Accurate Lengths Of IJN ships ?

[Captain_AJ]

I have been looking through prior post about the subject of correct length and heights of IJN Ships .. What I have been using is from a publication of actual sizes of certain classes of Of ships . It appears to be very confusing that the actual historical facts of these ships are not the same in prior post dated back in 2007 . for example the factual length of a Mogami heavy cruiser shows a length 620 , In the prior post it shows 320 , What I am I missing here . any help would be appreciated

[propbeanie]

Neither figure is correct, according to these guys:
http://combinedfleet.com/ships/mogami

it is what it is. Now, what files are you pulling your figures from in the game?... Any mods installed?

[Captain_AJ]

Yes Iam using Fortrs .. I will check out your link

[propbeanie]

Once we "finalize" the mod, CapnScurvy will most likely have an OTC mod ready to go shortly thereafter, if that's what you're after.

[Rockin Robbins]

And of course keep in mind that US records of Japanese ships were notoriously defective, both because of bad guesses and Japanese secrecy. More than half the targets shot at during the war, according to JANAC, were misidentified. Those which were properly identified often had grave errors in the recognition manual.

The American method of shooting torpedoes with stadimeter and position keeper was fatally flawed because stadimeters were difficult to begin with and our information on actual target measurements was incomplete and innacurate.

That, plus the American tendency to shoot from too far away, is why American shooting, torpedoes per hit and torpedoes per ton sank, were so much worse than the Germans. German shooting techniques did not demand target identification.

[wolfman Ben]

i wish i could help

[Captain_AJ]

Than I suppose .. I have learned that no matter the link having the correct plot and were the ship will end up I can use the zero method .. but if your sub is sitting about 4000 yards from the target , scope and using that scope can determine . AOB ,, speed .. , knowing what is true ratio aspect of what is known data, It will help in caculations of shooting , let's say on a 70 degree angle , the scope in FOTORS has the tick marks that can get you data and using a formula that will determine AOB , distance without using a plot . on a map ,however this method will be usefull in bad weather --- I just sank a fubki destroyer , without using a scope ,,

But . what is required is the known aspect ratip of a ship length divided by height which is not shown In SH4 , and than determining by the scope of what is seen in the moment = AOB , distance , and speed which is another caculation , of knowing the true length of a ship . this requires a formula of seeing tic marks , divided by what you see in the scope (L/H) x 100 /known aspect ratio which will give a percentage of AOB , versed against a sine chart that will determine AOB ..

What I need to know is the correct Length which SH5 is modeld in the book of ships , only in SH4 is the mast height is given , and were will i find this ? , were will I fins the correct length of the ships ? that as the purpose of this thread .

[aanker]

Optical Targeting Correction
CapnScurvy

http://www.subsim.com/radioroom/showthread.php?t=181172
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

[propbeanie]

Well, in SH4, the Game / Data / Sea / Ship / Ship.cfg file has the "stats" for the vessel, though they don't use most of those in the game, and they are not accurate, as you've discovered. CapnScurvy, if he does an OTC mod for FotRSU, would most likely take the catalog of ships at that time, and attempt to find data that's more accurate for his mod. I have no idea what his "source" would be, but that's the only way to get the real info, is to research and gather. I'm sure any of the existing OTC mods would have a percentage of the vessels in FotRSU, though not all of them.

[LCQ_SH]

German shooting techniques did not demand target identification.

Is that so?? Is there any good piece of literature I can read about that?? :D

:salute::salute:

[Captain_AJ]

I appreciate the effort of posting the information about the optical mod , However I am using FOTRS I would used this mod if this was compatable with FOTRS

[Rockin Robbins]

I appreciate the effort of posting the information about the optical mod , However I am using FOTRS I would used this mod if this was compatable with FOTRS

Upon completion of FOTRSU, we will be issuing guaranteed compatible FOTRSU Plugin Mods. Among them will be OTC. The Capn may rename it or anything he chooses to do with it, but it will be available for anyone who wishes to use it.

[Rockin Robbins]

Is that so?? Is there any good piece of literature I can read about that?? :D

:salute::salute:

Germans used what Americans call constant bearing techniques, aiming at a point that the enemy must pass with targeting methods where range, and thus target identification, cancels out of the equation. You COULD ID the target if you wished. It didn't matter. You still hit the target.

Go to the SH3 forum and search for "Fast 90." You can also read "Clear the Bridge" by Dick O'Kane, where he describes the technique. I don't think he explains that the technique came from the U-Boats, but Eugene Fluckey in "Thunder Below" wasn't bashful about saying it at all. American skippers studied the accomplishments of U-boat skippers to learn anything they could, in order to do better.

[Captain_AJ]

Upon completion of FOTRSU, we will be issuing guaranteed compatible FOTRSU Plugin Mods. Among them will be OTC. The Capn may rename it or anything he chooses to do with it, but it will be available for anyone who wishes to use it.


well that is something that iam looking for .. btw have you checked out that book the enemy below? .. seems us as virtual skippers shared the same situations as real life skippers when it come to torps becomming , duds and misses -- thanks

[LCQ_SH]

Germans used what Americans call constant bearing techniques, aiming at a point that the enemy must pass with targeting methods where range, and thus target identification, cancels out of the equation. You COULD ID the target if you wished. It didn't matter. You still hit the target.

