O'Kane and AOB

[Doenitz2008]

Hi,

Been trying to master O'Kane and have a question about AOB.

Scenario : a merchant is approaching from my right. I have set my course perpendicular to his, and have decided to fire as he crosses the 10 degree bearing mark. My analysis is thus the AOB when I fire would be 100 degrees. I assumed this because if I were standing on his deck and siting the sub, thats what the subs bearing would be. Or am I doing this *** backwards??

Thanks for any tips

[Platapus]

Setting up a fast 90 like you described, you would set the AOB indicator to 80 degrees (assuming fast torpedo setting) Port

An AoB of 100 would mean that the ship had already "crossed the line"

[razark]

If you're closer to his bow, the AoB is less than 90 degrees. If you're closer to his stern, the AoB is greater than 90 degrees.


If the ship is crossing from your right to left, and you are on a 90 degree intercept to his track:
When he is at 20 degrees, AoB is 70 degrees Port. When he is at a 10 degree bearing, AoB is 80 degrees Port. At a bearing of 350 degrees (already crossed your bow), the AoB is 100 degrees Port.

If the ship is crossing from your left to right, and you are on a 90 degree intercept to his track:
When he is at 340 degrees, AoB is 70 degrees Starboard. When he is at a 350 degree bearing, AoB is 80 degrees Starboard. At a bearing of 10 degrees (already crossed your bow), the AoB is 100 degrees Starboard.


Edit:
It really helps if you have the sort of mind that can easily visualize the geometry of the problem. Some people just don't do that easily as others. It may help if you grab a pencil and paper and draw it out, or at least draw it on your nav map.

[Doenitz2008]

Made it crystal clear. I now expect to have 100% hit rate ....:rotfl2:

Or, well, at least to sink more tonnage :)

[I'm goin' down]

They have it right. O'Kane works like clockwork and is very accurate. Merchant firing point should be at an Aob of 80 degrees.

If you want to use the O'Kane theory at a variety of angles, download and learn how to use gutted's Solution Solver. It will calculate the lead angle for any Aob when you input the target's speed and course, and will permit you to calculte the correct heading for your boat if you choose to line up for a shot with an Aob of 90 degrees and give the lead angle for that shot as well.

Some tips re O'Kane if your initial shots miss:

Often misses shots occur because the target changed speeds after your initial speed calculation. If you take a speed reading when the target is ten miles away, the odds are greater that its speed may change in the interim. If the target spots your boat it may change speeds. If the target was on a straight heading initially, but begins to weave in and out, that is a clue that it may moving at a slower speed, and vice-versa.

If you don't get the 90 degrees set up correct, the Aob will not be +/- 90 degrees at torpedoe impact, so think about releasing your torpedoes towards or in front of the bow of the target if it is on a heading significantly less than at a 90 degree Aob, or release them closer or behind its stern if it will cross the firing firing point at an Aob significantly greater than 90 degrees.

Also, if you think the target has changed speeds (e.g, you check the Attack Map and see that your fired torpedoes will likely miss the target), do a quick, best judgment adjustment to the speed dial, click the stadimeter twice to reset the lead angle, and fire a couple of torpedoes at the target is pulling away. I have had luck with this technique.

I have used O'Kane so much, it is getting boring. So try using O'Kane with aft tubes. Getting your boat to line up at a 90 degree angle in reverse is a little tougher. If you miss an aft shot, check and make sure you did not fall asleep and fire your forward torpedoes, which I did yesterday. Otherwise the O'Kane principles apply.

[Bilge_Rat]

AOB can be very hard to judge visually. If you have plotted the course of the target on the map and you know its general direction, you can also just set the AOB in the TDC so that the target's course as shown on the TDC matches with your solution.

[I'm goin' down]

AOB can be very hard to judge visually. If you have plotted the course of the target on the map and you know its general direction, you can also just set the AOB in the TDC so that the target's course as shown on the TDC matches with your solution.

I do not disagree with your statement. However, I believe that it will only work if you have activated the Easy Aob mod.

Also, you can practice on visually setting Aob by working with gutted's Solution Solver program. (I have not done this, but gutted promoted it when the program was introduced.)

[Bilge_Rat]

I do not disagree with your statement. However, I believe that it will only work if you have activated the Easy Aob mod.



no, the stock TDC works like this also. I always map out the range and course of the target on the map. I find it much easier to work out a solution that way.

Say you know the target has a course of 45 degress (NE), you can turn the AOB dial until the upper dial of the TDC shows the target heading to a course of 45 as shown on the inner part of the dial. You then know you have the correct AOB inputed.

[CDR Resser]

Stock TDC works great for O'Kane's method as described in Clear the Bridge and Wahoo. All you must do is hold the bearing constant in the TDC for each individual impact point and torpedo. It really is relatively simple in that once you have a solution, you pick your impact points on the target ship, lead each impact point with the reticle, turn off the target following feature, which holds the bearing constant, and firing individual torpedoes as your point of impact crosses the reticle. It requires a lot of quick button pushing and I usually try to update my setup between each shot. It does work and I have been shooting with this method since I started playing with SH4. Best of luck.

Respectfully Submitted;
CDR Resser

[gutted]

AOB can be very hard to judge visually

Just match what you see in the scope on the AOB entry dial. Dont even have to look at the numbers.

Pretty easy if you ask me.

[Bilge_Rat]

Just match what you see in the scope on the AOB entry dial. Dont even have to look at the numbers.

Pretty easy if you ask me.

"AOB entry dial" from your mod? or the stock one in the TDC.

if stock, lets assume a freighter is heading towards you at true AOB 50. How can you estimate from visual sighting if his AOB is 40-50 or 60? Depending on its speed and range, a 10 degree AOB error will result in a miss.

if on the other hand, you determine range from stadimeter and visual estimation, plot the positions on a map and determine course, you dont need to estimate AOB. inputting the correct course will give you the correct AOB.

[gutted]

A 10 degree error is perfectly acceptable if you are firing from an ideal range & position.

But like i said, dont try to determine the actual AOB, just orient the picture of the ship in the AOB dial to what the ship looks like in the scope and you are good to go.

You dont need .001 precision. Nor do you really need to do any map plotting.

Input an AOB visually. Take note of the resulting target course by looking at the TDC dials on the left. Now when you do your two stadimeter readings for speed, cross check the course it gives you against that. If they are close, then the speed estimate is probably good. Adjust the AOB dial if necessary to put it on the exact course from the speed estimate.

It's a good idea to wait till minimal gyro to shoot so that any range errors are minimized.

Using the technique above, you can fire from any angle without plotting a single thing with good accuracy.