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New French CVA

Old 10th Dec 2020, 15:16
  #21 (permalink)  
 
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At the risk of talking more gash - the island looks to be part way between a Nimitz class and Ford class position, if smaller and further inboard than a Nimitz. The model has vehicles parked outboard, I believe the original plans for CVA-01 to 04 had a two island design but one of the reasons they were consolidated was to provide sheltered parking for deck vehicles. The model also has four FJs 'marooned' astern of the island. I wonder if la Royale has considered using that "solution in search of a problem" the Alaska Highway - I believe Winkle Brown was a fan arguing it allowed for better deck management and facilitated simultaneous launch and recovery.

I also recall reading/hearing somewhere Winkle saying he was a fan of the twin island design (probably dating from his work on CVA-01) - he may of course have been influenced by his relative lack of sea time.

Given their experience with CdG and the UK's with the QNLZ class I think 11 years from start of development to launch in '36, with the aim of allowing two years sea trials before replacing CdG, is very sensible.
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Old 10th Dec 2020, 16:02
  #22 (permalink)  
 
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I suspect that the Alaskan Highway was one of those good ideas on a general arrangement drawing that might not have survived first contact with the chockheads who would have to maneuver a 30 te aircraft down the outboard side of the ship (where roll amplitude is magnified), in the dark, rain, spray etc and with little or no clearance between the island itself and the catwalk. At the risk of being burned as a heretic, Winkle was also a fan of the rubber deck / undercarriageless aircraft, which I have to say seems like a dead end. Or rather, an extreme palliative to a problem waiting for better airframe and engine technology.

The "marooned" aircraft would be where you'd leave your alert cabs. Easy unchain and taxi to cats from there, no need to get involved in the larger safe parking area which can deal with your cyclic deck ops.. It's not a fully representative deck spot either, as the portside cabs encroaching over the recovery line show.
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Old 10th Dec 2020, 20:44
  #23 (permalink)  
 
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Big boat for only two cats. Space behind the island is hard to use mid cycle - but can be used for spotting jets before first launch or when a recovery is complete - because landing jets need to clear LA quickly and cannot go aft until the last is on - therefore need deck space forward to hold the entire wave - and donít want to get in the way of Cat 1 either which will prob have the tanker on it.
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Old 10th Dec 2020, 21:44
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Not_a_boffin

Winkle Brown was probably influenced by his wartime experience of teaching pilots to land on carriers and doing carrier trials. The flexible deck was was an attempt to deal with the difficulty of precise landing and to separate landing and take off areas. It helped influence the invention of the angled flight deck.

The CVA-01 flight deck design was intended to take this further, and to reduce the difficulty for the pilot lining up. There are parallels with the design of the QEC flight deck.

orca

I suspect the extra size is for greater sea keeping - CDG had to stop operations off Libya at sea state 4. Maybe they hope to carry a squadron of ASW helicopters like other NATO carriers.

The lack of a bulbous bow in the artist's impressions is also odd. It adds buoyancy and aids launching aircraft by lifting the bow.
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Old 10th Dec 2020, 22:02
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Originally Posted by WE Branch Fanatic View Post
Not_a_boffin

Winkle Brown was probably influenced by his wartime experience of teaching pilots to land on carriers and doing carrier trials. The flexible deck was was an attempt to deal with the difficulty of precise landing and to separate landing and take off areas. It helped influence the invention of the angled flight deck.

The CVA-01 flight deck design was intended to take this further, and to reduce the difficulty for the pilot lining up. There are parallels with the design of the QEC flight deck.

orca

I suspect the extra size is for greater sea keeping - CDG had to stop operations off Libya at sea state 4. Maybe they hope to carry a squadron of ASW helicopters like other NATO carriers.

The lack of a bulbous bow in the artist's impressions is also odd. It adds buoyancy and aids launching aircraft by lifting the bow.
Nope. The flex deck was to reduce aircraft weight by removing the need for carrier capable undercarriage.

The lack of bulbous bow (although there is some novel form there) is probably down to Mr Froude.

A bulb doesn't lift the bow, if anything it damps pitch motion.
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Old 10th Dec 2020, 22:37
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Originally Posted by petit plateau View Post
Interesting... ...No bulbous bow.
I don't think the reflections from the display box helps but it looks to me as though there is a bulb there but it does not project from the bow.
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Old 11th Dec 2020, 00:14
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Originally Posted by WE Branch Fanatic View Post

The lack of a bulbous bow in the artist's impressions is also odd. It adds buoyancy and aids launching aircraft by lifting the bow.
Bulbous bows are found many ships. Basically they give better fuel efficiency and speed. Bouyancy by forcing the bow up would actually lead to more a inefficency and less speed. The bow wave generated by the bow and the bow wave from the bulb are 2 different waves, they make contact and counter act each other (destructive interference ) and the wave is destroyed
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Old 11th Dec 2020, 10:08
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Originally Posted by Not_a_boffin View Post
Nope. The flex deck was to reduce aircraft weight by removing the need for carrier capable undercarriage.

