Optimal fire angle to target in scope at different ranges and speeds

[RoaldLarsen]

OLC and Pisces have made me think about this even more, and I now think there is an even better method to fire at an arbitrary angle from an arbitrary course, if you know target's course and speed:

0. Select tubes, torpedo depth, torpedo speed, and salvo spread, and open tube doors any time before step 9
1. Unlock periscope from target.
2. Rotate periscope to bearing 0 degrees (or 180 for stern tube shot).
3. Decouple periscope from TDC to allow manual input.
4. Enter target speed on TDC.
5. Set AOB on TDC as 180 minus the difference between your course and target's course. (or AOB = difference in course for stern tube shot)
6. Couple TDC to periscope.
7. Rotate scope to target
8. Lock scope on target
9. Get a range reading
10. Instantly unlock scope from target.
11. Instantly decouple periscope from TDC to allow manual input.
12. Instantly enter range on TDC
13. Instantly couple scope to TDC
14. Instantly rotate scope to desired aiming point.
15. Fire immediately

And to avoid having to take a range reading, if you can afford to wait for a 0 gyro angle shot:
0. Select tubes, torpedo depth, torpedo speed, and salvo spread, and open tube doors any time before step 9
1. Unlock periscope from target.
2. Rotate periscope to 0 degrees. (or 180 for stern tube shot).
3. Decouple periscope from TDC to allow manual input.
4. Enter target speed on TDC.
5. Set AOB on TDC as 180 minus the difference between your course and target's course. (or AOB = difference in course for stern tube shot)
6. Couple TDC to periscope.
7. Rotate scope to target
8. Lock scope on target
9. Fire when gyroangle reads 0.

To fire at an aiming point other than centre of target, adjust final steps as in my earlier post ITT.

[onelifecrisis]

Yup, that works, in fact it's the same as my method except you assume that the player knows the target course. The method I described was more generic: it will work with any type of AOB calculation, including the use of an AOB Finder (U-Jagd Tools mod and all derivatives) and/or an eyeball estimate, neither of which require the target course to be known.

[Paul Riley]

Originally Posted by RoaldLarsen

5. Set AOB on TDC as 180 minus the difference between your course and target's course. (or AOB = difference in course for stern tube shot

I was just wondering,is it neccessary to input the actual AOB at that moment?,as the TDC updates the AOB when you set it back to auto.What I have been doing is,if firing at SB side of a ship set angle of bow to 90deg SB respectively,and bearing to 90deg PS,set to auto and the correct AOB at that moment is updated,of course checking all other settings are correct.
Again,am I missing the crucial thing here?

Thanks.

[onelifecrisis]

Paul, that's actually the method I use when I know the target course and my own course is perpendicular to it (which is at least 90% of all my attacks).

They say the best mathematician is a lazy mathematician.

[Paul Riley]

So we are not so different after all...just seperated by a small act of fate,that lousy 10deg shot with the electric!
I know that won't be happening anymore!.

[RoaldLarsen]

Originally Posted by Paul Riley

I was just wondering,is it neccessary to input the actual AOB at that moment?,as the TDC updates the AOB when you set it back to auto.What I have been doing is,if firing at SB side of a ship set angle of bow to 90deg SB respectively,and bearing to 90deg PS,set to auto and the correct AOB at that moment is updated,of course checking all other settings are correct.
Again,am I missing the crucial thing here?

Thanks.

I'm not sure I entirely understand "and bearing to 90deg PS". If you are going to fire at the SB side of the target, and you are on a course perpendicular to target's course, then AOB is 90 when bearing is 0 or 180, and only then.

The TDC isn't magical. All it is doing when it updates AOB is simply adjusting the old AOB by the change in bearing, on a degree for degree basis. If you set AOB to 20, and then the bearing changes by 10 degrees, the TDC auto-updates the AOB to 30.

So if you want the TDC to maintain a correct AOB, you must input a correct AOB before you set the TDC to auto and move the scope. And if you set the TDC to accept manual input, then you must unlock the scope from the target while in manual input mode, so the scope doesn't rotate while the AOB is not being auto-updated.

[Paul Riley]

Originally Posted by RoaldLarsen

I'm not sure I entirely understand "and bearing to 90deg PS". If you are going to fire at the SB side of the target, and you are on a course perpendicular to target's course, then AOB is 90 when bearing is 0 or 180, and only then.

In that last description I was actually talking about an attack running parallel to a target,and firing when the UBoat is 90deg to the target,or at bearing 270 in the scope.
This type of attack I have found very successful before,when I am satisfied all critical data is correct,only in the future I will be watching the gyroscope readout,and not the bearing in the scope.

[RoaldLarsen]

Originally Posted by Paul Riley

Roald,

In that last description I was actually talking about an attack running parallel to a target,and firing when the UBoat is 90deg to the target,or at bearing 270 in the scope.
This type of attack I have found very successful before,when I am satisfied all critical data is correct,only in the future I will be watching the gyroscope readout,and not the bearing in the scope.

Oh.

You do understand that if you are running on a parallel course to the target that it will be impossible to get a 0 gyro angle shot, don't you?

The gyro angle is the number of degrees that the torpedo will turn from your course once it is launched. A 0 gyro angle shot goes straight ahead out the front, (or back) of your sub.

If you are running parallel to target, and target is at bearing 270, his AOB is 90, and your gyro angle to hit will be something close to 90. If his speed is 0, the gyro angle will be more than 90, if he is sufficiently fast, it will be less than 90.

[Paul Riley]

Sure,I know that
I have had some very good 90deg hull contacts at this position,and is one of my fav attacks.My problem started going perpendicular with a speed I was unfamiliar with.Do you follow me here Roald?,what happened,and the confusion it has caused (but no more now,thanks to you and OLC,and I think Pisces joined in on this).
I guess this concludes a VERY controversial topic then?

[Pisces]

Good you have a better feeling of what went wrong. I do think there was some confusion in this thread. (solving that by opening up another thread doesn't help, but OLC allready touched upon that subject ) Because all those angle are of a relative nature it is important to tell exactly how you approach the target (his course, your course) AND are facing him (bearing to target, what AOB does he show). Giving too much information is allways the best.

[Paul Riley]

Yes,I AM sorry for opening a new thread
Well,thanks to all concerned,in throwing light on this subject.
Lets hope it doesnt happen again,or i'm gonna throw them bloody electrics overboard,and load the torpedo men inside instead! Really,I think once I have become accustomed to the slow speed I will be using them as default,especially against convoys.I can't afford to make a single mistake against them now.