I'm sorry, your message doesn't make much sense. From what I understand of it, it seems I already did just that. With an example ship of 95 yards length. If your ship happens to be 95 meters then it's the same.

Another thing that bears explanation is the reason that Dick O'Kane chose the stern/MOT/bow order of his spread instead of just shooting bow/MOT/stern as the target crossed the wire.

When you shoot bow/MOT/stern as I show in the Dick O'Kane tutorials, all three torpedoes follow the same track to the target, following in each other's wakes. This is called a longitudinal spread. There's nothing wrong with that, and it works well.

Until the target sees the torpedoes! Then a course change may allow him to avoid one of the torpedoes. Since they all follow the same path, avoiding one is avoiding them all.

This becomes critically important when firing from ahead of the target, as in the John P Comwell method. The easy fix for the target is to turn into the torpedoes and let them pass harmlessly to port. Try it in smooth water in the daytime. They'll avoid just about every time! You'll see the target turn into the torpedoes if they are approaching from forward of the bow and turn away if they approach from aft of the bow.

BUT if you instead shoot stern/MOT/bow, you're going to have to do some extra work. But that order results in the most divergent of torpedo paths. No longer do they follow each other in a straight line, but each takes its own path to the target and when shot in this order, stern/MOT/bow, their paths are separated to the maximum extent possible.

That means that avoiding one torpedo does not avoid the other two. The solution is MUCH more tolerant to possible reaction on the part of the target and your odds of a hit are much higher.

Using any method in smooth water during daylight it is critical that you shoot from such a range that the target cannot avoid your shots if they see the torpedoes approaching. That means that 1000 yards is the maximum I would attempt in those conditions, and my ideal would be 500 to 700 yards, just long enough for the torpedoes to arm. At that distance the target can gawk at the torpedoes and do anything he wants. He's dead meat.

My bad mate!!:salute:

Dogfish is catching up on his homework
 

Dogfish, I stumbled upon your post yesterday. The posts you refer to are from November 29, 2008! A mere 25+ months ago. No one can say you failed to read the thread.

Order of target points
 

Hello, everyone! I'm new here and have been playing SH4 for a few weeks. I played SH1 about 13 years ago and now remember why I played it so much.

I'm just now reading O'Kane's "Wahoo" and he described his attack method, which he and Morton developed together, as giving the enemy ship almost nowhere to go regardless of his maneuvering after seeing the incoming torpedoes. In reference to RR's recent post, RR explained the reasons for O'Kane's order of the torpedo/target points perfectly. O'Kane worked from middle to stern to bow, in that order, on most of the attacks he described in the book.

What I haven't been able to figure out quite well is how he moved his aiming point. I'm guessing he set up the whole attack for the first torpedo and held this bearing until the middle of the ship crossed the periscope hair, then moved the periscope to some point ahead of the first one, reset it in the TDC, then waited for the stern to cross that line, then moved ahead again to a third bearing, reset it in the TDC, and waited for the bow to cross the hair then. As RR says, that will result in three very divergent tracks, which give the enemy skipper no options that will avoid all the shots. O'Kane described pulling this kind of attack, and having all three shots out of the tubes in about 20-30 seconds. That seems to be enough time to reset new bearings for each of the target points on the ship, but that's just a guess.

The other thing he mentioned is that Morton favored a 120 degree setup with the above procedure, and that seems to be the key in the "no avoiding options" factor on this method, but I haven't been able to picture in my mind exactly what he means by that. I'm guessing he means firing from 30 degrees abaft the midships point on the enemy target, but i'm not sure about that or how that would be better than a straight 90 degree setup.

And if I understand how this method uses the technology onboard, the TDC is still giving gyro angles to the torpedoes that factor in speed and angle on the bow of the target but, since the bearing is fixed, the PK is not updating the position of the ship. In effect, it's tricking the PK by saying that the target is at the shooting bearing before it's actually arrived there and just holding off on the shoot until it does arrive. True?

And, finally, I saw someone earlier in this post someone talk about calculating AoB or eyeballing it. O'Kane was an expert at eyeballing it (as has been mentioned in other threads here), and doing so would be a good back-check that the visual, plot, and TDC data are all matching before shooting, meaning all the data input so far has led to an accurate solution inside the boat that matches what the skipper is seeing on the surface. I've not read anywhere of a plotted AoB being used as credible attack data. I think they were always eyeballed by the attack officer.

The amount of info on here is terrific and as added an enourmous amount to my enjoyment of the game. Thanks to everyone here for that!

Just .02 worth from a noob.

pitts2112
 

Welcome aboard skipper. You will be well served here. Yours was a very thoughtful, well articulated post. I am looking forward to the responses.

