@peabody


Yeah, the stadimeter portion of the TDC actually supplies 2 pieces of data. One is the range and the other is the relative bearing. If you click the send button without using the stadimeter, you be only putting in the bearing.

Forget trying to explain what's going on while in the game. Save it until you edit ... then dub it all in.

looking for tools to do that
 

Remember, just the recording was impossible before, so I'm below grass level looking at the roots. What's a good tool for dubbing sound on a video track?

I had never heard of the Dick O'Kane method (although I had indeed heard of him!) and it didn't make a lot of sense until aaron's excellent explanation.

I won't have access to my gaming PC for a week or so though, so I can't test it out. Trying to work out the problem in my head, some questions remain.

Apparently, I just input the target's speed and the theoretical AOB of 90º just to find out the lead angle for a perfect perpendicular hit, then input the correct AOB, move the periscope that number of degrees towards the target's approach course and fire at different spots of the ship as it goes by the vertical mark. So far, so good.

Still, for the constant bearing formula to apply, my fleet boat would have to be moving, correct? Does this method work from a static boat?

Also, technically for the formula to work completely and the bearing to remain truly constant, there would have to be a perfect marriage between the target's speed and the sub's speed, which is obviously not always the case. I assume the inaccuracy is negligible for normal firing ranges (600 to 1200 yards in my case)?

Also, did Dick O'Kane actually invent or use this method? Where's the reference? :D

Man, I love this forum. Thanks everyone for your endless wisdom.

The formula is independant of sub's speed. The only thing a moving sub will do is increase or decrease the distance to the target.* And, as you already know, distance is not an important factor in the attack geometry.

* Granted, it might impart a little extra momentum to the torpedo but not enough to make any appreciable difference.

Hello! First feeble attempt at a video.
 

Dick O'Kane had two books, "Clear the Bridge!" about the USS Tang and "Wahoo." I have not read the books but while developing U-Boat techniques for the fleet boat, aaronblood told me about passages in both books where O'Kane mentioned shutting down the PK and shooting as the target passed the mark. That's about as specific as O'Kane gets, but we were searching for an appropriate name for our technique and as a tribute to O'Kane and seeing that he COULD have used something very close, we decided to call it the Dick O'Kane method. His original idea that I approved of.

Note that the constant bearing isn't from the POV of the submarine, but the POV of the torpedo! As the torpedo speeds toward the target, the bearing of the target from the torpedo does not change until BOOM!

Well, here's a good setup with a double-blown attack. What did I do wrong here? First, I waited too long while I ran my mouth to raise the periscope. Then by the time I raised it the last half of the ship was passing my chosen shoot bearing. So I changed the aiming point all the way up to about 15º AFTER zero, that's 30º after I planned to shoot and shot five anyway. Then after carefully explaining that you have to push the send range/bearing and AoB send buttons twice, I only pushed it once.:cry: See what happens with this blown attack. Hope it gives you a lot of confidence.

Blown Dick O'Kane tutorial attack, courtesy of your source of "endless wisdom" and fumble fingers: Rockin Robbins. Yeah, "Endless Wisdom" blew the attack! How do you like THEM apples? Ha!:rotfl:

Yes, it works from a stationary position. No, for the bearing to remain constant the two objects DO NOT have to be going the same speed.

You're not calculating the intercept course for the sub to impact the target... it's the torpedos constant speed! Your sub can be sitting perfectly still or creeping toward the target on a perpendicular path to the target's course. If my sub was moving closer to the targets course, all I would be doing is shortening the distance to the impact point. ...and we know distance is irrelevent in the calculation.

In my plot example above the subs heading is perpendicular to the targets path, and could be moving or stationary. The plotted intercepts in that case relate to the constant speed of the Mk1 torpedo moving at 18kts.

In the Wahoo book, O'kane was Mush Morton's XO. It was while he served under Morton that he developed the tactic of holding the aiming wire constant and firing while the target points of interest passed the aiming wire.

