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Post by bcoopactual on Sept 16, 2018 6:52:15 GMT -6
Yeah britishball , I'm not trying to tell anybody what they can't do. I'm just stating that if we want to go above 18 inch guns, we're probably asking the developers to do it without having a lot of historical data to work with.
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Post by thatzenoguy on Sept 28, 2018 19:14:26 GMT -6
There's plenty of data around for the developers to use 20 inch+ guns. What's the source of this "plenty of data"? www.navweaps.com/Weapons/WNJAP_20-45.php;V Jap 20 inch guns are pretty decently explained. Just extrapolate the rest.
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Post by aeson on Sept 28, 2018 19:40:36 GMT -6
"There is little information available for these guns."
"There's plenty of data around for the developers to use [for] 20 inch+ guns."
Perhaps my command of the English language is failing me, but these seem to be fairly incompatible statements when the former comes from an article being cited as support for the latter.
Also, the page linked has little or no data on the gun's ballistic characteristics. There's enough information there where someone who knows what they're doing could probably create a theoretical model of the gun's performance, though they might still need information not given on the page (better information on the shells, for example) and some of the information on the page looks a bit spotty (the weight and bursting charge of the APC shell, for example, look like estimates rather than hard data for an actual Japanese 20.1" APC shell), but the page linked doesn't provide any real data on the gun's performance against which the theoretical model could be checked. More than that, reading the "Description" part of the article, it sounds to me like the Turret/Mount information at the bottom of the page is probably more akin to design requirements, probable design targets, or estimated reasonable performance for a turret of that size and weight based on performance of known Japanese turret machinery rather than something that a Japanese 20.1" twin or two-gun turret is known to have achieved.
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Post by sillygoy on Sept 28, 2018 21:01:40 GMT -6
Maybe the difference between 18- and 20-inch guns could be of the same scale as the difference between, let's say, 14- and 16-inchers?
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Post by aeson on Sept 28, 2018 22:39:16 GMT -6
Maybe the difference between 18- and 20-inch guns could be of the same scale as the difference between, let's say, 14- and 16-inchers? It's not particularly likely. Assuming the same general form and drag coefficients for each shell, a 16" shell would mass about 50% more and experience about 30% more drag than a 14" shell while a 20" shell would mass about 38% more and experience about 23% more drag than an 18" shell, so a 16" shell should have experience about 88% of the acceleration from drag that a 14" shell would at the same velocity while a 20" shell should experience about 90% of the acceleration that an 18" shell would at the same velocity. 20" shells would lose speed relative to 18" shells more quickly than 16" shells would lose speed compared to 14" shells, essentially. Especially when coupled with the the relatively smaller increase in mass, a 20" shell should probably have relatively less of a long-range penetration advantage and relatively less of a maximum range advantage over an 18" shell than a 16" shell would have over a 14" shell, assuming similar muzzle velocities and shell characteristics. If you wanted to base relative performance of a hypothetical 20" gun off a historical 18" gun based on the relative performance of historical guns, you'd probably be better off going with something like 18" and 41cm guns, as the mass and cross-section of an 18" shell should be to a 41cm shell roughly what the mass and cross-section of a 20" shell would be to an 18" shell and the guns and shells being scaled up aren't sufficiently dissimilar to the guns and shells whose performance you're trying to predict that scaling things up starts to become really suspect, as might be the case if for example you were to try scaling things up from 10" and 9" shells.
Also, this is getting kind of beside the point, which is that there isn't really much of any useful experimental data on the performance of extremely large-caliber naval rifles, at least not that is readily available. There are theoretical models out there which could perhaps be applied to analytically generate this kind of information for arbitrarily-large guns, but there isn't any experimental data against which the models can be checked once you start running the number for guns of calibers larger than about 18" and if I recall correctly the developers have expressed a certain degree of caution over relying on the predictions of theoretical models when there is no experimental data to back up the models' predictions at the scales under consideration, for example in their responses to requests to allow extremely large battleships. If you want to convince someone to include something and one of their objections to including it is that there is a lack of experimental data to back up the predictions of the theoretical models, "theoretical models can predict the performance for things on which we have no experimental data" isn't exactly a convincing argument for the inclusion of the thing in question.
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Post by thatzenoguy on Sept 29, 2018 7:05:21 GMT -6
"There is little information available for these guns."
"There's plenty of data around for the developers to use [for] 20 inch+ guns."
Perhaps my command of the English language is failing me, but these seem to be fairly incompatible statements when the former comes from an article being cited as support for the latter.