Go to the SH3 forum and search for "Fast 90." You can also read "Clear the Bridge" by Dick O'Kane, where he describes the technique. I don't think he explains that the technique came from the U-Boats, but Eugene Fluckey in "Thunder Below" wasn't bashful about saying it at all. American skippers studied the accomplishments of U-boat skippers to learn anything they could, in order to do better.


I guess these techniques refer or should be related to 0° gyro angle attacks and the "four bearing" methods, right? I mean, for a u-boat that is easy to do without a radar as their hydrophone had a range for convoys around 30-50 NM which gives you enough time to determine course and speed.

Is that true that American hydrophone was so much less capable than German's by only being capable to pick up ships at 10K yards? the four bearing method and 0° gyro attacks by hydrophone listening are possible for a very slow moving ship. Late in the war subs had radar, but before radar, how was that possible? :hmmm:

[propbeanie]

I guess these techniques refer or should be related to 0° gyro angle attacks and the "four bearing" methods, right? I mean, for a u-boat that is easy to do without a radar as their hydrophone had a range for convoys around 30-50 NM which gives you enough time to determine course and speed.

Is that true that American hydrophone was so much less capable than German's by only being capable to pick up ships at 10K yards? the four bearing method and 0° gyro attacks by hydrophone listening are possible for a very slow moving ship. Late in the war subs had radar, but before radar, how was that possible? :hmmm:

Observation. I do it in an S boat in SH4. A lot depends upon where you are versus where a target is when sighted, but it is possible to "get in position" in plenty of time, under the proper circumstances. You do miss more opportunities than you get though. My only issue is that an S boat has a ~slightly~ more difficult time getting away from a 1k yard or less shot though... :03:

[CapnScurvy]

Well, in SH4, the Game / Data / Sea / Ship / Ship.cfg file has the "stats" for the vessel, though they don't use most of those in the game, and they are not accurate, as you've discovered. CapnScurvy, if he does an OTC mod for FotRSU, would most likely take the catalog of ships at that time, and attempt to find data that's more accurate for his mod. I have no idea what his "source" would be, but that's the only way to get the real info, is to research and gather. I'm sure any of the existing OTC mods would have a percentage of the vessels in FotRSU, though not all of them.

My "source" is the actual game itself. Nothing in a "real life reference book" can be used to replicate measurements if a game measurement is different than what the real world measurement is stated as. AND, that's exactly what you have with this game.

A meter is not a true meter, a yard does not measure 36 inches (3 feet), and so on. You're barking up the wrong tree to think you can use "real life" measurements with this game ,and add up to true accurate measurements......won't happen!:up:

[Rockin Robbins]

In order for OTC to work correctly, CapnScurvy actually makes a mission, puts the ship in it and measures it, ship by ship to have the game recognition manual and TDC have the exact measurements. That means if you import new ships in your game OTC won't have the data.

But real ships have nothing to do with it. OTC works because its data exactly matches the ship models in the game.

[Pisces]

I guess these techniques refer or should be related to 0° gyro angle attacks and the "four bearing" methods, right? I mean, for a u-boat that is easy to do without a radar as their hydrophone had a range for convoys around 30-50 NM which gives you enough time to determine course and speed.

Is that true that American hydrophone was so much less capable than German's by only being capable to pick up ships at 10K yards? the four bearing method and 0° gyro attacks by hydrophone listening are possible for a very slow moving ship. Late in the war subs had radar, but before radar, how was that possible? :hmmm:4-bearing methods are totally unrelated. They might not even be historically accurate used in the game. At least, I haven't heard any of such in all the discussions here on subsim. Just because the game provides bearings in degrees doesn't mean the real hardware could pinpoint a target that well. We can use it because mathematics is ageless, and the user interface developers were kind to us.
The target being far or close does not help in determining a proper solution. For bearing-only methods to work well you need precisely defined bearing angle in reasonable time frames. You can do with less precise bearing if the time interval is increased. Or else it just tells you the target is going N-E-S-W-ish/in a wide arc/halfway omni-directional. The knowledge of sound propagation physics and technology level just was't so cooperative as in this digital/electronic age. Though I would guess it possible for them in that time to make a mechanical analog calculator for it. It's the input part that makes it unreliable.

I supposed the constant bearing method comes closest to '0-gyro angle' as that is how Dick O'kane's method is usually executed. But it doesn't have to. As long as the visual 'firing cue' bearing of the periscope is offset from the chosen torpedo track or gyro angle by the right amount of lead (generally speaking it only depends on target speed, AOB and torpedo speed), then it should hit despite the range of the target. (caveat any parallax correction due to the torpedo track curve and periscope offset from the torpedo tubes) If the target is further away, it also has farther to travel to the impact point. And so does the torpedo have the same time to get there! With the lead set up properly you only have to wait for the target to pass the periscope cue line. That is the concept of 'constant bearing'. The fact that 0-gyro angle makes setting this up more easily and avoids the torpedo-track-curve correction is the reason that this is the popularly choice of doing so.