Fast 90 Attack tutorial for Wolfpack

derstosstrupp · 04-26-20, 07:10 AM

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.

II WO · 05-26-20, 11:56 PM

nice vid Jammo! Now can you do one with map tools and as little actual math as possible? (non 90°)

(like this: https://www.subsim.com/radioroom/sho...d.php?t=233175)

ElJammos · 05-27-20, 08:45 AM

Thanks.

I'm not quite sure what you mean by that though... You mean, just shooting torps using map tools without calculating anything? Could be doable indeed... I was actually working on a tutorial on how to shoot based on matching speed and course (an idea I completely stole of Stosstrup, but he knows.).

At any rate, if there's something you'd like me to do a video on, let me know.

II WO · 05-27-20, 05:07 PM

yeah stuff like getting lead angle off the map and subsequently doing that for more obscure aob than 90. i think i figured it out now but another perspective is always interesting. (slime)

derstosstrupp · 05-27-20, 07:47 PM

Definitely, it can easily be done on the map:

1. Draw a line toward the “target”.
2. From that line draw a line at the angle of the AOB you intend to shoot at (50 in this case). Make the length of that line equal to the target speed, in this case 15 kn.
3. Draw a line of a length equal to the torpedo speed from the starting point, 30 knots in this case.
4. Move the target speed line down and adjust the torpedo line til their ends meet. Do not change the lengths of the target and torpedo lines though!
5. The lead angle will be the angle at the starting point (22.5 here).

04-26-20, 07:10 AM	#1
derstosstrupp Grey Wolf Join Date: Aug 2008 Posts: 918 Downloads: 490 Uploads: 0	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. __________________ Ask me anything about the Type VII or IX! One-Stop Targeting Shop: https://drive.google.com/drive/folde...WwBt-1vjW28JbO My YT Channel: https://www.youtube.com/channel/UCIJ...9FXbD3S2kgwdPQ Last edited by derstosstrupp; 04-26-20 at 07:31 AM.

05-26-20, 11:56 PM	#2
II WO Swabbie Join Date: Apr 2010 Posts: 6 Downloads: 32 Uploads: 0	nice vid Jammo! Now can you do one with map tools and as little actual math as possible? (non 90°) (like this: https://www.subsim.com/radioroom/sho...d.php?t=233175) Last edited by II WO; 05-27-20 at 12:05 AM.

05-27-20, 07:47 PM	#5
derstosstrupp Grey Wolf Join Date: Aug 2008 Posts: 918 Downloads: 490 Uploads: 0	Definitely, it can easily be done on the map: 1. Draw a line toward the “target”. 2. From that line draw a line at the angle of the AOB you intend to shoot at (50 in this case). Make the length of that line equal to the target speed, in this case 15 kn. 3. Draw a line of a length equal to the torpedo speed from the starting point, 30 knots in this case. 4. Move the target speed line down and adjust the torpedo line til their ends meet. Do not change the lengths of the target and torpedo lines though! 5. The lead angle will be the angle at the starting point (22.5 here). __________________ Ask me anything about the Type VII or IX! One-Stop Targeting Shop: https://drive.google.com/drive/folde...WwBt-1vjW28JbO My YT Channel: https://www.youtube.com/channel/UCIJ...9FXbD3S2kgwdPQ

05-27-20, 08:45 AM	#3
ElJammos Swabbie Join Date: Dec 2017 Posts: 9 Downloads: 1 Uploads: 0	Thanks. I'm not quite sure what you mean by that though... You mean, just shooting torps using map tools without calculating anything? Could be doable indeed... I was actually working on a tutorial on how to shoot based on matching speed and course (an idea I completely stole of Stosstrup, but he knows.). At any rate, if there's something you'd like me to do a video on, let me know.

05-27-20, 05:07 PM	#4
II WO Swabbie Join Date: Apr 2010 Posts: 6 Downloads: 32 Uploads: 0	yeah stuff like getting lead angle off the map and subsequently doing that for more obscure aob than 90. i think i figured it out now but another perspective is always interesting. (slime)