The Centaur carrier fleet - a better fate...

[bobtdwarf]

Yes but... wasn't the Centaur machinery only 76 000 hp, much less than the 100 000 ++ of the other carriers ? and the speed lower, 27 kt or less ? if the ships are lenghtened, the additional weight will make them even slower.

it would improve the length/beam ratio which will offset that a LOT on top speed... sure she will accelerate like a pig but once you get her going...

 

[CV12Hornet]

The more info posted, including those hangar freeboard numbers, the more interesting a lengthened and properly designed angled deck Centaur Class becomes.
I think the exorbitant cost of the Victorious rebuild would have been better directed toward the 4 Centaur vessels.

Isn't that just one of the mid-50s medium carrier proposals?

Honestly, those are a far better idea than all these Centaur rebuilds being proposed. There's only so far you can push an existing design, especially one built as a WW2 economy ship.

 

[bobtdwarf]

Isn't that just one of the mid-50s medium carrier proposals?

Honestly, those are a far better idea than all these Centaur rebuilds being proposed. There's only so far you can push an existing design, especially one built as a WW2 economy ship.

Yeah that is a lot like the 35k ton one.. imagine having a pair of Audacious class and a pair of the '54 35,000 ton new builds in the 60's

 

[CV12Hornet]

Yeah that is a lot like the 35k ton one.. imagine having a pair of Audacious class and a pair of the '54 35,000 ton new builds in the 60's

You'd have to limit the scope creep in Victorious' rebuild and kill the redesign of Hermes for two. The first is doable. The second is harder, especially if you want to avoid a major gap in the RN's fleet structure while Eagle is in rebuild 1959-1964.

 

[Rule of cool]

Moving lifts to accommodate the machinery for longer catapults and the other suggestions is very cool, however I keep wondering about the cost. Granted an aircraft carrier is a national strategic asset and it is quite acceptable to my 'Procurement' brain to treat it differently to other ships, indeed it is an entire capability in itself like a submarine arm or long range strike capability. That said there has to be a point where cutting a Centaur in half to lengthen it in order to get another ~15 service isn't as good as building CVA01 or a Clemenceau as using that for 30+ years.

 

[bobtdwarf]

You'd have to limit the scope creep in Victorious' rebuild and kill the redesign of Hermes for two. The first is doable. The second is harder, especially if you want to avoid a major gap in the RN's fleet structure while Eagle is in rebuild 1959-1964.

figure replace Hermes with the first of the '54s and also do the historic Centaur steam cat fit... if they come out at the same time you are good, but it wouldn't be a horrible thing to have Eagles rebuild between 60-65 and put the water-cooled JBLs in during.

 

[CV12Hornet]

figure replace Hermes with the first of the '54s and also do the historic Centaur steam cat fit... if they come out at the same time you are good, but it wouldn't be a horrible thing to have Eagles rebuild between 60-65 and put the water-cooled JBLs in during.

The problem is, for all of Hermes' faults she can be made ready a good three years before one of the '54 carriers. And if you're screwing Victorious, as you need to to keep any of these carriers going past 1957, then remember that she's also an axial-deck hydraulic-cat carrier.

You'd basically be leaving the RN with all of one carrier, Ark Royal, in satisfactory fit until the first of the '54 carriers is ready and I doubt it'd be easy to convince anyone involved of that.

One medium carrier is straightforward. Two, as I hope I've made clear, requires a lot of hoops to jump through.

 

[SSgtC]

Off the wall idea. Could the RN convince the USN to help cover the gap by one or two Essex class deployments? It's not a perfect solution, but it might help them cover the gap in their own carrier forces until the first of the UK's new carriers commissions

 

[CV12Hornet]

Afraid not. The US was short of deployable carriers themselves in this period. Six modernized Essexes had been converted to ASW carriers; Coral Sea and Oriskany were in deep refit; and that left a total of 14 carriers (eight Essex, two Midway, four Forrestal) out of the fifteen needed - and Independence was still working up in 1959 and would not deploy until August 1960. The situation would only modestly improve into the early 1960s as new ships were commissioned but more Essexes were pulled out of attack carrier duties.

 

[SSgtC]

So, in line with that, what about Lake Champlain? She had received the SCB-27A overhaul, and was about to be decommissioned in 59 to receive the same SCB-125A refit that Oriskany was getting (it was later canceled and she was placed in reserve instead). It would be a scratch team, and it wouldn't be a very modern air group (FJ-4s, Panthers and Banshees, most likely), but that would still be equal to or better than anything the UK was deploying at that time. The only down side is that she's still an axial deck carrier. But in this case, beggars can't be choosers.

