It's sort of doing what the TDC does backwards. The TDC will tell the torpedoes where to go if we shoot now as it predicts where the impact point will be. The vector analysis is only for a situation where we want the impact point to be in a specific place and want the torpedoes to go straight out.

The advantage to it is that it is largely range insensitive, except with extreme ranges, whereas the larger the gyro angles are, the more important the range is (due to the torpedo's reach, where it travels a certain distance, before it changes course to its gyro angle order). With a large gyro, the torpedo sort of bends back on itself and will only intercept a target on that course at that speed at that range, give or take a few hundred yards.

While I'm at it and running my Linux installation I took about five minutes and schlepped out this 3x5 card for the Dick O'Kane technique. Now that you have all of them in the same place, you can see how alike they are, eh?

http://i196.photobucket.com/albums/a...etargeting.png

They are all near zero gyro attacks and relatively insensitive to range. The vector analysis attack is completely insensitive to range as long as the torpedo can get to the impact point.

They are all longitudinal spread patterns, that is the torpedoes all advance toward the target in a single line. They use the motion of the target and their timing to hit different parts of the target.

All these attacks can be set up in their entirety a half hour before you want to shoot. Then you maneuver your boat into position and shoot at your leisure. There is no hurried mashing of information into the TDC before everything goes stale. When it's time to shoot you have nothing to do but mash the button at appropriate times and sip your mai tai.

Look how far we've come in a year! And look at all the people who have contributed. None of this is purely mine. I'm just the big mouth that gets the word out.:arrgh!:

That, to me, is the real beauty of this. If you play like "real life" and don't time compress yourself to the gratification of firing off the fish and then wait couple of minutes for the payoff, you can really come to appreciate the approach phase of the attack. You compile good target data and set yourself up so you don't have to drive like a drunken sailor at flank speed to get off your fish. So long as the target doesn't change course on you, and your numbers are good, you can make your attack whenever and wherever you want along the track, using the prefigured analysis.

It just makes the attack seem so much more 'professional'. You can spend your time on your final approach making sure the doors are open and the fish are set just how you want them and checking off all the little things that sometimes get forgotten when things aren't prepared. You can even use that extra time trying to be real fancy by setting up an attack on a second target, or paying more attention to what the escorts are doing. You're also just more prepared if something about the target does change, because if you really understand your situation, it should be fairly easy to figure out what, if anything, you can do to put yourself back on track to fire. Most target changes aren't going to completely invalidate your previous solution, and if you keep your vector drawing handy a new solution can often be as simple as changing one line and remeasuring one angle.

Hey there, thanks for this amazing new method. I've tested it and it works "just" perfectly. Great job!

I just want to ask one thing... I was curious to try the BAAANG you talked about in the first posts of this thread. You said that sending a fish to the stern, mid and bow they are going to hit almost at the same time.
I just can't figure out how to do it because in my game merchants don't go backward easily in my game! :rotfl:
I don't think I have to turn or to mess up with the TDC so how do you do that?!

It's not really easy because you DO have to mess with the TDC and give up some accuracy on shots 2 and 3. Here's the deal.

Set up as usual for your first shot. Have the periscope on the shoot bearing and shoot torpedo #1 at the stern. Then quickly jump just in front of the target, freeze and press the send range/bearing button. Send this puppy to the MOT. Jump just ahead of the boat again and press the send range/bearing button. Shoot this one at the bow.

It's vitally important that you don't move the periscope after you press the send range/bearing button, because that's where the next torpedo is going. Your angle on the bow is going to be slightly inaccurate for shot 2 and 3 (we don't have time to adjust it), but shouldn't mess up the shot. At most it will make a couple of yard difference in where the torpedo strikes the target.

Since the first torpedo you fire has to go the longest distance, they will strike at about the same time. And instead of the normal longitudinal spread where the three torpedoes advance toward the target in a single line, easily outmaneuvered if the target sees it soon enough, your divergent spread is three torpedoes taking three different tracks, side-by-side toward the target. This spread is much more difficult to avoid.

Shooting in the order stern/MOT/bow gives you the most divergent possible spread, bow/MOT/stern gives you the least divergent spread. Because of the nature of the spread you have to use the TDC. Only the first shot could be set up using vector analysis.

I keep reading "enter xx into TDC" in this thread.
I have been entering nil into the TDC as the whole point of the method is the determination of a point for the torps to hit. Given I had to manually clear relics of former attacks, but that's it. Am I doing something wrong (because I'm still hitting targets)?

Mmm... sounds like a decent plan to blow up things :up:
I'm on my way to try it.

Thanks RR!

Some people like to check their solution with the TDC, but there is no need to use it if you are using a longitudinal spread by waiting for the parts you want to cross the wire. If you want to fire a diverse spread, by using the spread wheel, then you have a problem of the target moving and the aiming point (stern) is moving as well. You can use the spread wheel without using the TDC, but you'll have to be quick, as the target is moving and your torpedoes will lag behind a bit, as it will have moved on. Depending on the speed of the target, the results will vary.

