John P. Cromwell attack technique on order

[Rockin Robbins]

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!

[Rockin Robbins]

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!



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

[I'm goin' down]

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.

[I'm goin' down]

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?

[Hydra]

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?

[I'm goin' down]

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

[Rockin Robbins]

Originally Posted by Hydra

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?

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!

[Hydra]

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 :

[old_tex]

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

[I'm goin' down]

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.

[I'm goin' down]

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?

[starbird]

Originally Posted by I'm goin' down

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.

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.

[Rockin Robbins]

Originally Posted by starbird

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.

[Munchausen]

Originally Posted by Rockin Robbins

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.

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

[cleverusername]

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.