Lenght of ship

[Rockin Robbins]

Originally Posted by Pisces

It's not bogus, it's scientifically sound.

I looked up "bogus" in the Rockin Robbins unabridged dictionary and it said "historically unjustified procedure." My post wasn't to tell the OP not to use the technique, but that actual use of that technique was impossible during the war.

The Germans had the capability to use this technique. They were fighting open societies which did not restrict or falsify information about their merchant ships. A Liberty Ship, for instance, was a cookie cutter thing where each ship shared waterline length, overall length, masthead heights and cabin configurations. It wouldn't be difficult at all to determine the numbers by trial and terror and then apply those numbers to hundreds of available targets with devastating results. But I haven't seen evidence of much or any use of this technique, even by them.

Japan, however, was a closed society. Very little was known about their merchant fleet. We knew some things about their war fleet but much of that information was purposely misrepresented. The state of global communications just didn't allow us to use "timing by the wire" or to calculate target speed by prop turn count as we can today.

But don't confuse putting something in historical perspective with telling a new player not to learn the technique. I did not do that. In fact, I joked that now that I had rained on his parade he could continue collecting information.

[TorpX]

I had worked out the technique years ago when I was still playing SHCE. I thought, at the time, it was a brilliant idea and that it would be a great help to me. I soon stopped using it. Why? Not because it was ahistorical, but because I didn't see any advantage to it.

If the target is abeam, one must 'add' the sub's speed to the target's. If the target is ahead this is not neccessary, but then your already lost your window of opportunity. If the target is far away, it will be hull down and you can't use it. If the Aob is small, you can't really tell when the stern passes the wire. When you put your boat on a normal approach course, frequently, the target will be moving very little, relative to the wire, making the technique unusable. In any case, I would still have to make a plot to obtain the course and range, so I would use it for the speed also. The timing target length, or whatever you want to call it, will not give you any information that you can't get form a good plot.

That said, I don't see anything wrong with using it. It may be ahistorical, but it is not implausible. Certainly, at least some of the IJN warships were distinctive and would permit its use.

[gutted]

The ship lengths that were in the printed manual were off. I created a tool that will fetch all the data you'd possibly need about each ship from the actual game files:

http://www.subsim.com/radioroom/down...o=file&id=1602

It was made for SH5, but will work for SH4 as well.

enjoy.

[TorpX]

Good idea!

[CptChacal]

Originally Posted by razark

Some interesting statistics regarding that issue:

Unrestricted Warfare, Appendix 3, Page 1:

Unrestricted Warfare, Appendix 3, Page 2:

Wasn't JANAC controversial? I think O'Kane mentions at the end of his book that JANAC was discredited after checking with IJN records. Then new tonnage was credited.

[razark]

Originally Posted by CptChacal

Wasn't JANAC controversial? I think O'Kane mentions at the end of his book that JANAC was discredited after checking with IJN records. Then new tonnage was credited.

Yes, JANAC was not well received. I know there was at least one other list produced after the war that fell somewhat between the two. I had ready access to this particular table, and I think it shows the point.

If you'd like to ignore the tables, you can look at some other sources. I know I've read multiple times of task forces being reported with sightings of battleships, when in reality, there were only cruisers and destroyers present. Identification of targets with only quick looks through the periscope and out of date identification sources was simply not that accurate.

[TorpX]

The question of JANAC and IJN records reminds me of similer questions about German fighter plane production in WWII. The Germans claimed to have produced very large numbers of fighters, but when the losses, captures and such are added up, the numbers don't square. One author forwarded the theory, that planes sent back to the factory for repair, were counted as new production, and thus double or triple counted. Possibly, they were simply inflated because of political pressures.

The point I'm trying to make is JANAC was based largely on IJN records, and these records may not be accurate. Given the magnetude of their problems, it is easy to see why, keeping neat and tidy records, may not have been the highest priority.

[CapnScurvy]

With a new mod I'm about to release the Recognition Manual will have ship lengths added for every ship (see image below). I realize there are a lot of you that think the game uses accurate figures when giving mast height, ship length (no matter where you find the results), or draft depth etc. You're wrong. The game has a bunch of figures that could have been verified from the back of a cracker jack box.



These measurements mean nothing to a player who uses the automatic targeting method. The game happily calculates the targets position and speed (and why shouldn't it, the games the one that put the target in front of you in the first place!) and gives you a green light when its time to press the fire button.

Those of you who use manual targeting have to find range, speed, and Angle on Bow on your own to make a proper firing solution (or maneuver yourself soooooo close to the target, you can't miss). The point is the game didn't spend a lot of time putting in measurements that a manual targeting player could use. Nor, did it make the viewable game world correct to use any real world measurements. The Optical Targeting Correction mod will correct the game worlds view which was off by several degrees in width. In doing so, real world numbers may work as they should, I don't know, or care. The only factor I've every concerned myself about is what are the results of in-game play. If the games measurements read x amount high, x amount long and a correct range, speed or AoB can be attained with them, why do we need real world measurements added to a game that doesn't know how to use them correctly? As I said, the real world figures may work correctly with the optical changes to the game views after the OTC mod. What I've done is calibrated each height and length figure to provide as accurate a measurement as reasonably possible. The rest is up to the other factors in the game that make manual targeting the difficult process that it is (weather, lighting, detection, distance to target, movement of all factors involved).

