensive that they were better off building new ships.

Steel is cheap and the new equipment fitted to Victorious such as the steam catapults, new lifts, new armament, new electronics, new boilers and new electrical system would cost the same if installed in a new ship of the same size.

Except that it wouldn't be the same size. They'd begin to design the OTL1952 Carrier sooner or a 35,000 ton ship.

 

[zen]

Dial this back.
Make Ark Royal the 29,000ton design.
Then RN won't accept a reduction to 23,000tons. But the 27,000tons figure would remain instead.
And yes, the 29,000ton design can, through careful accounting, be made to look like 27,000tons.

https://www.secretprojects.co.uk/threads/rn-ah-new-carrier-1920s.34045/

 

[PMN1]

Making the Implacables Audaciouses is another brilliant idea. Unfortunately, that can't be done because the Second London Naval Treaty was in force and that limited the maximum size of an aircraft carrier to 23,000 tons. It aught to be possible to have another Audacious built in place of Vanguard. However, that can't be done because it's at least 7 years before the POD.

By this time the Treaty is as healthy as the Monty Python Parrot.

 

[NOMISYRRUC]

Work on Defence (later Lion), Tiger & Blake was suspended in 1946. The incomplete hulls were laid up while various redesign plans were worked through. Work didn’t restart until 1954/55 and Defence was renamed Lion in 1957.

The problem facing the RN in 1946 is that the cruiser is still seen as a necessary element of the fleet and most of the RN ships are either worn out or equipped with obsolete systems. The problem is that by the time they completed 1959-61 everything had changed.

I'm aware of that.

I'm also aware that they were restarted because it was thought that they were resumed because it was assumed that they would be completed sooner and cheaper than new ships with the same armament. However, the assumptions were wrong.

As the PODs 1948 I'd like the Admiralty to decide that the ships weren't worth completing in 1948. The intention would be to build new cruisers in the 1950s. However, when the time to order the ships came it was decided that it would be better to concentrate the resources on new aircraft carriers instead of a mix of new aircraft carriers and new cruisers.

 

[NOMISYRRUC]

Making the Implacables Audaciouses is another brilliant idea. Unfortunately, that can't be done because the Second London Naval Treaty was in force and that limited the maximum size of an aircraft carrier to 23,000 tons.

By this time the Treaty is as healthy as the Monty Python Parrot.

The Treaty did not cease to be until 3rd September 1939.

It was very much alive on 21st February 1939 which was when Implacable was laid down. Indefatigable wasn't laid down until 3rd November 1939, but it was ordered before the war broke out.

In any case the POD's 1948.

 

[Volkodav]

Tempted to say nothing because in my twisted alternative reality both were commissioned into the RAN not the RN, crews were Australian and air groups predominantly Kiwi. Post war both were transferred outright to the RAN, along with all remaining stocks of Hellcats and Avengers in Australia, to offset the massive support and supply accounts accrued to Australia in the later years of the war by both the US and UK.

As RAN vessels they would have been perfectly adequate until the mid 50s when upgrade options could have been considered. Thinking interim angled deck and FJ Furies, with the lower hangar completely converted for accommodation, stores and workshops. A more extensive upgrade later with a full angled deck steam cats etc. would see them out until the 70s operating enhanced tigers, i.e. putting as radar in the long nose specified to carry a radar that was never fitted. Maybe, just maybe Super Tigers from the mid 60s. ASW and AEW types would have had to be deck stowage and maintenance only, not convenient but doable.

 

[NOMISYRRUC]

According to my copy of Friedman the waterline length of the 1952 Carrier was 870 feet, but that the overall length was 815 feet.
Brown in Rebuilding the Royal Navy says that the length was 815 feet, but not whether it was the overall length or the length at the waterline. My guess that this is a printing error and that it should be 815 feet at the waterline and 870 feet overall.