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andqui · 07-15-11, 11:25 PM

Here's one way to do it. Keep in mind there might be other ways that would be better, depending on the situation:

1. Get a good GUI mod. I use MaGui Final here.
This has an AOB-finder wheel and an attack disk. Real Uboats did not have GPS installed and thus could not do most of the 20-step plotting techniques you see around. Instead, plotting targets is all about the relative position of your boat and the target. The tools in one of these will make this possible.

The attack disk is the main tool. The pdf here here is full of illustrated examples of the neat things it can do to make your job easier. The disk they use in the pdf is a tiny bit different than the one that comes with the above interface, but the principles are the same.

If by "intercept" you mean meeting a reported contact at the same place at the same time, then all you have to do is see the first two examples in the pdf. Follow the instructions, and turn the wheel nine times in the correct way, and you're good to go.

If by "intercept" you mean setting up an attack when you see a smudge of smoke on the horizon, read on. This is assuming that you're using the above MaGui and the tools in it.

1. You see a smudge of smoke on the horizon. After you get a bit closer, come to a full stop. Take note of the bearing of the target, and start the stopwatch. Watch the bearing change, and wait until the difference is at least 5 degrees from your first bearing. Then, record the new bearing, as well as the time elapsed. While the clock is still ticking, find the angle between the two bearings by subtraction; again, it should be at least 5 degrees.

2. Now you wait some more, until the same amount of time has elapsed. For example, if your second bearing was 4 minutes after the first, wait until the stopwatch shows 8 minutes. At this point, take a third bearing, and find the difference between that and the first bearing. You should now have two angles, that between the first and second and then between the first and third. Click on the navigator icon in the bottom right once, bringing up the avaliable orders. Then hold your mouse to the right side of the screen and you should see a wheel pop up. This is the AOB finder. Click, drag, and rotate the wheel so that the angle between the first and second bearings on the outside is lined up with the angle between the first and third bearings on the inside. Inside the little window at the top of the wheel, there is a number. This is the AOB of the target at the time of the first bearing. You're 75% done.

3. There are two buttons labelled "F" and "B" at the bottom middle, which bring up the front and back sides of the attack disk respectively. Open the front side. There are two things you can click and drag- the transparent pointer that contains two black boat outlines, and the inner circle. This part his hard to describe so bear with me. The outer scale is bearings from your boat- drag the pointer so that the black arrow at the tip points to your first recorded bearing. For example, if you first saw the target bearing 55, then drag the pointer until the black arrow points to the 55. Then, you simply turn the inner circle so that the AOB you found in step 2 lines up with the other black ship icon on the transparent pointer. The white silhouette points towards 0 AOB, the green numbers are starboard and the red numbers are port. Once you've done that, the target's course can be read on the inner set of numbers on the white scale. For example, if my boat is headed 39 degrees, and I see the target at bearing 141, with an AOB of 100 starboard, the target's course is around 258. See example 10 in the pdf if your confused- it's difficult to explain without pictures.

Getting the correct course is the hard part. Once you have that, you can use the attack disk to calculate all sorts of stuff, like speed, your heading for a perpendicular attack, what speed you should go to have the target pass X distance in front of you, etc. In the pdf, I've found that the most useful examples are numbers 1, 2, 9, 10, and 11. Example 10 is basically exactly what I wrote up in step 3, but described better. I strongly recommend you take the time to learn the attack disk- it will make things so much easier and faster, and you won't have to worry about unrealistically drawing right angles and tangent circles and whatnot on the nav map.

Of course, there are other methods. If you don't have the time to do the full stop three-bearind AOB check, you could simply try to turn on the same course and speed as the target until you're keeping him at a constant bearing (i.e. moving parallel to him at the same speed) for an estimate, and then refine your data as you come in. Most importantly, attack at a right angle to the target's course from as close as you can If you attack from 90 degrees with a torpedo gyro angle of zero, your range estimate can be off by a bit without affecting your accuracy because you end up with a right triangle, and the lead angle for the torpedo doesn't change with range, and the closer you are, the less time for your errors to affect your accuracy.

That's all I have the energy to write up right now. If you have any more questions just ask.

