And vector analysis is so darn fast! It's perfect for when that Dick O'Kane suddenly goes bad because the target changed course.

just to show you...
 

Just to show the consequences of learning manual targeting, the O'Kane method, and the Cromwell attack technique, my boat embarked on a new career using Fred's pre-December 7, 1941 career start mod, so the crew could listen to all of the pre war and early war radio braodcasts. However, I neglected to change the game settngs, and did not realize the TDC was set to the game's default "automatic" settings until my boat was on patrol near Honshu. I figured we would have some fun before returning to Pearl where I could change the game settings. When I finally tracked down a solo freighter, we fired four torpedoes at 800 yards - a broadside shot - when it passed the 345 degree periscope bearing (the angle used in the O'Kane tutorial by RR). I did not wait until the torpedo firing light was green--it was yellow. I missed all four shots aft! Well, at least the radio is working. Now I just have to insert music in the radio mod!:p

OK, don't shoot me, it's been awhile since I had a drawing program actually working: since I had CorelDraw 4 on Windows 98SE. It was a fine program and I knew it well. Now I've stumbled on a free (<CorelDraw which is.... OH! If you want to buy it you also have to buy junk you don't want. Only $429!) program that seems to have all CorelDraw's tricks for free, Inkscape. Seems to me I also saw it available for Windows. Yup! http://sourceforge.net/project/showf...group_id=93438 hope that also gives the Windows version. Very useful.

So I used Inkscape to kudge out a line-drawing of the terms and methodology of the Cromwell Technique. I'll also do one that totally explains vector analysis and not make it at all about the John P Cromwell Technique, so people can see that it really is a universal solution that deserves to live apart from any straightjacket the Cromwell Technique might leave you the impression it is wearing.

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

Doncha just love exporting vector drawings as png files with transparent backgrounds? Stand by whilst I place a background. I'm assuming you know whether the AoB is starboard or port but I could add that if anyone thinks it would help. Linux is a wonderful (free!) thing!

Darn it
 

Darn it! Rain on my parade!! I just finished memorizing Old Tex's chart which dissected the AOB and lead angle to account for various target speeds when using the Cromwell attack techniqe. And what happens? Rockin Robbins presents a drawing showing wonderfully simple vector analysis that simplifies the techique by using on two lead angles. AAARRRGGGHHH!

Having failed at Automatic Targeting (see post 162), I returned to based and changed the setting to Manual Targeting and returned to sea, where I sunk a large modern passenger ship using manual targeting and the SCAF mod to get the correct aspect ratio and range (See Hitman's tutorial and my comments in a separate post re SCAF as a means to shortcut some of the steps). Now, I will turn my attention the John Cromwell attack technique if the occasion presents itself. Let's try the vector analysis at another AOB, rerun the calculations and see what happens .....

Thanks to Nisgeis, Hitman, aaronblood, gutted, Capn Scurvy, Old Tex, tale, Rocks n' Shoals, WernerSobe and others we have such a great bag of tricks to ruin our targets' day!:sunny:

And here you go, folks, a nice 3x5 card size (I can make the vector version available on Filefront if that will help) chart of the steps for vector analysis shots. Note that this will work for any angle of own course to target track with a perfect zero gyro shot every time without fail. This alone is worth the cost of admission!

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

Clear as mud? Any corrections, additions, deletions, bad jokes, etc?

don't pass them to your friends
 

If you want to prove to your friends that your are nuts, give them a copy of the 3 x 5 card and tell them it is the best Christmas present you have ever received. I printed 100 of them, and am having them made into stocking stuffers.:D

15 knots
 

Post 163 gives rules of them for target speeds of <15kts and >15kts. If the target is travelling at 15kts, is the lead angle 15 degrees?

RR, for clarification, if you were moving away from the target path (point of impact) would you set the AOB to 180 to use rear topedoes and aim the scope to 180 - lead angle?

heads
 

Rockin Robbins, now you even have Hydra getting his heads around it.

No you wouldn't. Your shoot bearing would be 180º to get the torpedo out of the aft tube. But everything else would be the same. You'd calculate the lead angle, move the periscope that number of degrees toward the target from the 180 bearing, in this case back to 170 if your target were at 15 knots or less. Hit the send range/bearing button to send the torpedo up that line and shoot as juicy parts of the ship cross the wire. You can break out the mai-tais before the torpedoes hit. You have a sinking on order by FedEx!

Thanks RR. So AOB remains zero and the shoot bearing (180 degrees plus or minus lead angle) to use aft tubes?:hmm::hmm::hmm::hmm::hmm::hmm::hmm::hmm::hmm :

Thanks RR
 

Thanks RR for the 3x5. I have it next to all the other navigational widgets on my desk. Great Work! :up: Old_tex

other angles
 

So we apply the Cromwell technique at a 45 degree angle to the target's course. Do the same principles apply (i.e. torpedo speed and target speed) when calculating the lead angle if you were attacking at 10 degrees? I assume at a 10 degree angle, the AOB for the target would be set at 10 degrees.

I pasted your 3 x 5 on the periscope, right above Old Tex's masterpiece. My son suggested that I tape it to my forehead.

don't lose sight
 

None of us should lose sight of the fact that information in this thread is remarkable and groundbreaking. It's right up there with Hitman's tutorial on manual targeting applying the target's aspect ratio, the related SCAF mod, Werner Sobe's tutorial on attacking via radar, Rockin Robin's tutorials on the Dick O'Kane method, and Lane's insane thread that shows scantily dressed photos/drawings of models pasted on the captain's office walls, doors, book covers and desk photos. There are some high I.Q.'s at work here and their imaginations are running wild. When will someone launch a submarine to the moon?:up:

Yes. Just draw your vectors with the correct angle. I see RR changed his card to say any angle, rather than 45 degrees. :) Any angle works, ahead or behind the target.

No, there are two cards: one for the John P Cromwell method, which always uses a 45º approach. And the second card is for the vector analysis method, which can use any angle, including the 45º angle of the John P Cromwell attack. They are two different cards.

The vector analysis card was separated from the Cromwell card because It needs to be liberated from the shackles of fixed angles and allowed to work as the versatile tool it is.

:up: Looks good. Slap a "Property of USN" on it so I can print it out and put it in my notebook.

Aren't you guys doing exactly what the TDC does: calculate lead angle for the torpedo, except by hand? Why not just use the TDC? Or am I mis-reading everything (probably)?

e.g. with the TDC:

Target course is 090T. You have your scope pointed at 330T. That means AOB when the target crosses your scope is 060 Starboard.

Enter bearing 330T, AOB 60 starboard, and target speed into the TDC.

PK off since you're aiming at a ghost ship. If you want a zero-gyro shot, turn your sub until the gyroangle indicator on the TDC reads 360 degrees.

Wait until target crosses the hairline, and shoot! No need to calculate lead angle by hand.