 

[CV12Hornet]

So, in line with that, what about Lake Champlain? She had received the SCB-27A overhaul, and was about to be decommissioned in 59 to receive the same SCB-125A refit that Oriskany was getting (it was later canceled and she was placed in reserve instead). It would be a scratch team, and it wouldn't be a very modern air group (FJ-4s, Panthers and Banshees, most likely), but that would still be equal to or better than anything the UK was deploying at that time. The only down side is that she's still an axial deck carrier. But in this case, beggars can't be choosers.

Well, that gets into the question of whether the US is willing to delay that refit and pay the money to deploy her to Britain, in service of British interests - does the US want to be seen enabling the Brits to bully Kuwait or suppress mutinies in East Africa, the carrier things the Brits did in the early 60s? Especially so soon after Suez and with Vietnam ramping up?

On balance I'd say no, and the US would much prefer to force the British to keep up NATO strike carrier commitments rather than send carriers gallivanting off on colonial adventures.

 

[SSgtC]

On balance I'd say no, and the US would much prefer to force the British to keep up NATO strike carrier commitments rather than send carriers gallivanting off on colonial adventures.

This was what I had rattling around my skull. That the USN would backfill the British carrier commitment to Strike Fleet Atlantic with an Essex like Lake Champlain (which really wasn't doing much at the time), while the Brits can use their own decks for colonial policing until the first new Brit carrier joins the fleet. At that point, which shouldn't be later than 59/60, Lake Champlain can be either be brought into the yard for her own overhaul, or be decommissioned as IOTL and placed in reserve.

 

[Rule of cool]

does the US want to be seen enabling the Brits to bully Kuwait or suppress mutinies in East Africa, the carrier things the Brits did in the early 60s?

colonial policing

I've recently read, in conjunction with the British in Vietnam thread, that prior to Vietnam the US were conflicted about Britain's world role. As an anti-colonial power they didn't want to support any British colonial efforts, however they also wanted to contain global communism and for example in 1961 Iraq was a Soviet client that was threatening Kuwait.

That said, with regards to this thread and tying knots with Centaur class carriers, there is a simple answer; provide the means to discharge the obligations, ie don't wait until 1965 to order a new carrier. Most of Britain's problems arise from trying to do things on the cheap, penny wise and pound foolish.

 

[bobtdwarf]

The problem is, for all of Hermes' faults she can be made ready a good three years before one of the '54 carriers. And if you're screwing Victorious, as you need to to keep any of these carriers going past 1957, then remember that she's also an axial-deck hydraulic-cat carrier.

You'd basically be leaving the RN with all of one carrier, Ark Royal, in satisfactory fit until the first of the '54 carriers is ready and I doubt it'd be easy to convince anyone involved of that.

One medium carrier is straightforward. Two, as I hope I've made clear, requires a lot of hoops to jump through.

I was more making an aside musing then a serious proposal... just musing on what it would be like to have that 2+2 combo.

70s and very early 80s would be a wild time on the second hand carrier market

 

[GK Dundas]

Indeed. Here’s my lengthened Centaur in the 80s with 25x F/A-18s.

I added a long waist catapult (199ft BS5 as on Eagle/Ark Royal) for higher take off weights and a Hermes-like angle deck with a ~6.75 degree angle (wasn’t sure a large Victorious like sponson could be made to work on such a narrow hull)View attachment 744378

Drop about seven of those Hornets and you might be able to cram in about 4 E 1 Tracers and perhaps one or two more SeaThings .
. That's a pretty potent light carrier you've got there !

 

[uk 75]

The elephants in the room are not the carriers but the aircraft they carry.
At the beginning of the 1960s the RN had four carriers able to carry its frontline jets (Sea Vixens, Scimitars and Buccaneers). Centaur could carry the first two.
Recognising that it needed a heavier strike/fighter like the F4 it proposed to convert Eagle and build two new carriers (CVA01).
France meanwhile was actually bringing into service two brand new design carriers (Foch and Clemenceau) for which it had its own strike fighter (Etendard) and a US intereceptor (F8).
As a result of its over ambition with F4 and CVA01 the RN lost its fixed wing carriers by 1980 while France operated its until well after the end of the Cold War.
Ark Royal, Eagle, Hermes and Victorious could have operated well into the 80s with Buccaneers and a realistic Sea Vixen replacement (Twosader or AFVG for example). A much less complex and sensible pair of Eagle sized carriers could have secured the force into the 90s if they had been built in the late 60s early 70s.
Equipped with F18s they could have seen in the CTOL CVFs ordered in 1997.