Welcome aboard Pitts! Well, as I understand it, O'Kane set up the shot and then fired when the juicy parts 'passed the wire' e.g. the aiming mark on the periscope, so that would suggest Bow, MOT, Stern as the firing order. I don't remember him setting up for a different firing order. Have you got a page number for him doing that? It's been a while since I read either of those books.

120 degrees of what though? 120 degree torpedo track angle? That would be fired from behind yes.

Right, imagine everything is entered for the current target and it's all checked out with subsequent observations and the PK is running. What you do is move the periscope forward of the target and then tell the TDC operator to 'match' bearing. The TDC operator then moves the target bearing forward to match your aiming point. What this does is to advance the theorhetical TDC target along the ship's track, to a point where it would actuallt be if it had suddenly leapt forward along its own track. This makes the TDC adjust the range and the AoB of thetheorhetical target to what it should be for the target at that point. Now the TDC operator has to very carefully turn the target ship bearing input crank backwards so that the relative target bearing shown on the TDC does not move.

That's the key part really. What the TDC operated in this way what it is doing is continuously calculating the gyro angle for a torpedo to hit the spot at which the target's track and the aiming bearing intercept (if that spot was moving at the target's speed). This point moves continuously forward along the target's track, but less fast than the target moves along it. As you are calculating the intercept point between your periscope bearing and the track, when the part of the ship you want to hit arrives there as well, then you just fire a torpedo and it will hit that part of the ship. As the TDC is still running, it takes care of the range changes. The AoB will stay the same and as the speed is all entered in, the angle solver will provide the correct amount of advance to hit a moving target.

pitts2112
 

also see posts 18-20, supra, by Nisgeis.

Nisgeis developed the radar fix mod this year. You might want to check it out after you have satisfied your curiosity with the O'Kane method.

Reading for detail
 

Thanks for the welcome, guys!

Nisgeis, you've caused me to go back into "Wahoo" and read for more detail. What I've discovered is that O'Kane did seem to have favored working stern to bow, though not always, and seldom did he shoot from bow to stern. This implies he was shifting his point of aim for each shot. And that makes sense, now that I think about it because if he worked from bow to stern, and simply held the bearing fixed for all shots, then the torpedoes would have all gone down the same track, giving no spread at all.

He does also make mention of the TDC operator "holding the bearing steady" which implies he was doing something to the TDC, maybe that it wouldn't do on it's own, or had shut off the PK. I don't know how the TDC operated well enough to truly understand that passage, though.

To whit:
Page 137, the attack in Wewak harbor, their first attack on a destroyer was stern, midships, bow, in that order. The next attack was the famous "down the throat" shot on another destroyer, so doesn't really apply (but, man, what balls those guys had!).

Page 148, they attacked two freighters, working both from aft forward to hit their masts (main first, foremast second).

Page 261, he again worked from stern forward on another freighter with two torpedoes.

Page 263, this must be the one that stuck out in my mind, because he distinctly worked back and forth, aiming for midships first, mainmast, then foremast, so starting in the middle, shifting point of aim aft, the shifting again the length of the ship to hit foward.

Page 157, a freighter and tanker, again working from aft forward with three torpedoes at stern, midships, and bow on the first target, the tanker. On the second tanker, he again worked aft forward with two torpedoes at midships and bow.

Those are all I looked up but are certainly not all the kills O'Kane and Morton made in Wahoo. Looking them up was actually pretty easy. All you have to do is scan the pages for the words "Anytime, Dick", as those were Morton's words to O'Kane, on every attack, that is was OK to shoot.

And now that I think about it, Morton always seemed to give O'Kane the green light to fire when O'Kane announced a 90 degree AoB, which means all the torpedoes would be chasing the ship slightly from behind. This is possibly how he acheived the 120 degree attack, which had the added benefit of not putting a 90 degree hit on the exploder so he got fewer duds (?).

I really wish these guys were still around to answer questions as to what they were really doing and why it worked so well. Fascinating stuff, this.

Cheers!

Yeah you're right. I think it's been too long since I read it - perhaps time to read it again. To shoot multiple times he just selects a point ahead of his aiming point, places the scope wire there, matches the bearing on the TDC and then fires when the desired part of the ship touches the wire. It's a minimal amount of effort as the TDC does all the work for you.

The PK wouldn't have been shut off, as that's a prime piece of technology there. The key is holding the bearing steady, which means the TDC operator winding it back at the same rate that it advances to hold it steady at the same angle that the periscope was pointed at. Then you know your shot will hit the part the wire is touching (assuming your solution is correct).

Yes, actually, as Nisgeis and I had quite a long conversation about quite awhile back, there is an optimal torpedo track angle for maximum error absorption of observational errors and which makes it less possible for the target to maneuver away. He shot me this graph and asked what it means.

http://i196.photobucket.com/albums/a...reenshot77.jpg

It shows the optimal torpedo track angle for a fast Mark 14. You see that angle increases slightly with target speed, but nowhere is it close to 120º. The most it gets to is just over 110º.