Also, the page linked has little or no data on the gun's ballistic characteristics. There's enough information there where someone who knows what they're doing could probably create a theoretical model of the gun's performance, though they might still need information not given on the page (better information on the shells, for example) and some of the information on the page looks a bit spotty (the weight and bursting charge of the APC shell, for example, look like estimates rather than hard data for an actual Japanese 20.1" APC shell), but the page linked doesn't provide any real data on the gun's performance against which the theoretical model could be checked. More than that, reading the "Description" part of the article, it sounds to me like the Turret/Mount information at the bottom of the page is probably more akin to design requirements, probable design targets, or estimated reasonable performance for a turret of that size and weight based on performance of known Japanese turret machinery rather than something that a Japanese 20.1" twin or two-gun turret is known to have achieved.
There's plenty of ballistic calculators for battleship shells, just nab one off Navweaps, plug in the 20 inch data, and bam, you have everything you need...
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Post by aeson on Sept 29, 2018 11:20:46 GMT -6
There's plenty of ballistic calculators for battleship shells, just nab one off Navweaps, plug in the 20 inch data, and bam, you have everything you need... There is a very big difference between experimental data and the predictions of theoretical models.
Also,
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Post by oldpop2000 on Sept 29, 2018 15:15:35 GMT -6
There's plenty of ballistic calculators for battleship shells, just nab one off Navweaps, plug in the 20 inch data, and bam, you have everything you need... There is a very big difference between experimental data and the predictions of theoretical models.
Also,
If actual testing data is not available, what does anyone do. Experts use the gun characteristics and ammunition data, then the formulas to calculate the theoretical firing data. After that, they build the gun, and test it. However, in our case, we don't actually have the data readily available. Now if someone wants to find the actually testing data for the German 53cm/52(21") Great 36, then we should be ok. This is a game, we have to use what is available. In Naval Weapons of World War 2 by John Campbell, Page 179 he has a brief summary of heavy caliber guns. This is the same data that is available at Navweaps. I have not seen any real data on the internet in reference to 20 inch guns. Personally, we should just use theoretical data, and be done with it. Simplify. There isn't anything we can do, if we want to build super-dreadnoughts with 20 in. guns.
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Post by aeson on Sept 29, 2018 16:32:12 GMT -6
If actual testing data is not available, what does anyone do. Experts use the gun characteristics and ammunition data, then the formulas to calculate the theoretical firing data. After that, they build the gun, and test it. However, in our case, we don't actually have the data readily available. Now if someone wants to find the actually testing data for the German 53cm/52(21") Great 36, then we should be ok. This is a game, we have to use what is available. In Naval Weapons of World War 2 by John Campbell, Page 179 he has a brief summary of heavy caliber guns. This is the same data that is available at Navweaps. I have not seen any real data on the internet in reference to 20 inch guns. Or the developers could simply not include 20" guns and only use guns for which there is real data available, because there's really not any particularly good reason to bother including 20" guns in the first place. It's very unlikely that such heavy guns would be useful for anything other than prohibitively-expensive vanity projects and questionable designs such as Fisher's 'large light cruisers,' especially if the guns are only going to be available very late in the game when battleships ought to be well on their way to being eclipsed by carriers - all the more so if 15"-16" guns continue to be heavy enough to defeat any armor that the computer actually puts on its ships and aren't that far off from defeating any armor that can be put on a ship.
Also, I am not saying that theoretical models should not be used, but claiming that there is "plenty of data" out there about the performance of 20" or similar guns is disingenuous when what is meant is "there might be just about enough information to run through some theoretical models to generate predictions of the performance of such weapons."
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Post by oldpop2000 on Sept 29, 2018 16:53:18 GMT -6
If actual testing data is not available, what does anyone do. Experts use the gun characteristics and ammunition data, then the formulas to calculate the theoretical firing data. After that, they build the gun, and test it. However, in our case, we don't actually have the data readily available. Now if someone wants to find the actually testing data for the German 53cm/52(21") Great 36, then we should be ok. This is a game, we have to use what is available. In Naval Weapons of World War 2 by John Campbell, Page 179 he has a brief summary of heavy caliber guns. This is the same data that is available at Navweaps. I have not seen any real data on the internet in reference to 20 inch guns. Or the developers could simply not include 20" guns and only use guns for which there is real data available, because there's really not any particularly good reason to bother including 20" guns in the first place. It's very unlikely that such heavy guns would be useful for anything other than prohibitively-expensive vanity projects and questionable designs such as Fisher's 'large light cruisers,' especially if the guns are only going to be available very late in the game when battleships ought to be well on their way to being eclipsed by carriers - all the more so if 15"-16" guns continue to be heavy enough to defeat any armor that the computer actually puts on its ships and aren't that far off from defeating any armor that can be put on a ship.