 

[CV12Hornet]

This was what I had rattling around my skull. That the USN would backfill the British carrier commitment to Strike Fleet Atlantic with an Essex like Lake Champlain (which really wasn't doing much at the time), while the Brits can use their own decks for colonial policing until the first new Brit carrier joins the fleet. At that point, which shouldn't be later than 59/60, Lake Champlain can be either be brought into the yard for her own overhaul, or be decommissioned as IOTL and placed in reserve.

It's unlikely a 1954 CV would be joining the fleet in 1960. At the time the Brits expected to commission the first in 1962 and it would be 1963 before they could deploy her.

Ark Royal, Eagle, Hermes and Victorious could have operated well into the 80s with Buccaneers and a realistic Sea Vixen replacement (Twosader or AFVG for example).

They could not. Victorious' age and Ark Royal's various mechanical ailments ensure that. Eagle is in better shape but even she can't be pushed very far into the 80s; recall the refit schedules involved in operating steam boilers from other threads.

There's a reason the RN believed only Hermes was viable past 1975.

 

[Rule of cool]

The elephants in the room are not the carriers but the aircraft they carry.
At the beginning of the 1960s the RN had four carriers able to carry its frontline jets (Sea Vixens, Scimitars and Buccaneers). Centaur could carry the first two.
Recognising that it needed a heavier strike/fighter like the F4 it proposed to convert Eagle and build two new carriers (CVA01).
France meanwhile was actually bringing into service two brand new design carriers (Foch and Clemenceau) for which it had its own strike fighter (Etendard) and a US intereceptor (F8).
As a result of its over ambition with F4 and CVA01 the RN lost its fixed wing carriers by 1980 while France operated its until well after the end of the Cold War.
Ark Royal, Eagle, Hermes and Victorious could have operated well into the 80s with Buccaneers and a realistic Sea Vixen replacement (Twosader or AFVG for example). A much less complex and sensible pair of Eagle sized carriers could have secured the force into the 90s if they had been built in the late 60s early 70s.
Equipped with F18s they could have seen in the CTOL CVFs ordered in 1997.

Aircraft are the 'problem', especially given the RN's fighter requirement is far too small to make it worthwhile for the British to develop their own, This is why the RN bought the Spey Phantom and the French bought the Crusader. In the early 60s the USN future fighter options were the F111B and VFAX, then these merged into the VFX-F14 in 1968 and the USN had no plans for a 2nd tier fighter suitable for smaller carriers into the 2nd iteration of the VFAX-F/A 18 in 1974.

Once Britain buys the Spey Phantom to meet it's requirement to have a fighter by 1968 the RN is out of the fighter buying game for 15 years. Carriers will have to be bought around these Buccaneer and Phantom fleets, and these aircraft will have to be replaced to suit a carrier built for them and so on in a synergistic relationship.

 

[H_K]

Isn't that just one of the mid-50s medium carrier proposals?

Honestly, those are a far better idea than all these Centaur rebuilds being proposed.

My idea is to reuse the Centaurs’ propulsion and hull blocks while still building. So very different from an expensive Victorious-style rebuild or a completely new-build fleet carrier.

Jumboizing a hull by cutting it open and inserting a prebuilt segment is a well known and manageable process, and the extra cost should mostly be just steel. Might have been doable say around 1946-49 (obviously the more you wait the more it becomes a rebuild)… if done early enough it would not represent much more work than what went into Hermes.

 

[bobtdwarf]

My idea is to reuse the Centaurs’ propulsion and hull blocks while still building. So very different from an expensive Victorious-style rebuild or a completely new-build fleet carrier.

Jumboizing a hull by cutting it open and inserting a prebuilt segment is a well known and manageable process, and the extra cost should mostly be just steel. Might have been doable say around 1946-49 (obviously the more you wait the more it becomes a rebuild)… if done early enough it would not represent much more work than what went into Hermes.

might want to take a look at putting the plug forward of the island... don't have to run longer prop shafts but gain more distance for cats.

I wonder if a hangar edge lift would work? Not a deck edge, but one canted over far enough to not obstruct the hangar but still within the hull (even if bump to the sponson is required). Would keep it safe from waves while not sucking up space in the garage.