07-15-11, 11:25 PM	#2
andqui Soundman Join Date: Sep 2007 Posts: 149 Downloads: 195 Uploads: 0	Here's one way to do it. Keep in mind there might be other ways that would be better, depending on the situation: 1. Get a good GUI mod. I use MaGui Final here. This has an AOB-finder wheel and an attack disk. Real Uboats did not have GPS installed and thus could not do most of the 20-step plotting techniques you see around. Instead, plotting targets is all about the relative position of your boat and the target. The tools in one of these will make this possible. The attack disk is the main tool. The pdf here here is full of illustrated examples of the neat things it can do to make your job easier. The disk they use in the pdf is a tiny bit different than the one that comes with the above interface, but the principles are the same. If by "intercept" you mean meeting a reported contact at the same place at the same time, then all you have to do is see the first two examples in the pdf. Follow the instructions, and turn the wheel nine times in the correct way, and you're good to go. If by "intercept" you mean setting up an attack when you see a smudge of smoke on the horizon, read on. This is assuming that you're using the above MaGui and the tools in it. 1. You see a smudge of smoke on the horizon. After you get a bit closer, come to a full stop. Take note of the bearing of the target, and start the stopwatch. Watch the bearing change, and wait until the difference is at least 5 degrees from your first bearing. Then, record the new bearing, as well as the time elapsed. While the clock is still ticking, find the angle between the two bearings by subtraction; again, it should be at least 5 degrees. 2. Now you wait some more, until the same amount of time has elapsed. For example, if your second bearing was 4 minutes after the first, wait until the stopwatch shows 8 minutes. At this point, take a third bearing, and find the difference between that and the first bearing. You should now have two angles, that between the first and second and then between the first and third. Click on the navigator icon in the bottom right once, bringing up the avaliable orders. Then hold your mouse to the right side of the screen and you should see a wheel pop up. This is the AOB finder. Click, drag, and rotate the wheel so that the angle between the first and second bearings on the outside is lined up with the angle between the first and third bearings on the inside. Inside the little window at the top of the wheel, there is a number. This is the AOB of the target at the time of the first bearing. You're 75% done. 3. There are two buttons labelled "F" and "B" at the bottom middle, which bring up the front and back sides of the attack disk respectively. Open the front side. There are two things you can click and drag- the transparent pointer that contains two black boat outlines, and the inner circle. This part his hard to describe so bear with me. The outer scale is bearings from your boat- drag the pointer so that the black arrow at the tip points to your first recorded bearing. For example, if you first saw the target bearing 55, then drag the pointer until the black arrow points to the 55. Then, you simply turn the inner circle so that the AOB you found in step 2 lines up with the other black ship icon on the transparent pointer. The white silhouette points towards 0 AOB, the green numbers are starboard and the red numbers are port. Once you've done that, the target's course can be read on the inner set of numbers on the white scale. For example, if my boat is headed 39 degrees, and I see the target at bearing 141, with an AOB of 100 starboard, the target's course is around 258. See example 10 in the pdf if your confused- it's difficult to explain without pictures. Getting the correct course is the hard part. Once you have that, you can use the attack disk to calculate all sorts of stuff, like speed, your heading for a perpendicular attack, what speed you should go to have the target pass X distance in front of you, etc. In the pdf, I've found that the most useful examples are numbers 1, 2, 9, 10, and 11. Example 10 is basically exactly what I wrote up in step 3, but described better. I strongly recommend you take the time to learn the attack disk- it will make things so much easier and faster, and you won't have to worry about unrealistically drawing right angles and tangent circles and whatnot on the nav map. Of course, there are other methods. If you don't have the time to do the full stop three-bearind AOB check, you could simply try to turn on the same course and speed as the target until you're keeping him at a constant bearing (i.e. moving parallel to him at the same speed) for an estimate, and then refine your data as you come in. Most importantly, attack at a right angle to the target's course from as close as you can If you attack from 90 degrees with a torpedo gyro angle of zero, your range estimate can be off by a bit without affecting your accuracy because you end up with a right triangle, and the lead angle for the torpedo doesn't change with range, and the closer you are, the less time for your errors to affect your accuracy. That's all I have the energy to write up right now. If you have any more questions just ask.