I hope at least a few people have been able to make some use of this. In order to make the calculations less objectionable and time consuming, I've come up with a program that will crunch the numbers and display the results in a pleasing way. (30 minutes to do the math and 30 hours to get it to display right, lol.)

I know Gamefront and others have had their issues and not everyone can access these sites. Does anyone have any advice about how/where I could upload this for public use?

It will be less than 3Mb. However, I have in mind some projects afterwards that I would like to offer. They would probably be of similar size. Also, it might be necessary for me to make adjustments or improvements.

I'm glad it is of some value. It took some time for me to get the diagrams squared away, but I knew that outlining the method without some decent diagrams would only lead to confusion. It is very hard to learn anything about geometry and trig without drawing it out.

On the "Downloads" main page you'll find the link to PM Neil directly regarding getting access to upload your mod(s). Once done and approved, you'll be able to add as many as you like, or edit an existing one anytime.

OK. I've PM'd Neal and while we're waiting to get word back, I'll give you all a peek:





http://i1130.photobucket.com/albums/...ps15fbb263.jpg



So there is no confusion; this is not a mod, but rather a utility to calculate a firing solution using the method outlined at the beginning of the thread. It should work on any Windows machine. We'll have to see about Win. 7 and Win. 8, though.




Here are a few features:

• • has resizable window
  • can change display font
  • can use yards or meters
  • can calculate stern tube solution
  • also calculates collision course speed

It turns out, it is only about 1mb when compressed. Does anyone know if something like this can be sent by email or PM?

Well, Neal has generously OK'd the uploading and I've got it all squared away. (I think it's ready, anyway.)

I haven't used MoBo, but I think that is intended to fulfill a different purpose.



This program will allow the user to manually calculate a zero-gyro angle firing solution, with a minimum of fuss. It uses the equations that I posted at the beginning of the thread. I have incorporated some changes and additions to make the process easier, however. I coded the angle inputs so the user can enter the relative target bearing 'as is'; there is no need to re-orient the angle. Likewise, there is no need to use a negative value for the sub speed when making a stern shot. Output angles are properly oriented and times are displayed in minutes and seconds. Also, one can easily change from yards to meters; so it is Kriegsmarine friendly. :)

The most difficult element I had to deal with (besides all the intricate never ending display changes), was putting in a series of logic checks to reject any sets of data that didn't allow a solution. It is probably not apparent why this would be needed, but I decided that it would be a substantial shortcoming if it were left undone. For example, if you are closing the target ship's track, bow on you can calculate the solution and it will give you the right answers. No sweat, right? But, at least in some cases, you could enter the same data and hit the "stern" button and get a false solution. Not good. Normally, this would be obvious from the plot, but if you weren't making the plot or were in a hectic and confused situation you might take it at face value. This bothered me, so I put in code which (I think) will catch all of these cases. One limitation remains from the original equations; you must still cross the target's track before you compute a solution for a stern shot. You can, of course, extrapolate your plot and compute a solution that way, but the program itself can't do it. I was going to put this capability in, but it would require another branch of code, and I decided to "keep it simple".

I added auxiliary calculations for collision course speed and optimum track angle. I had reservations about these. They aren't really required, but no extra data input is required and it wasn't difficult to add them. I think it is better to have capability in one utility, than maybe have to use another item/device.


I will probably present an example or two of it's use when I have more time, but it is fairly simple as long as you understand the definitions of track angle, etc., etc.


It can be found in the Utilities section of SubSim Downloads:

http://www.subsim.com/radioroom/down...o=file&id=3978

OK, no comments yet. I'm not sure whether that's good or bad.

In case anyone is having trouble with this, or readers are still a little unclear about AFS I, I've posted some examples, screen shots and explanations.

Here goes!


Target Track is in red
Sub Track is blue
Torpedo Track is orange (pink?)
bearing lines in black
angles in Gray

Case 1:

Target ship is on a closing track and will cross in front of Sub. At U0, Sub makes final observation before computing firing solution for BOW shot. Note in particular the Target bearing and Track angle. The bearing is obvious, but be careful about the Track angle. These two angles are all you have to worry about. The AoB is shown here only for reference, you don't use it in this method.

At U1, Sub launches torpedo, Target is at T1. Torpedo hits Target at T2.

http://i1130.photobucket.com/albums/...ps93d7facd.png





Here is the corresponding firing solution:



http://i1130.photobucket.com/albums/...psf16be767.png





Case 2:

Below is another BOW shot set-up. The main reason I am using this as an example is that this shows the Target is crossing from the opposite side and the Track angle is negative. This is important because the Track angle format is -180 to +180. If you use the wrong sign, you will not get the correct solution. Either you will get an error or wrong numbers. The program is designed to reject such cases.



http://i1130.photobucket.com/albums/...psc5478baa.png



And the solution:



http://i1130.photobucket.com/albums/...ps1c96b05e.png



Case 3, below:

Set-up for a STERN shot. I am assuming here that there is no option for a BOW shot for some reason. The Sub will cross in front of the Target ship, but has not done so, yet. There is nothing wrong with the set-up per se, only that the program wasn't designed to due this math.



http://i1130.photobucket.com/albums/...ps85472d86.png



And the screenie:



http://i1130.photobucket.com/albums/...ps9cbc4d66.png



Case 4, below:

This is the 3rd case after the Sub has crossed the Target's Track. Now the firing solution can be computed. Note how the geometry has changed.



http://i1130.photobucket.com/albums/...ps157dac8b.png



And the computed solution:


http://i1130.photobucket.com/albums/...psbe5e68e0.png




The computed information on the left, the optimum track angle and the collision course speed are not necessary, but I included them for reference since no additional data is required. The program actually uses the CCS to check if a solution is possible. The OTA is only for reference.

The program will not compute solutions for 0 or 180 degree Track/Bearing angles as this creates a divide by zero problem.


I would encourage people to get some scratch paper and sketch out a few set-ups just to see how it works and learn it. You don't have to go on patrol to do this.

Any feedback would be welcome. I am especially interested to hear what people like or dislike about the display. This is what I spent most of my time on and what proved to be most difficult.

TorpX