wiki says Japanese carrier Akagi originally had '3 flight decks'

Discussion in 'Boat Design' started by Squidly-Diddly, Feb 24, 2012.

  1. Squidly-Diddly
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    Squidly-Diddly Senior Member

    and this painting shows biplane coming out from open ended hanger below.

    Did they have an open hanger/flight deck in the stern???

    I could see launching planes out the back, even with air speed penalty, but I don't see being able to LAND planes into a tunnel.

    Maybe catapults for seaplanes in the stern?

    I guess I could see some advantages to having 3 flight decks, so all planes could launch quickly for an attack or defense.

    Maybe the higher powered fighters could launch out the back even when ship had considerable forward airspeed?

    [​IMG]
     
  2. hoytedow
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    hoytedow Wood Butcher

  3. tom28571
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    tom28571 Senior Member

    Squidly,

    Do you have confiration of this or is it just conjecture? The picture only shows a biplane sitting near the end of the second deck. Planes taking off from this second deck would not get the aid of carrier forward motion. And launching toward aft makes no sense at all.
     
  4. thudpucker
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    thudpucker Senior Member

    If it is true, the Japs certainly thought they could get within range, so the Bi-Planes would be effective and not just 'target practice' for the Allies.
    Japan's WWII and earlier Chinese wars reinforce the what can happen if the Leadership is always leading themselves to greatness. Ignoring the advances of the Enemy.

    Nice painting though.
     
  5. Squidly-Diddly
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    Squidly-Diddly Senior Member

    that video can't be Akagi because it was sunk in deep water and

    the painting is of it BEFORE the 1930s change to 'single flight deck'.

    http://en.wikipedia.org/wiki/Japanese_aircraft_carrier_Akagi

    I don't see why they would have an open bow 'hanger deck' with all sorts of spray coming in and why a plane would be out their unless they were launching it.

    I believe it would get airspeed benefit depending on how much the 'tunnel deck' was open all the way to the stern.

    Maybe wiki just means "hanger deck" and this was written by a Japanese not native English speaker.

    But I do think they were running a double decker flight deck at least on launch and maybe slow flying biplanes made that possible.

    Maybe something to consider with catapults.

    Too bad only US Navy seems to be able to afford them and everyone else uses skateboard ramps.:p


    HERE WE GO....originally had two short take off decks stepped below main 'landing deck'. Crazy! The painting must have been after guns and 'office' was mounted in the very short 'mid-level' landing deck. Yeah, I'm pretty sure the low stall speed of the biplanes must have made all this possible.

    But I bet the "work flow" from landing deck to re-arm and re-fuel to re-launch might have been pretty fast and smooth compared to conventional layout of the day, AND you could launch planes from three decks as I doubt those biplanes left to much turbulence wake.

    http://en.wikipedia.org/wiki/File:JapaneseAircraftCarrierAkagi3Deck_cropped.jpg

    http://upload.wikimedia.org/wikiped...JapaneseAircraftCarrierAkagi3Deck_cropped.jpg
     
  6. tom28571
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    tom28571 Senior Member

    Can't imagine a hanger deck so open as to allow full air flow. Makes no sense. There is also the three biplanes taking off together from the flight deck that is suspect. I expect there is quite a bit of artistic liberty taken here.

    Just looked through Wiki and there are a couple of photos and write up that say the picture is of a configuration that was never built. The three flight decks were staggered fore and aft at the bow. This allowed flow of air over the two lower decks and the possibility of take off from the lower decks while landing is happening on the upper deck. With the advent of more demanding aircraft all this was scrapped and only one deck was in place in the 1940's.
     
  7. Squidly-Diddly
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    Squidly-Diddly Senior Member

    Tom, did you look at the links to photos at the end of my last post?

    they clearly show an 'as built' ship at high speed, sporting two forward launching decks stepped down from the larger main landing deck.

    So at least they would be able to have three types of planes each ready to 'go next' without a lot of jockeying for position and could be launching from the other two decks while planes were being brought into position on the other deck.

    I guess the two launch decks had 'barn doors' of some sort at the rear wall to allow planes to come out from hanger decks, and I guess they had a three story elevator instead of just two story, at least for most forward and lower deck.....or at least two elevators staggered to move planes from landing to 'bow deck'.

    You are right that all this didn't include any of the lower launching decks open all the way to the stern, but I'm not 100% sure.
     
  8. tom28571
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    tom28571 Senior Member

    Yes I did look at those photos Squidly. That is what my post said about the three staggered forward flight decks, or so I thought. As for these decks being open all the way to the stern, that would never happen. Space on any ship is much too valuable for that to ever happen.

    Thanks for bringing this up though. Very interesting. Spent almost 3 years on a Destroyer with much of it involved in carrier operations off Korea during the unpleasantness there. Perhaps that is why I'm so skeptical of the practicality of these novel situations.
     
  9. bntii
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    bntii Senior Member

    Take a look at this:

    [​IMG]

    The section Flight deck arrangements here:

    http://en.wikipedia.org/wiki/Japanese_aircraft_carrier_Akagi

    Has some description of the design.

    "As completed, the ship had two main hangar decks and a third auxiliary hangar with a total capacity of 60 aircraft. The third and lowest hangar deck was only used for storing disassembled aircraft. The two main hangars opened onto the middle and lower flight decks to allow aircraft to take off directly from the hangars while landing operations were in progress on the main flight deck above."

    It sounds and looks like to me that the deck hanging over the bow could launch, but only the top deck could take landing aircraft.

    Here is another photo showing the forward flight deck:

    [​IMG]
     
  10. JRMacGregor
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    JRMacGregor Junior Member

  11. JRMacGregor
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    JRMacGregor Junior Member

    I am not so sure about that.

    A full air flow with lots of ventilation is a nice thing on an aircraft carrier with a lot of aviation fuel onboard. A really good ventilation system would be needed on an enclosed hangar deck that allowed aviation fuel to be handled there. With an open hangar deck, the chance of an explosive air/hydrocarbon mixture building up is much less. Fires and/or explosions on the hangar deck were costly for several navies.

    If I am not mistaken, the war winning ESSEX class design of the US had an open hangar deck (at least initially) - I think all the way from bow to stern (closed at the sides obviously). IIRC this allowed the aircraft engines to be warmed up on the hangar deck, which would have been very dangerous in a fully enclosed hangar.
     
  12. tom28571
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    tom28571 Senior Member

    Not saying that air flow is blocked on the hanger deck, just that full flow is not allowed there. Can you imagine trying to work on aircraft there with 29 knots of hull speed plus whatever ambient wind speed there is blasting at you. 60 knots of relative wind could be very common. 29 knots is, or was, normal launch speed when I was there. 29 knots was normal launch speed because that is what the escorting destroyers could make on 2 boilers, which is 1/2 the total and the number normally powered up.
     

  13. mydauphin
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    mydauphin Senior Member

    This all changed as airplane became faster and heavier. These biplanes weigh under couple thousand pound, WW2 planes about 10,000lbs , today's planes are an easy 40-60k lbs. Big difference when you have to put 30 or 40 planes on deck. Take off and landing speeds went up as well.
     
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