Anyway, we were trying to figure out just what the crazy thing was trying to tell us. After all, we can't enter TTA into the TDC and do anything with it. So I reverse engineered the whole thing and after all the fancy math, curses and the smoke cleared, I was left with one simple rule of thumb that explained the entire graph.

Fire when the AoB is 90. Then the TDC automatically calculates the lead angle, which is (of course) larger as the target speed is faster, yielding the TTAs in the stupid incomprehensible graph!

The truth is, you don't have to even think about torpedo track angle. It is simply a product of firing at the correct time. Why couldn't the US military have explained it that way?:D

Note that the chart specifies a zero gyro angle. In practice, anything under 20º is considered straight fire and will have no consequences, so you don't need to worry too much about that. If you attack at 90º to the target track as in the Dick O'Kane method, you're close enough for horseshoes, hand grenades and thermonuclear devices. If you just like worrying the process to death, you could attack from 110º.

He did! And in the entire book, the TDC he used was to generate a range and bearing, (ie to check the accuracy of input) since he had to water-lap and dunk the scope alot of times, in order to not risk being spotted. He extensively used it at Honshu (fourth chapter and patrol)

There is no evidence that Dick O'Kane ever used the Subsim Dick O'Kane method exactly as taught. As a master of the TDC he would have been intimately familiar with constant bearing attacks and would have used them.

Because of differences in how the game TDC works and the actual TDC it is not possible for us to replicate Dick O'Kane's practice. And when those of us who applied constant bearing techniques to the game TDC and came up with the attack method did it, we knew that Dick O'Kane had nothing to do with the technique.

In order to make our techniques memorable we chose to name them after prominent US Submarine Captains: hence the Dick O'Kane Technique and the John P Cromwell Technique.

These attack methods are historically feasible, meaning they could have been performed with the instruments and knowledge of the time. They cannot be shown to be precisely applied by anyone during the course of the war.

So you can do a game Dick O'Kane attack in a real submarine but you cannot use Captain O'Kane's method in Silent Hunter 4. Our game TDC will not allow it.

So what exactly is the issue? :06:

There was a page in O'Kane's book I was trying to mimic where he was overriding the position keeper and holding the bearing to target constant. I could find it if I have to (I know I've quoted the page number here before); but I'd have to check his book out again from the library. I don't think anyone is suggesting the guy didn't know how to use the TDC as it was intended.

Frankly, I was trying to intitiate a Fast-90 attack in a US fleetboat, but the PK/TDC doesn't allow for adjusting the AoB while panning the scope (aggravating). I noticed that O'Kane could do something with his TDC that I couldn't do in the game and that irritated me a little. ...did my best with what the PK/TDC allows in this game and this method sorta fell out of it. This game models a position keeper PK and TDC as if they are forever joined, whereas I think the full contraption in the fleetboat had both a PK and a TDC and they could somehow be operated seperately, but I don't know that for sure, I just suspect it was the case from what I read of O'Kane giving various commands.

I didn't really have any idea what to call the technique, except that Fast-90 seemed inappropriate because the TDC doesn't have the same whiz-wheel qualities of the U-boat TDC. RR came up with the idea to give the nod to O'Kane... seemed OK to me, and less heady than calling it the RR or AB technique. I mean I guess if I were to try to accurately classify it, I'd call it the "No TDC" method. You're basically disabling the TDC and pointing the nose of the sub where you want the torp to go. Not quite as fun as what you can do in the u-boat but it gets the job done.

Incidentally, I recall reading that the fleetboat PK/TDC seemed to be an adaptation of a battleship targeting computer. My take on the u-boat vs. fleetboat method of targetting is that it seems to be oriented to the types of attacks. The US fleetboat seems better equiped for single target tracking and stealthy ambush, complete obliteration of single target. While the u-boat seems better equipped for setting a generic course for lots of ships (convoys) and then popping up and unleashing hell on several targets quickly.

I like em both. :ping:

:hmmm: Ummm...

I would like to go on record once again to mention that when I first described and tried to mimic O'Kane's tactics. I did in fact use the TDC as I believe O'Kane did and it has always been somewhat a thorn in my side that it was dumbed down over time but kept the "O'Kane" monicker.

What people call the O'Kane method now is such a crude method it doesn't really do O'Kane justice. :nope:
http://www.subsim.com/radioroom/show...&postcount=134

...where I mentioned "develop a solution for a 20° bearing (70° AoB)" I was using the TDC to do it.


In his book, O'Kane did the same thing as I described in the above post... holding the aiming wire constant and firing as target points passed the wire. It was just one attack that he documented in his book, doesn't necessarily mean he always did it.