You can compensate for this by pre-determining at what interval you will fire the torpedoes at and then working out how far the target will have moved and using that plus the target's length to work out your spread. To make this easy, use the TSAC (Torpedo Spread Angle Calculator). A target travelling at 1 knot will travel 100 feet in one minute, so if the target is going at 12 knots it will travel 1,200 feet per minute.

But that's all getting quite complicated. If you are firing torpedoes with the historical contraint, then you'd need to leave a gap between torpedoes, but as this is a game you don't if you don't want to. Use the TSAC to work out the target length in degrees, with the correct torpedo run length (from your drawing, it's the torpedo course up to the point where it intersects the target's track). Wait for the stern to cross the wire and then dial in the gyros until you have covered the whole ship.

Give it a try and see what happens. You may find that your torpedoes don't give full coverage, but try it and see what happens.

Angron, there are two ways to execute this attack. The first method is by entering target speed and AoB into the TDC and estimating a lead angle. The TDC computes the actual lead angle and sends the torpedo up that vector, which may be slightly different from the zero bearing angle. The difference will not impact the accuracy of your shot.

The second way is by vector analysis, which depends on having a zero value in the TDC target speed, and/or an AoB of zero or 180. (I always do both because I'm paranoid) It does not use the TDC, and since we cannot turn it off, having those values inserted is our workaround.

RR you have just given me a crazy idea which might even speed up the lead angle calculation.

As the TDC lead angle deviates from the calculated one due to minor inaccuracies in setting targets AoB and speed etc. .... If you'd feed the TDC with the targets speed at a 0° bearing at an 45° angle (or whatever angle you approach), wouldn't it then calculate a lead, which you could read of the 360°bearing plotter and use for the lead of a zero gyro angle shot?

e.g. Say you have fed the TDC values as stated before and it would send your torpedo down the 8° bearing line, you would then aim your actual lead at 352° and have the torpedo go down the 0° bearing line.
Could this work? It looks good on my screen, but I don't have the bearing plotter running.

That's really a great idea and I do it all the time just to make sure I have a small gyro angle. If you do it the way you describe, your next send range/bearing to TDC operation would be in a couple seconds, after you pointed the periscope at the lead angle and sent the range/bearing a second time. That will give you a perfect zero gyro shot.

The way I do it is to set up my rule of thumb lead angle for the actual attack and then go to the attack screen to see what kind of gyro angle you have, typically a couple of degrees. If you instead find a 10% gyro angle, you can be fairly sure you've done something wrong. The most common mistake would be setting low speed for the torpedo when you picked a lead angle for fast torpedos.

why?
 

I just blew another attack using the Cromwell technique. This time my boat was off course. Here is my question. Once you have set the torpedo to run at a zero bearing in prepartion for a Cromwell attack why do you subsequently need to click the range button on the stadimeter when you move the crosshairs of the periscope to the bearing of the firing angle? It is counterintuitive.

Example. I set the stadimeter so the torpedo will intersect the target at 0 degrees. Assume the target is approaching from port at 10.9 kts. According to Old Tex's chart (screw the vertoring analysis), for a torpedo speed of 46 kts the AOB should be set at 37 degrees and the periscope aiming angle set at -8 degrees (352 degrees). We are set, except we still have to enter the range. We do this by grabbing the range handle on the stadimeter, pulling it to the right. Next, according to your instructions, we aim the periscope at 352 degree firing angle and click the range button on the stadimeter.

Why do that last step? If the torpdeo track was already set to run at 0 degrees, won't it intersect the target at 0 degrees. Clicking the range button when the periscope is aimed at 352 degrees moves the torpedo track (to port I believe). I don't understand the logic behind the last step. Enlighten me, please.

It sounds like you are doing the same thing twice and differently. :hmmm:

Manually setting the torp up to swim up the 0° bearing line is vector analysis. For JPC, you feed the TDC the speed and AoB data so it sends the torp up the 0° bearing line, while your scope points at the lead angle.
Aside of the simultaneous bearing sending, sending a "fake maxed" range is possibly to amend minor data input errors, which may result in lifeboats being able to slip your torps.:ping:

I still do not comprehend. Do I perform the last step, or not? Rockin Robbins says the first step (setting the TDC variables to zero degrees for Speed, Range and AoB) clears the the data in the TDC. Then he instructs to input speed and AoB. Finallly, he instructs that you aim the crosshairs at the firing angle and set the range. I do not see that I have duplicated the same task, i.e. range?

Method: Vector Analysis at 45° with chart
If you clear the TDC and approach at 45°, there is no reason why you input anything into the TDC afterwards, as Old-Tex's chart gives you the lead angle for this situation. So, once the TDC is clear you'd be set up and just need to point your periscope. No further data sending required.

Method: JPC
If you input speed and AoB into the TDC, you have to send the bearing at the lead angle, so the TDC sends the torp up at 0°. Doing so, there is no reason to initially clear the TDC as you override it with values anyways.
If you look at RR's 3x5 card for JPC, you'll see that clearing the TDC is not mentioned on it.

The range transmitting is actually unimportant as the range is already resolved into the lead angle, but since there is no other way to send a bearing (either for clearing the TDC or setting up the lead angle) a range value comes into play that doesn't do diddly.