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Krakatoa
Post subject: Re: Republic of Algarve.Posted: October 12th, 2016, 8:08 am
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Don't forget the industrial might of the US was also putting together 27 Essex class at the same time. That's over 800,000 tons of carriers. Those numbers were built because? That would be Roosevelt's order not to change existing classes? Would the US Navy have liked to exchanged half of the Essex class for an extra 8-10 Midways - say a total of 12 Midways. I know I would. That would really have taken the heat off the US Navy for some considerable time.

I have hummed and ahhed about when to have the Dias building dates. 1939-to late 43, about 4 1/2 years (equivalent to 6 years in peace time work rates) sounded about right.

If I had built four 35 to 40,000 ton carriers, nobody would have said a word. But pushing the boundaries a bit with a huge carrier and I get jumped on. One of the reasons to use Algarve to build something like the Dias is that it is in an out of the way and could take the time to build something that size. "Industrial might" does not really come into it. As long as Algarve has the ability and resources to throw 240,000 tons at the 3 carriers. The biggest problem I forsee for them is keeping them manned and at sea with enough accompanying escorts. One fleet would have the Indian Ocean, the other would be responsible for the South Atlantic. The third ship would be in dock going through refurbishment. I certainly can not see them being replaced in the future (70's to 80's), as the technology expenses might be beyond Algarves budget. The only way they might keep a largish carrier(s) at sea is if the UK/US gave them the technology. I know the US would like some of its Allies to help with policing the seas.


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Garlicdesign
Post subject: Re: Republic of Algarve.Posted: October 12th, 2016, 8:13 am
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Hi everyone

To be fair to Krakatoa (it hurts somewhat, but I try), he has not provided any numbers on population and economy for Algarve so far, so there should be no problem pumping that country up to a size consistent with the Navy he has drawn, including his latest monstrosity. 30 - 35 million inhabitants and an industrial base the size of France's should suffice for a country with ample access to natural resources and no need to build any significant army (Thiaria in 1918 is a fully developed industrial country of 23 million, operating a maximum of eight dreadnoughts against Algarve's eleven plus two small ones if my count is right; during the second world war, Thiaria averages 28 - 29 million and builds a total of twelve capital ships (battleships, battlecruisers and fleet carriers); so far, Krakatoa has given Algarve eleven, although all of them a lot bigger). AU is subject to constant change, and increasing the total bio-mass of humanity beyond its historical limit is typical for most AUs.

Also to be fair, that last carrier strikes me as having originated from the same mindset that produced the H44. Apart from the questionable wisdom of creating a ship twice the size (and probably three times the cost) of the FDR with only 15% more airplanes (156 vs 130) - after all, the planes are not only offensively, but also defensively the prime armament of a carrier - the idea of going so big IMHO is only plausible if Algarve is some kind of dictatorship whose beloved supreme leader wants to show everyone that he produces more testosterone than anyone else. Which by the way would be a nice twist for this AU, perfectly justify the name 'James T. Kirk' and salvage the entire concept of this carrier to some extent (I prefer good comedy to mediocre drama). After all, Stalin also was on the right side in WWII, and he would certainly have liked that one.

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GD


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Krakatoa
Post subject: Re: Republic of Algarve.Posted: October 12th, 2016, 9:18 am
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Thank you GD for your input.

The nearest I have come to noting Algarves statistics is that the western half is mountainous and containing lots of Iron and coal and some other industrial ingredients. The population I figured to be around 30 million at 1914, down to 27 million at 1920 (war and Spanish Flu), up to 35 million by 1939. I worked that as being about half the population of France and Spain at similar times. Leaves plenty of growth room.

I like to use AU's to push the boundaries of building ship types. A huge carrier is not out of order, just not been offered all that often. Pleas remember GD that I am talking about internally carried aircraft, not deck parks. So it is closer to 156 to 100 if that. That is also carrying the much bigger aircraft types I have shown the Dias as carrying, which would really be a 1945 aircraft load.

I always like to have an element of comic relief. In the last AU I had Admiral Schwarzeneger slugging it out with the Japanese. In this AU Admiral James T. Kirk will have a tremendous fight somewhere at the start of ww2 that will immortalise him in Algarvian history. (I am still wondering how to get him aboard the bridge of the Enterprise with both the US and UK having ships of that name)


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Colosseum
Post subject: Re: Republic of Algarve.Posted: October 12th, 2016, 3:40 pm
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It's just unbelievable is all. You can try to quantify it with population figures etc but I still won't buy it. It just doesn't make sense given what we know about history.

I would be much more interested in seeing, say, a hydrographic survey ship and an oceangoing tug for this AU rather than the supercarriers. But then again, it IS an AU and as such is basically here just to have fun. So it should be something fun!