 

[BlackBat242]

So, in line with that, what about Lake Champlain? She had received the SCB-27A overhaul, and was about to be decommissioned in 59 to receive the same SCB-125A refit that Oriskany was getting (it was later canceled and she was placed in reserve instead). It would be a scratch team, and it wouldn't be a very modern air group (FJ-4s, Panthers and Banshees, most likely), but that would still be equal to or better than anything the UK was deploying at that time. The only down side is that she's still an axial deck carrier. But in this case, beggars can't be choosers.

The OTHER down-side is that the SCB-27A modernization only exchanged the H4B hydraulic catapults for H-8 hydraulic catapults - to get the steam catapults you need the SCB-27C upgrade. In addition, SCB-27A kept the existing arresting gear and did NOT move the aft aircraft lift to deck-edge, while SCB-27C included stronger arresting gear and moved the aft lift to deck-edge.

So yes - a really limited capability.
H4B: 18,000 lbs to 90 mph in 96 ft
H8: 15,000 lb to 120 mph or 62,500 lbs to 70 mph in 190 ft
C-11-1: 45,000lb to 132kt or 70,000lb to 108kt in 240 ft

And there is the inconvenient reality that Champ was fully occupied from her return from Korea at the end of 1953 with Med cruises & NATO exercises (still rated as CVA) until July 1957, and from August 1957 (as CVS) in ASW ops, training, disaster relief, Cuban blockade, and Mercury & Gemini capsule recovery operations until she actually decommissioned in 1966.

USS Lake Champlain (CV 39)

1964 was a particularly trying year - she must have been getting tired:

January 10, 1964: Virginia Capes area: USS LAKE CHAMPLAIN loses 41 feet of its catwalk in a storm.

May 6, 1964: 150 miles east of Cape Henry, Va.: USS LAKE CHAMPLAIN and USS DECATUR (DD 936) collide in the Atlantic. The DECATUR sustains heavy damage to its superstructure, but there are no personnel injuries.

June 3, 1964: Chesapeake Bay, Va.: USS LAKE CHAMPLAIN collides with the Norwegian freighter SKAUVAAG. There are no injuries.

 

[BlackBat242]

I wonder if a hangar edge lift would work? Not a deck edge, but one canted over far enough to not obstruct the hangar but still within the hull (even if bump to the sponson is required). Would keep it safe from waves while not sucking up space in the garage.

Like the early design for the Indian Vikrant 2?








Even as completed her aircraft lifts could still be enclosed without much trouble:

 

[bobtdwarf]

Like the early design for the Indian Vikrant 2?



View attachment 744889

View attachment 744890


Even as completed her aircraft lifts could still be enclosed without much trouble:

View attachment 744891

View attachment 744892

So I was not totally out of my screaming tree?

Excellent! I had no idea that anyone had actually done it.

 

[GK Dundas]

Drop about seven of those Hornets and you might be able to cram in about 4 E 1 Tracers and perhaps one or two more SeaThings .
. That's a pretty potent light carrier you've got there !

In this thread and others concerning light carriers I be been talking about my ideal carrier for the Canadian Navy. I think I may have found something close to it.
I wonder if you could squeeze a larger engines in her . And how much horsepower you could put in a carrier built say somewhere between 1964 and 1968.
I

 

[H_K]

Drop about seven of those Hornets and you might be able to cram in about 4 E 1 Tracers and perhaps one or two more SeaThings .

Personally I'm going with Spey Twosaders with pulse doppler radar for look down/shoot down interceptions... from the late 60s onwards. Would Canada want a few?

 

[PFJN]

My idea is to reuse the Centaurs’ propulsion and hull blocks while still building. So very different from an expensive Victorious-style rebuild or a completely new-build fleet carrier.

Jumboizing a hull by cutting it open and inserting a prebuilt segment is a well known and manageable process, and the extra cost should mostly be just steel. Might have been doable say around 1946-49 (obviously the more you wait the more it becomes a rebuild)… if done early enough it would not represent much more work than what went into Hermes.

Hi,
In reality there would likely be a fair bit of difference between building a purpose built longer version of any ship (as I assumed was being proposed in earlier posts), than jomboizing an existing design by cutting it open and inserted a new segment as you appear to be proposing in the quote above.

Specifically, if you intend to "add a plug" to an existing design, that plug really needs to be at (or very near) where the hullform is at its widest (typically midships) so as to not negatively impact flow along the hull and into the propellers, as opposed to fore or aft of midships, like shown in previous posts.