Here's a link to the book: http://www.submarinebooks.com/WahooHB.htm
I found it at my local library and would have to re-check it out to find the exact page references.

In the Tang book O'Kane also mentions that he continues to use his method of holding the aiming wire constant... but it doesn't go into too much detail beyond that.

Neither book gives me the impression that O'kane completely ignored the PK. On the contrary, I was under the impression that he made deadly use of it. In fact he was constantly practicing and drilling his crew with a model ship on a lazy susan to help better estimate AoB. I believe he entered the data in the PK, watched how the ship tracked against his estimated AoB, made slight adjustments based on VERY BRIEF peeks with the scope, and when it came time to fire he held the wire and fired while points of interest passed.

It's the notion of momentarily freezing the aiming wire that deserves the nod to O'kane.

Hmmmm...

Thanks *a bunch* for the explanations!

After reading your amazing description and looking at the Mobo image again, I believe I get it, and the method is simply genius, not to mention a tad simpler than most other methods and, if your plot to the target is good enough, more accurate, specially since the stadimeter apparently hates my guts.

Of course, it calls for a really good speed estimate, but on the other hand it makes aiming at different parts of the target more intuitive than the usual method of resorting to the spread angle dial. I also assume this would be extremely useful for convoy attacks, since all ships in a convoy supposedly hold the same course and speed...

If you're lucky, you might even fire at a distant ship in a convoy first and at a closer one second, and hit both roughly at the same time, minimizing the chance of evasion.

I'll get both books. So far all I've read about O'Kane was in Beach's book, and I already had the impression that he was a wicked dude, but this is way too much! :D

Yes, I readed his books and a lot more of stuff and I think that the PK was used by him a lot for the tracking party. However, once the target data were confirmed and the attack position chosen, he switched it off in favour of a stuck firing solution with the fixed wire. Which incidentally is also what the germans most usually did :D Interesting to see how in opposite sides of the world they came to the same method :hmm:

Great video RR!! :up:

Ah Ha! One needs to send data to the TDC twice, I was only clicking once...

Thanks!

After doodling around in my whiteboard this magical thing called Richard O'Kane method, I saw that it would work brilliantly with Sugar Boats as well. I was using the Kulick method with sugar boats to some success, but this would work a tad better!

It's really a nifty solution, since the stadimeter is pretty inaccurate most of the time (at least in my hands!) and spreading torpedoes along a hull using spread angle is a pain.

While I wait till I have time to resurrect my gaming PC, I'll purchase the expansion so I'm all set for TDC action by the weekend.

I got the same impression. Since neither O'Kane nor Morton had the advantage of "automatic map updates" to determine target speed, they probably inserted a WAG into the TDC, then watched to see how closely their estimate fit the ongoing geomety.

If I remember correctly, O'Kane even made mention of it in one of his books ... comparing each observation against how the picture progressed via PK. Once he was reasonably certain of the target's speed, he reverted to using 90-degree attack geometry.

Can you believe I messed up the attack at the end by pressing the send button only once? :damn:

@munchausen: I think you've it on it perfectly there! O'Kane was considered a TDC/PK wizard, who knew his equipment totally. Using the PK to refine speed measurements is exactly what he would do. However, I think he would also have been able to measure speed precisely with two radar fixes. Then the PK would just verify that the target had not changed speed or course. Then he would turn off the PK at the end of the attack to shoot as they pass the wire. All this is just speculation but it is educated speculation, knowing that O'Kane used every tool at his disposal to avoid misses. He HATED to waste a precious torpedo.

Even though you blew that attack, it was a great video... really gives a straight ahead approach to how it should be done and as long as we aren't talking to ourselves while on our attack runs we shouldn't foul it up lol..


Thanks very much for the vid, can't wait to see another without the oops!!

:cool: Indeed. It was an "old" torpedo that literally bit him in the backside. He had a feeling it needed servicing but, in the heat of battle, decided not to "waste" the opportunity.