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acelanceloet
Post subject: Re: Republic of Algarve.Posted: October 12th, 2016, 5:57 pm
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I am going to ignore all the probabilities of this ship being build or designed in real life or in your AU, and focus on the technical difficulties. And, I am affraid, there are quite a few.
The first proposed aircraft carrier of this type was the CVA-58 United States. The size of this ship was made possible by the use of the flight deck as the strength deck. For the people who have no idea what that means: a lot of the stength against the ship bending is given by the height of the hull (the so called depth) from keel to strength deck. The cross section of this area is what gives the ship its overall strength, everything on top of that has to be fitted with expansion joints (these are slots where the ship has space to loosen or tighten when the rest of the ship is bending), otherwise these parts would be compressed or pulled on when the ship moves trough the waves. this was the reason for the split superstructure on the malta class, and these joints are visible across the flight deck of the midway class. everything below the main deck level has to be reinforced to have the same strength as the hull, and differences in the cross section have to be avoided (note the high hulls of ocean liners, the offset deck edge elevators on the united states and forrestal and the rounded sides of the elevator openings on the forrestals.

Back to this carrier. with its heavy armoured main deck (clearly definable as the hull main deck. deep under the 'hangar superstructure', long superstructure, huge elevator openings directly aside from each other and the elevators intruding into the beam at main deck level (if I can use the fact that the superstructure is sponsoned out to judge the position of that last one) This is not an carrier where the flight deck is the strength deck. because of that, if nothing else, this carrier is impossible as it is now.
In addition to that, if you choose to refine this problem, I note the complete lack of the gallery deck, my gut feeling tells me the funnel seems a bit on the small side and I really wonder about the use of bulges on an new hull, which could have been optimised for it's current beam and topweight from the start, could it not? I also wonder about the position of the guns on the flight deck, The liferafts only reachible from a quay, the boats all concentrated straight on top of the propellers, unusable in an emergency and how high up the anchors are, for some reason.

In short, to work, this ship needs quite an rework. I think the double hangar would have to go (in exchange for the topweight issues from the heavy armoured flight deck and the gallery deck) and her size might not be worth it anymore at the size the aircraft were at the time. (as in, compare the reasons the british did not have a ship this size, as they had armoured flight decks from the start....... hindsight is an evil thing, but the why not is an interesting question in itself)

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Krakatoa
Post subject: Re: Republic of Algarve.Posted: October 12th, 2016, 8:37 pm
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Thanks Ace that does give me some pause for thought. The main reason I figured nobody had bothered to build something this size was that it could not transit the Panama Canal, and would have had few docking points for hull work to be done.

Is there a difference in weight of what I would term builders steel and armoured steel of the same thickness? I am thinking about the flightdeck. in which a large area of steel needs to be stressed and supported to receive aircraft landing on at speed. Versus armour of the same thickness being used for the flightdeck. Something to do with density would be my guess, but it is something I have not read a lot about. It was one of the reasons I kept my armoured flightdeck to 1.5 inches (37mm) rather than the 4.5" inch of the Illustrious type. My thought for that was that any bomb/shell, with a delay (armour/semi-armour piercing), would be triggered by the thin flightdeck armour and explode above the main deck armour which would keep the core systems from damage and allow the ship to survive and be able to remove itself from harm. Would a bomb/shell passing through builders steel be triggered to explode in the manner I want (above the main armoured deck)?

The four deck edge lifts are just that, deck edged. They do not impact into the hull. Are you saying to keep strength I should have them staggered rather than opposite each other?

I am not sure if that is supposed to be a bulge or just the way Alex showed the armoured belt as it did not go low enough down the hull to really have a true bulge effect.

Interesting about the Malta's bridge, in other threads it had been figured the bridge had been split for aerodynamic reasons rather than stress relief. For stress relief for a hull, what sort of size are we talking about (of length/breadth) before these stress release actions are needed? Would the Essex have had the stress problem then jumping up to the Midway size did.

The double hangar size I worked at 24 feet for the lower and 22 for the upper hangar. The Illustrious type were 16 feet and with the indefatigable type squeezed an extra 14 foot lower hangar.

The big Admirals/Captains barge type sized boats are at the stern but the general covered work boats are on the gallery on the port side. The liferafts use the same pull/release system as the Southampton type cruisers (and lots of other types) where the liferaft is mounted on the outside of the hangar and released from inside the hangar. The anchors are directly from where they were mounted on a Malta, but may have crept up a bit in height with the higher hull. Lowering those is not a big job.

The funnel is fine, it is bigger in square footage than the two funnels of an Iowa put together.

I do not mind if a design of mine is a failure if I learn something from it.