Also, I am not saying that theoretical models should not be used, but claiming that there is "plenty of data" out there about the performance of 20" or similar guns is disingenuous when what is meant is "there might be just about enough information to run through some theoretical models to generate predictions of the performance of such weapons."
As I reviewed my books and historical documents on naval guns, there is one item that most people don't possibly think about and that is blast effect. Simply, ships have to be lengthened to reduce the effects of blast from superfiring guns. The bigger the gun, the bigger the blast effect so now you have to increase the length. This increases the tonnage due to extended hull. It means the citadel has to be increased and so does the armor protect. It begins to become exponential. The Yamato's are an example. I suspect this and other factors including the production problems and storage problems of such large weapons might have made the decision for developers. This along with the fact that a dive bomber could carry a 1000 lbs. AP bomb which could at least do some real damage to the decks. In other words, the advent of the aircraft and carriers, both land based air and sea based air had a decided effect on development. Another factor is the additional cost and the need to build or extend current dockyards. This all figures into the mix. I agree, about not finding any real data. That does not mean there isn't any, I just can't find it. Believe me, I am pretty good at digging this stuff up. However, except for the Gustav that the German's built, I have seen anything that shows the data. The Japanese data might have been destroyed, I don't know.
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Post by axe99 on Sept 29, 2018 17:06:43 GMT -6
On very large guns, were there any railway guns of 20" of so? I'm not aware of any, but I'm pretty clueless when it comes to railway guns (even moreso than when it comes to me and naval guns - if there were, and if they were of a similar purpose (ie, 20" mortars wouldn't help us much) than that might provide useful data? As Oldpop well says, blast effects would have been horrendous!
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Post by oldpop2000 on Sept 29, 2018 17:24:08 GMT -6
On very large guns, were there any railway guns of 20" of so? I'm not aware of any, but I'm pretty clueless when it comes to railway guns (even moreso than when it comes to me and naval guns - if there were, and if they were of a similar purpose (ie, 20" mortars wouldn't help us much) than that might provide useful data? As Oldpop well says, blast effects would have been horrendous! The Schwerer Gustav - en.wikipedia.org/wiki/Schwerer_Gustav
D.K. Brown states that lengthening the ship to account for blast effects would affect cruising power and more fuel would be needed. Separation of end turrets would increase the weight of armor which would go up considerably. He states that a blast effect of 30 lbs. per square foot was the greatest pressure that could be tolerated. This would eliminate open sighting roofs.
Estimates for the Japanese 18 inch guns was that the blast effect would blow the skin off anyone within 15 meter radius.
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Post by ccip on Sept 29, 2018 20:01:37 GMT -6
For my two cents... I'm pretty ambivalent about 20in guns! I can understand both sides of the argument here, and the main reason I wouldn't dismiss them out of hand is that even with no actual examples built, there were a number of historical design proposals on drawing boards featuring hypothetical 20-inchers during the given timeframe of the game. All the same, I personally wouldn't miss them if they weren't there.
Also, while I'm not sure if this is actually a real issue - but my hunch is that from the perspective of game AI, "less is more" may be a better approach. If the AI suddenly had to "think" about two extra calibers of guns on the table when designing ships, that might give it more chances of getting it badly "wrong", and/or more situations where the AI ship designer would have to "cheat" slightly to balance out armament and protection. If that's so, then I'd rather be restricted to 18in maximum, than having a game where there's more opportunities to exploit AI design imbalances (or be exploited by them). Again, this might not be a real issue at all, but I'm just putting that consideration out there. I'd rather have a slightly more limited but slightly more balanced RTW 2, myself!
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Post by Fredrik W on Sept 30, 2018 10:40:18 GMT -6
There will be 20 in guns in RTW2, and I feel reasonably confident the AI can handle them.
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Post by oldpop2000 on Sept 30, 2018 11:04:53 GMT -6
There will be 20 in guns in RTW2, and I feel reasonably confident the AI can handle them. To Fredrik: Will the games ship designer, take into account that a ship with 20 inch. guns will have to be longer, the armor belt and the citadel will have to be bigger which will add to the weight and this will require more engine power. All this will increase the cost dramatically. I have taken my Yamato battleship design in Springsharp and made the appropriate changes for a 20 inch guns. It does change everything. I am still working on the original design to get the weights correct so then my second design will be closer to reality. Thanks for providing the information Old pop
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