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Post by Antediluvian Monster on Apr 11, 2020 9:00:33 GMT -6
christian I'd advise taking some of the figures at Navypedia with grain of salt, the Japanese carriers at least are off in many respects. For example it's saying Shokaku had 7.000 m2 hangar floor, but they actually had usable floor of 5.545 m2. It's also claiming they had 1.800 (!) tonnes of aircraft fuel, but they actually had 496 tonnes.
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Post by oldpop2000 on Apr 11, 2020 9:11:57 GMT -6
One of the major issues that the British and US naval architects were dealing with is the weight of the armored deck and its affect on the metacentric height. The difference between the center of gravity and center of buoyancy is that metatcentric height. The larger the difference, the faster the ship snaps back during a roll, but it also means the ship rolls more. Carrier don't like to roll as it makes launching and recovering harder and more touchy. So, the only solution is to lower the freeboard. That is the distance from the Wl to the main deck. The main deck on an aircraft carrier is the hangar deck. The British had this issue with the class following the Illustrious. We had it with the Midway class. Lowering the freeboard has the effect of making the ship wet and believe me the Midway was wet forward. I've been on the Midway twice in the museum role and worked on her at Alameida before she was decommissioned and the sailors told me she was wet especially in heavy seas.
For British, they were dealing with an armored deck, armored main deck and armored side. The Midway class had just the armored flight deck and armored main deck or hangar deck. However, both had to have their freeboard lowered. The formula that has been offered in Brown's book is the square root of the length times 1.1. Later designs state that the formula is now the square root of the length times 1.3 but it is still very close.
So, this is the issue besides the added structural components to support the heavy deck. The British had to lower the hangar deck ceiling which is the armored flight deck. However she still had to have enough room for the larger aircraft that were being developed.
Its a compromise of factors, and it isn't easy to try to satisfy all requirements and still keep the ship within a reasonable displacement and size. We had the advantage of advanced welding techniques which gave our ships far more structural strength than the British.
I am still researching this information.
Hope this helps to clarify.
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Post by Antediluvian Monster on Apr 11, 2020 9:43:32 GMT -6
Japanese also had the top weight issues with Taiho and actually cut a whole deck off the ship in comparison to Shokaku. Overall freeboard was lowered to one more in line with the much smaller Soryu family, and a hurricane bow familiar from the British AFD carriers adopted. They did manage to squeeze in comparatively tall 5m hangars though, and hangar height was a bane of these designs, particularly on the double hangar ones.
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Post by oldpop2000 on Apr 11, 2020 11:47:50 GMT -6
Japanese also had the top weight issues with Taiho and actually cut a whole deck off the ship in comparison to Shokaku. Overall freeboard was lowered to one more in line with the much smaller Soryu family, and a hurricane bow familiar from the British AFD carriers adopted. They did manage to squeeze in comparatively tall 5m hangars though, and hangar height was a bane of these designs, particularly on the double hangar ones. Yes, good point. I haven't been able to head to my Japanese navy books but I will. When I calculated the freeboard for the Midway, based on both formulas, it was 34.22 feet with the 1.1 formula, and 40.44 with the 1.3. This corresponds to the Essex class and that is what Friedman says. My issue is if they were the same, then why was Midway wet? Anyway, that is the information that I have.
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Post by christian on Apr 11, 2020 12:12:20 GMT -6
christian I'd advise taking some of the figures at Navypedia with grain of salt, the Japanese carriers at least are off in many respects. For example it's saying Shokaku had 7.000 m2 hangar floor, but they actually had usable floor of 5.545 m2. It's also claiming they had 1.800 (!) tonnes of aircraft fuel, but they actually had 496 tonnes. true was confused as to how a shokaku could carry less than 90 planes while midway sat at 137 with comparative hangar size (deck parking is not enough for 50 planes) either way dosent change much in general the japanese tended to have top heavy issues due to multiple reasons but yeah armored decks is a problem also limits hangar height
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Post by oldpop2000 on Apr 11, 2020 12:34:49 GMT -6
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Post by jeb94 on Apr 11, 2020 21:24:34 GMT -6
Japanese also had the top weight issues with Taiho and actually cut a whole deck off the ship in comparison to Shokaku. Overall freeboard was lowered to one more in line with the much smaller Soryu family, and a hurricane bow familiar from the British AFD carriers adopted. They did manage to squeeze in comparatively tall 5m hangars though, and hangar height was a bane of these designs, particularly on the double hangar ones. Yes, good point. I haven't been able to head to my Japanese navy books but I will. When I calculated the freeboard for the Midway, based on both formulas, it was 34.22 feet with the 1.1 formula, and 40.44 with the 1.3. This corresponds to the Essex class and that is what Friedman says. My issue is if they were the same, then why was Midway wet? Anyway, that is the information that I have. I would think that the answer lies with the hull design and the following reconstruction and massive increase in displacement. As built Midway was only 45,000 tons displacement with a hull similar to the Montana class battleship. She had bulges added and had a huge increase in flight deck size amongst her many modifications to balloon her displacement to 64,000 tons by the time she decommissioned. She was wet, tended to roll heavily in moderate seas, and was badly overweight. There was a reason why Coral Sea never saw the same amount of reconstruction. Fun fact, as built the super carrier Forrestal displaced 60,000 tons. 4,000 tons less than the smaller Midway’s final displacement.
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Post by oldpop2000 on Apr 12, 2020 8:06:49 GMT -6
Yes, good point. I haven't been able to head to my Japanese navy books but I will. When I calculated the freeboard for the Midway, based on both formulas, it was 34.22 feet with the 1.1 formula, and 40.44 with the 1.3. This corresponds to the Essex class and that is what Friedman says. My issue is if they were the same, then why was Midway wet? Anyway, that is the information that I have. I would think that the answer lies with the hull design and the following reconstruction and massive increase in displacement. As built Midway was only 45,000 tons displacement with a hull similar to the Montana class battleship. She had bulges added and had a huge increase in flight deck size amongst her many modifications to balloon her displacement to 64,000 tons by the time she decommissioned. She was wet, tended to roll heavily in moderate seas, and was badly overweight. There was a reason why Coral Sea never saw the same amount of reconstruction. Fun fact, as built the super carrier Forrestal displaced 60,000 tons. 4,000 tons less than the smaller Midway’s final displacement. You are correct, Coral Sea was stationed in Japan because the Japanese would not allow nukes into her ports. She was replaced by Kitty Hawk eventually.
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Post by oldpop2000 on Apr 12, 2020 10:53:39 GMT -6
Historically, after the war, carrier design changed because geopolitics changed and weaponry changed. In the world, we and the British were the only nations with sizable carrier forces. There were no reasonable carrier threats from other carriers. Along with this, was the advent of nuclear weapons. These weapons were tested at Bikini and this changed carrier designs. It also changed the ordnance loads on the carriers. They carried more nuclear bombs and less chemical ordnance. The aircraft changed, this began with the US Navy developing the A3 Skywarrior which was a twin-engine nuclear bomber. The carrier designs after the defunct USS United States were the Forrestal and the follow-on designs, the Kitty Hawk. The Midway class, only three build, were designed and built in the war period and thus were built for a different geopolitical situation.
This is only partially duplicated in the game. But this is how things went in the early and mid 1950's. Vietnam was a surprise and it forced us to change the ordnance loads and modify our strike aircraft for a new purpose.... land combat air support. It changed the game. Another factor that changed the game was nuclear power and the cost of the new carriers in the new naval budgets.
Again, some of this is duplicated in the game.. geopolitical change, technological change and economic change.
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