[derstosstrupp]

That’s a great video Jammo. Range ceases to matter at any impact angle, not just 90, so yes it will work at others as well and was the preferred method to use. Remember, all we care is the “lateral speed across the line of sight”, then we still have a right triangle. That’s by factoring in the sine of the AOB.

arcsin ( target speed / torpedo speed x sin (AOB))

And since it was ballistically advantageous to have an impact angle of slightly less than 90, often times they will wait until the 90° AOB to even shoot. Then that’s simple as well, simply take the arcsine of target speed over torpedo speed, and then lead the course by that lead angle, such that when you pull the trigger the target it will be AOB 90 when gyro is 0. That way they also then had the added benefit of being able to recognize easily an AOB of 90 right at the shot as confirmation.

So for example, target course is 0, I put myself on course 270. I want to compute the lead angle at 90° AOB, target speed 8.5 and torp speed 30. I do the division, take the arcsine, 16.5°. I then turn to course (270 + 17) 287, and wait for the target to cross the wire.