[Rockin Robbins]

In other words, if the game is wrong about the length of the real ship, but uses that wrong length for in-game plotting and calculation, you'd better use the game's wrong number for calculations or you could miss your shot.

When in Rome do as the Romans do!

What kind of length errors does the recognition have compared to the in-game lengths? Is the percentage ever consequential? I'd think the masthead height errors would have much worse effects on shooting.

[CapnScurvy]

Originally Posted by Rockin Robbins

In other words, if the game is wrong about the length of the real ship, but uses that wrong length for in-game plotting and calculation, you'd better use the game's wrong number for calculations or you could miss your shot.

When in Rome do as the Romans do!

What kind of length errors does the recognition have compared to the in-game lengths? Is the percentage ever consequential? I'd think the masthead height errors would have much worse effects on shooting.

Double R, I don't know if the ship lengths found in the game are correct or not based on real world figures. I've never compared what the game lists as a measurement (length or height) to see if it matches its real world counter part. I've only based my measurements of these points within the game itself. In other words I let the game tell me it has a ship measured at a specific distance (range) I then check the math to see what the angle (giving length) and height of the point of reference should be at that game distance. Is the game distance truly a measurement of an actual yard, meter, nautical mile in real life? Who knows? The point is the game says "this" is called a yard, or a foot, or whatever, and "this" is what gets used for our calculations. I just compare the calculations and match the correct figures to them so the game reads an accurate measurement. I couldn't care less if it matches real world figures or not.

Take for instance the German Pocket Battleship with a game mast height of 47 meters. The corrected measurement of the mast height should be 37.8 meters following my correction method. This just under 30 feet of difference is what keeps a manual targeting player from getting a correct firing solution when trying to find range to target. Is the 37.8 meters of the mast head correct to real world figures? Again, I don't know or care, but 37.8 meters will give you correct range when using the Stadimeter or using the Telemeter division marks (when the correct optical view is enabled) for finding range!! To me, that's the important thing.

As you point out RR, the height reference point measurements are indeed critical for range finding. The length measurements are basically for figuring Angle on Bow. If you know the targets length at an abeam (perpendicular) view at a specific range, you can gain its AoB by comparing the difference in length when the ship is at an angle at that same distance. To help calculate this an Omnimeter was used, found here. To answer your question regarding the length measurements and are they off as much as the mast heights figures in-game? No, luckily they are just about right on!! Oh, I've done a bit of tweaking, but once the optical views are corrected, the length figure found in the .cfg files were really pretty good to what an accurate measurement needs to be. Surprising but true.

[Rockin Robbins]

And that begs the old question: are the game errors just plain sloppiness on the part of the devs or purposeful helter-skelter to make our lives more interesting?

After all, a 25% error in the mast height translates into a 25% error in range. A ship measured at 4000 yards could be at 3000 or 5000 yards (depending on whether the game masthead number is 25% too high or 25% too low), a deviation of 2000 yards.

Seems like the easiest way for that stadimeter to work would have been for it to grab the masthead height from the game's working parameters, not a separate and wrong table. That makes it seem to me that the errors are purposeful for some unknown purpose....something like that.

[razark]

Originally Posted by Rockin Robbins

That makes it seem to me that the errors are purposeful for some unknown purpose....something like that.

Perhaps an attempt to implement the uncertainty in target data?

[Rockin Robbins]

Well, then you just read the game data and multiply it by a randomly generated uncertainty, say between +-120%, for instance. Then you get a different error for every measurement. THAT would make sense. But a hardwired error is much more thought provoking.

[CapnScurvy]

Eh, I don't think the errors are a part of "the fog of war" many would like it to be in this game.

The truth is the darn game was released using the metric system of measurements!!!! What kind of an American simulation of WWII warfare brings a totally bogus system of measurement to the table?!? The authenticity of the SH3 game was having German speaking crewmen using only the metric system for measurements. It took modders to fix the game so we could use it over here on this side of the pond!! But that was ok with me, the authenticity was great with SH3. With SH4, authenticity went out the window to appease the game promoter (UBISoft) who wanted to make a quick buck on their return. To their credit, the devs posted the first patch only a month after the release adding the Imperial set, but the problems of having the game not correctly convert the measurements back to the metric system wasn't fixed until about patch 3 or 4.

If the devs thought they had a "fog of war" thing going for them with wrong mast height measurements why in the world did they change many of them with the 4th patch?! They didn't correct them, they just changed some of the figures. Why bother at all if the idea was to give some since of unreliability???

Nope, the errors are an oversight (there are a couple of ships that are right on the money with their mast heights), but way too few to give a manual targeting player an even chance at getting a firing solution right. Again, if it wasn't for the ability to stick your nose up the targets backside and pull the trigger you'd play hell in ever hitting a target with manual targeting.

[vanjast]

I made a list somewhere of the shiplengths.
I placed a sub and at 1nm placed each ship in turn, measured the scope angle, by rotating the scope. From this calced the ship length. I should have done the mast height as well, but didn't think of it.


I should redo this list..