Sorry about the delay. Here is the video for the basic longitudinal spread.
Edit: now a much smaller 7zip file!
John P Cromwell attack technique
See the description in my last post. This one is strictly shooting Dick O'Kane style: longitudinal spread (all torpedoes take the same path to the target and are distributed from target's bow to stern by timing alone). Coincidentally, because it wasn't planned that way, this is also the first video ever released of a successful daylight surface attack. I'll replace the above AVI with a 7zip later. Enjoy! Please ignore the loss of sound synchronization in the last part of the video. I was cursed from the moment Hitman said, "this probably isn't a good idea."
OK, written instructions on how to execute this thing, written purely from memory, so don't shoot me:
With radar, plot two positions of the target 3 minutes apart onto the nav map. The distance between the two positions in hundreds of yards is the speed of the target, 600 yards equals 6 knots. Enter the speed into the TDC.
On the nav map with the ruler, draw a line from the first position, through the target and extending past your submarine. Measuring with the compass rose obtained with tool help on you can determine the target's course.
If this reveals that you can take a 45º approach angle to the track from ahead of the target, it's time to execute a John P Cromwell attack. Estimate the intercept point for a 45º approach. It doesn't matter if the estimate is wrong. With the protractor, click on the track further out from that point, then back toward the target at that estimated intercept point and lastly right beside your boat. Read the angle. It won't say 45º. Grab the vertex (the angle itself--the middle click point) and move it up or down the course until it says 45º.
Now turn your boat parallel with that line. If you have the 360º bearing plotter (hope you have the 3000 yd/meter variety!) this is a trivial task. If you don't, read the course off the protractor line with the ruler or protractor compass rose.
Pick your periscope aiming bearing. For a target coming from left to right, I'd pick 350º for fast Mark 14, Mark 23 or Mark 10, 345º for slow Mark 14 or Mark 18.
Now you have to calculate the angle on the bow (AoB). This is easy, don't leave now! The AoB equals 45º minus your lead angle. If your shoot bearing is 350º, you are 10º from the zero bearing. So 10º is your lead angle. 45º minus 10º equals an AoB of 35º. Now which side of the target are you looking at? In the video it is the starboard side, so the angle on the bow is 35º starboard.
For the other lead angle, our shoot bearing is 345º. That is 15º from the zero (360º) bearing. 45 minus 15 equals an AoB of 30º port or starboard, depending on whether the target is coming from the left or right. For whether the AoB is port or starboard, answer the question "what side of the target am I looking at?" There's your answer.
Range doesn't matter but bearing does. Point your aiming device, usually periscope, up the shoot bearing you've selected and press the send range/bearing to TDC button. You are ready to shoot.
Now it's a matter of remaining undetected and with the periscope pointed at the shoot bearing, send torpedoes as juicy parts of the target pass the crosshairs.
Watch the destruction!
Nisgeis will be by later with complete instructions on how to do the vector analysis, which will give you the periscope bearing for an attack giving you a perfect zero gyro shot every single time! Don't be afraid kiddies, a little math never hurt anybody. This is analytical geometery and very impressive to beautiful girls at the bar while you're in port! Demonstrate this on a napkin and they're YOURS!!!! Pay attention.