The lack of bulbous bow (although there is some novel form there) is probably down to Mr Froude.

A bulb doesn't lift the bow, if anything it damps pitch motion.
The flexible deck experiment contributed to the invention of the angled flight deck by Captain Dennis Campbell. As for the bulb - surely reducing pitch motion aids flying operations?
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Old 11th Dec 2020, 11:40
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Originally Posted by WE Branch Fanatic View Post
The flexible deck experiment contributed to the invention of the angled flight deck by Captain Dennis Campbell. As for the bulb - surely reducing pitch motion aids flying operations?
Driving factor behind flex deck was taking weight out of the aircraft to improve performance at the time (primarily due to contemporary airframe and engine technology). Driving factor behind angled deck was to overcome hazard associated with heavier faster aircraft exceeding capability of barrier to protect recovered aircraft on an axial deck.

Reducing pitch does help air ops, but not by "lifting the bow". You fit a bulb primarily to reduce wave-making resistance - influenced by a combination of ship length and speed - it comes with a resistance penalty at lower speeds, which you only pay if worth it. QEC is right in the sweet spot for one.
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Old 11th Dec 2020, 14:15
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Wouldn't a catamaran layout be the optimum concept for some aircraft carrier? However they might be too wide for existing docks and shipyard infrastructure.
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Old 11th Dec 2020, 15:01
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Originally Posted by Less Hair View Post
Wouldn't a catamaran layout be the optimum concept for some aircraft carrier? However they might be too wide for existing docks and shipyard infrastructure.
You'd find the motions somewhat limiting, the ability to provide enough volume in the bowels of the ship for fuel, munitions, stores etc very limited (and very difficult to arrange) and the damaged stability performance distinctly exciting. So no.
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Old 11th Dec 2020, 16:54
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Russia's looking at the very thing!

https://nationalinterest.org/blog/bu...carrier-105477

http://www.navyrecognition.com/index...ll-design.html


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Old 11th Dec 2020, 17:01
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More,m missing letters form blo gs pot

https://thaimilitaryandasianregion.b...t-carrier.html
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Old 11th Dec 2020, 17:49
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Originally Posted by Less Hair View Post
Wouldn't a catamaran layout be the optimum concept for some aircraft carrier? However they might be too wide for existing docks and shipyard infrastructure.
Several catamaran designs have been explored for aircraft carriers, and they do look very glorious on paper and renderings, with acres of parking space, multiple layout possibilities, including totally separate landing and take off areas, or even multiple "runways" but the building and maintenance docks, and as others point out the stresses and other factors quickly make them problematic. The size requirement for a graving dock or floating dry dock would be massive, and if that dock is full (or sinks/gets damaged as the Russians found out) you are out of luck.
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Old 11th Dec 2020, 20:48
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Originally Posted by Less Hair View Post
Wouldn't a catamaran layout be the optimum concept for some aircraft carrier? However they might be too wide for existing docks and shipyard infrastructure.
Yes that would be one big reason, the other is catamarans dont carry weight as well as a monohulls. While my experience is from the sailing side of things, catamarans they are easier and more susceptable to and more effected by overloading compared to monohulls
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Old 11th Dec 2020, 22:00
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Originally Posted by sandiego89 View Post
Several catamaran designs have been explored for aircraft carriers, and they do look very glorious on paper and renderings, with acres of parking space, multiple layout possibilities, including totally separate landing and take off areas, or even multiple "runways" but the building and maintenance docks, and as others point out the stresses and other factors quickly make them problematic. The size requirement for a graving dock or floating dry dock would be massive, and if that dock is full (or sinks/gets damaged as the Russians found out) you are out of luck.
This just seems lacking in imagination.
There is absolutely no reason why the hulls need to carry anything but the propulsion units plus lots of spare buoyancy. So they do not need to be included in the dry dock.
The nuclear power plant and the air detachment , along with the sensors would be in the mid body, lifted from below into the dry dock when necessary.
So no need for a super wide dry dock.
I do not know whether anyone has ever built a big cat, but it does seem a better way for aircraft to deploy than the enormously expensive and inefficient VSTOL designs we are currently saddled with.
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Old 12th Dec 2020, 12:28
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The one reason to not use catamarans might be that they don't fit the Panama and Suez channels and locks.
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