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Originally Posted by Joe S
I assume you got the Dick o'Kane method from one of his books, both of which I have read , but not recently. If you did get the method from his books, can you tell me which one and approx where so I can re-read that section?
You probably already know this but maybe some people do not: once you establish the amount of lead in degrees for a given target speed, that angle of lead is good no matter what the range. In the example you gave in the above referenced post, a lead of 9 deg was used based on the speed of the target. If you have an accurate target speed calculation, all you have to do is aim the torpedoes the given amount of degrees ahead of your desired point of impact and you should get hits.
I believe your method is sound, but have not tried it. After I try it I may have a few more questions. Thanks for your help. Joe S
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In his books, O'Kane tells how he dispenses with the necessity of knowing the precise range and turns off the position keeper during some attacks. With the help of aaronblood and gutted, we reasoned out that the most likely type of attack which met those characteristics was a modified Fast-90 attack from the U-Boats. Gutted had made a chart showing the lead angles for German torpedoes, which he modified for fast and slow Mark 14's.
For the fast-90 attack to work, you look up the lead angle for the target speed. First you set the torpedo to run up the zero bearing. Then you point the periscope at that angle before 0º, 360 minus the angle for targets moving left to right and the angle for targets moving right to left. As juicy parts of the ship cross the crosshairs, shoot.
Then it was left to me to figure out how to use the blasted thing. At the time we were all under the impression (the manual said so) that in order to work the stadimeter the periscope had to be locked on a target. This was bad. So I loaded up WernerSobe's Natural Sinking Mechanics test mission and went to work. After much trial and terror, I found that the periscope didn't have to be locked on anything to send a bearing. You didn't even have to use the stadimeter when you sent a bearing. You could set the torp track across empty water by pointing the periscope at a bearing and pressing the send range/bearing button. Then you sent a bearing without a range. Perfect!
So I set up for a fast-90 with gutted's chart. 9 knots = 11º, blah, blah, blah, shoot! And the torpedo passed well in front of the target. @#$@#$%@#$$!!!! I analyzed the attack and found that I had used the column for slow torpedoes on a fast torpedo. And I realized that you would have to have a separate column for Mark 18s and cuties and... This is so complicated nobody will be able to hit anything. What now?
There was only one option: find a way to toss gutted's chart. And then I realized that we already had a chart that picked its own column: the TDC! As long as the PK was off, all the TDC did was calculate the lead angle for a target moving at a certain speed for a selected torpedo. So the Dick O'Kane technique was born. No more chart!
Now, you measure the speed of the target and enter it into the TDC. Doesn't matter which direction it's moving in, you set that with the AoB. Now you set the AoB for 90º minus the number of degrees from zero you're going to shoot! If you're going to shoot at 350, your AoB will be 90 - 10 = 80º. Your target is moving left to right so your AoB will be starboard (right) 80º. Lastly we'll select a forward torpedo tube, point the periscope at 350º and press the send range/bearing button. OK, now maybe 15 minutes before you shoot we're all set up and all we have to do is wait. You can look all around with the scope and not mess up the shot.
OK, here comes the boat. You don't even have to keep the scope up, just look at the sonar bearing and take a peek now and then to make sure he hasn't changed course. You're a hole in the water here. When the sonar bearing gets to about 340, raise the scope and point it at 350. Open up a couple of tubes. As the front crane passes the crosshairs, shoot. Cycle to the second tube and shoot it as the aft crane is in the crosshairs. Two booms will follow and the ship goes down. You had the whole shot set up 15 minutes before the ship got there!
Is that as easy as it gets? I think so.