In addition, while not really a show stopper or anything, adding a plug anywhere on a ship is likely to end up being a bit more than just steel, because there will need to be ventilation, lighting, paint, and other items in that new section (especially if part of it will be used as hangar space) and pipes, cabling, and ventilation etc will have to likely be run through it to connect some of the systems in the aft the ship to those forward of the cut (or if the cut separates the boiler rooms from the motor rooms etc).

And finally, fora ship one of the main loads it gets designed to is its hull girder bending moment, which is ususally a function of the length of the vessel. Here the maximum bending moment that the hull girder will be expected to see is approximated assuming that the hull is balanced either with its bow and stern on the crest of a wave that it about the same length of the ship, or with the ship balanced on a wave with its bow and stern in the troughs of a wave about the same length as the ship. As ship, if a shipis made longer its design bending moment will go upand it may end up needing to have some additional structure added to increase its "section modulus" to resist those increased bending moments.

As noted above, none of these are necessarily "show stopper" type issues but they do contribute to making the addition of a "plug"to a design being a bit more than just adding steel.

 

[H_K]

Specifically, if you intend to "add a plug" to an existing design, that plug really needs to be at (or very near) where the hullform is at its widest (typically midships) so as to not negatively impact flow along the hull and into the propellers, as opposed to fore or aft of midships, like shown in previous posts.

Yes looking at Centaur's plans and hull lines I've come to the conclusion that the best location for a hull plug would be right below the island, at the bulkhead behind the forward machinery room.

This would allow 2 new hull sections to be inserted amidships, where the hull cross section is constant. These 2 sections would be duplicates of the forward turbine space and fwd boiler rooms, allowing the old forward machinery spaces just ahead of this to be freed up and converted to fuel & weapons storage.

See dashed red line below. Obviously this would best be done early during construction, before the machinery spaces and island have been installed.

If the plug had to be done after the hull is essentially complete, then it would best go where the dashed blue line is, i.e. ahead of the existing machinery spaces. But the hull cross section wouldn't be constant and that might be problematic.

 

[H_K]

P.S. The rationale for such a hull plug would be if the RN determined that rebuilding the wartime Illustrious class would not be economic and that the Centaurs's 725ft flight deck was just a little too short to effectively handle the longer deck runs associated with jets.

Ideal timing would be around 1946/47. This is when plans for heavier jet fighters started to appear and it became obvious that longer axial decks were needed (the angled deck hadn't been invented yet - that would wait until 1952). Across the pond the USN decided to embark on the first SCB-27 modernisations (Oriskany) with long H-8 catapults (200ft) and Mk 5 arrestor wires (155 or 200ft runout) - luckily for them the Essex class were big and their 850ft flight deck could fit the longer cats and wires.

For the RN, HMS Eagle was the only carrier in advanced stages of build that was long enough to fully operate the next generation of jets. So they might decide that lengthening the Centaurs while still in dock with a ~800ft axial flight deck (+80ft plug) would be the closest they could get to a "mini Essex" able to operate jets.

 

[Rule of cool]

All of this dances around the fact that the RN needed bigger carriers going forward, and Centaurs aren't the best available path for that. Likely the best path would be the Audacious class and the 1952-53 carrier design, failing that stretching the armoured carriers to get the best out of their 3 and 4 shaft power-plants along with the Audacious class. Trying to squeeze a wartime light carrier into the big strike carrier role will always be difficult, too difficult I'd say leading to sub-optimal results, although the RN has to play the financial, political and material cards it's dealt.

 

[bobtdwarf]

Yes looking at Centaur's plans and hull lines I've come to the conclusion that the best location for a hull plug would be right below the island, at the bulkhead behind the forward machinery room.

This would allow 2 new hull sections to be inserted amidships, where the hull cross section is constant. These 2 sections would be duplicates of the forward turbine space and fwd boiler rooms, allowing the old forward machinery spaces just ahead of this to be freed up and converted to fuel & weapons storage.

See dashed red line below. Obviously this would best be done early during construction, before the machinery spaces and island have been installed.

If the plug had to be done after the hull is essentially complete, then it would best go where the dashed blue line is, i.e. ahead of the existing machinery spaces. But the hull cross section wouldn't be constant and that might be problematic.View attachment 744987

the last "flat and fat" part of the mid hull as far forward as you can go before it starts to curve... cut it at the forward most point so you don't have to muck about with the exhaust piping... yup that IS the ticket

 

[PFJN]

...

View attachment 744987

Hi,
Too bad there aren't any resonably priced Centaur class kits available(other than maybe the resin waterline HMS Hermes) because this could have been an interesting what-if build