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acelanceloet
Post subject: Re: Republic of Algarve.Posted: October 12th, 2016, 9:54 pm
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I am about to go to sleep, so you will have to ask me again later if I forget to reply to things, but a few things here:
- while there is a difference between armour steel and builders steel, I do know not enough about either to be certain about any good answer to the question. the way you describe an impact is very much part of carrier doctrine IIRC, with an armoured deck under the flight deck (especially since there are big holes in the flight deck and the hangar so bombs could go in) the early carriers even had an wooden flight deck, easy to repair while the armoured ship underneath it was not even hit because only the flight deck was impacted.
- it is an bulge, whatever it is meant to represent, that is not an armoured belt. it could be torpedo protection, but even then it is torpedo protection added as an aftertought. bulges can be there for 2 things: adding volume (so your ship can be heavier) or adding width at the waterline (so your center of gravity can be higher without the ship getting unstable). for the second variant, there is no need for it to go down.
- deck edged elevators still have an impact on the hull strength, mostly because they need holes in the hull soo large an aircraft can fit trough! (literally this time :P) which very much impact hull strength. having them staggered spreads this large weakness over a few cross sections instead of having at all in 1.
- both earodynamics and stress relief are true for the malta's bridge structure. there are ways of having expansion joints in an superstructure (look at that of the great liners, they all have expansion joints in their superstructure but from the inside you will never find them) so for earodynamics they most likely have chosen to split completely.
- as for expansion joints being required, has nothing to do with L/B but all with L/D (the depth described in my earlier post) essexes had the expansion in their upper levels, as had the midways. (see the transverse lines in front and aft of the superstructure in this pic, https://upload.wikimedia.org/wikipedia/ ... _1988.JPEG) forrestal had the flight deck as strength deck. the size limit seems to be somewhere in between those 2. fact is, even with an smaller ship, it is possible to build somewhat lighter but with higher topweight with the flight deck as strength deck. it all depends on the exact dimensions of your ship (here comes the beam in, on an wider ship you can have more topweight etc) even destroyer sized vessels of all ages have to keep this issue into account: superstructures apart, and the heightened forecastles had to be reinforced to avoid the large change in cross section (hence why flush deck ships were sometimes lighter then forecastle ships, but with higher topweight again :P)
- the iowa had less power (212 shp vs your 220) and an less ducted exhaust, though, so you will at the very least need a bigger one as that :P

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Krakatoa
Post subject: Re: Republic of Algarve.Posted: October 13th, 2016, 6:56 am
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I have read this article a few times and thought it was better to mount the strength deck at the main deck level, rather than the flight deck level. I am confused.

http://www.navweaps.com/index_tech/tech-030.htm

If I was designing a 1940's carrier would I go with the smaller UK builds of the Illustrious type with armoured flight decks (3" or more) or the US Essex type with light flight decks and armour at main deck level.

To build what I want, a 1200 foot carrier, I would have to go with the US type. For my drawing it means that in the statistics I would remove the 1.5" armoured deck and leave it as builders steel thick enough at the rear to take a landing aircraft. I will have to offset the elevator/lift arrangements. I will have to add a visible set of expansion joints, fore and aft of the bridge structure at about the 400 foot level. (between each fore and aft entry to the hangar.

Armament, it is still at a time when larger AA guns like the 4.5" are fitted, so they need to remain. The 40mm I either keep where they are or create a gallery deck off the edge of the hangar and mount them there (below the level of the flight deck).

I need to remove the 'bulge' and delineate the armoured belt better. I need to lower the anchors closer to the waterline. Maybe increase the size of the funnel by 10%.

Anything else? (other than start again ;) )

Oh - and recolour the hull..


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apdsmith
Post subject: Re: Republic of Algarve.Posted: October 13th, 2016, 9:14 am
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Hi Krakatoa,

To quote from the navweaps article:
Stuart Slade wrote:
Starting with the Forrestal class, the size of the carriers meant that stress requirements forced the abandonment of the external hangar and hangar deck as strength deck concepts. A shallow hull of that size is a design impracticality. In the Forrestal and after, the flight deck is the strength deck, protection considerations had no influence whatsoever on the flight deck design. In fact, these carriers do not have armored flight decks.
I would note that the described class is 15,000 tonnes lighter than your design, such considerations would appear to be even more important.

Also, as I understand it, structural steel and steel plate have a comparable density - but unless you're the US and using (expensive) STS everywhere in your construction, you need both to armour an area.

Regards,
Adam

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Krakatoa
Post subject: Re: Republic of Algarve.Posted: October 13th, 2016, 10:51 am
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Thanks for that Ad,

The only problem is the Forrestal is a late 40's early 50's design, and while we have excellent 20/20 hindsight, I may have to stick with what could be a fatally flawed design because the knowledge is not available to my designers in the late 30's.

The biggest carriers afloat at this time is the Lexington and Saratoga at 888 feet and 48,500 tons. Reading through the notes on them does not say if they are main deck or flight deck strength ships. But being built from BC's I would guess main deck as strength deck.

The other line I could follow is the Ark Royal (1937) which looks like it had the strength deck as an unarmoured flight deck. But I can't say for sure as this little bit of information does not seem to appear in the write-ups I have. Maybe one of the other members can enlighten us. Though it does say the hull goes right to the flight deck level with no break which would indicate the flight deck/strength deck scenario.

If the Ark Royal is a flight deck, strength deck, unit, then I do have a stream to follow. Otherwise my mega carrier could have a problem with cracking and have a very short life span.

Either way it looks like I have quite a large redraw to do.


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