Manual targeting

teg916 · 08-26-09, 04:36 PM

I am confused.

Wouldn't the range to target change the gyro angle of the computer? If I shoot at a ship at a 90 degree AOB from 1000 meters away wouldn't the torpedo have to lead the ship more than if I am 500 meters away?

Or is there something I am missing?

JMV · 08-26-09, 07:32 PM

TORPEDO LEAD ANGLE

================================================== ==

Lead Angle = Arctan ( Target speed / Torpedo speed)

So if the target is making 12 knots, and you wish to fire a 30 knot T-III electric, then your lead angle is...

Lead Angle = Arctan ( 12 / 30 ) = 21.8 degrees

As long as you're within 5000 metres of the target track.

Another way to figure how much to lead 'em is via the Law of Sines, i.e.,

arcsin ( sin AOB ( Target speed / Torp speed ))

if AOB = 90; Target speed = 25; and Torp speed = 40, then Offset Angle of Collision (OAC) = 39 degrees

sharkbit · 08-26-09, 08:48 PM

Quote:

Originally Posted by teg916

I am confused.

Wouldn't the range to target change the gyro angle of the computer? If I shoot at a ship at a 90 degree AOB from 1000 meters away wouldn't the torpedo have to lead the ship more than if I am 500 meters away?

Or is there something I am missing?

Nope.
Try it. Set your scope at 000 gyro angle, go to the TDC, adjust the range. The gyro angle should stay the same.

There's a thread somewhere that shows this graphically. I'll see if I can find it, but not until tomorrow probably.

sharkbit · 08-27-09, 08:38 AM

Sorry-I couldn't find that diagram that shows this idea graphically.

It basically showed 2 ships on parallel courses at different ranges at time of firing and your sub/torpedo perpindicular to their courses.
The computed lead angle was the same for both ships, even though the ships are at a different range(assuming their speeds are the same).

All this can be figured with some trig or make a cool wizwheel-Hitman makes a cool one.
http://www.subsim.com/radioroom/show...t=kriegsmarine

teg916 · 08-27-09, 01:01 PM

Ok, that makes More sense. I didn't understand how to get the lead angle. Thanks

derrinurban · 08-27-09, 04:20 PM

I do the same sort of thing, but just made a chart for the different torpedo speeds. Since torpedo speed and target speed are constants, the shooting angle works for any distance.

http://img31.imageshack.us/img31/798...romthehip1.jpg

DU

JMV · 08-27-09, 05:03 PM

Sharkbit : I think I found it .

You're probably refering to thin post :

http://www.subsim.com/radioroom//sho...d.php?t=138312

It's SH4, but it does'nt really matter. See graphics at # 8 and 15.

sharkbit · 08-28-09, 08:15 AM

Quote:

Originally Posted by JMV

Sharkbit : I think I found it .

You're probably refering to thin post :

http://www.subsim.com/radioroom//sho...d.php?t=138312

It's SH4, but it does'nt really matter. See graphics at # 8 and 15.

THAT'S IT!!!!

Post #15 was the one sticking in my head.

Thanks JMV!

08-27-09, 08:38 AM	#4
sharkbit The Old Man Join Date: Apr 2008 Location: Denver, CO Posts: 1,529 Downloads: 334 Uploads: 0	Sorry-I couldn't find that diagram that shows this idea graphically. It basically showed 2 ships on parallel courses at different ranges at time of firing and your sub/torpedo perpindicular to their courses. The computed lead angle was the same for both ships, even though the ships are at a different range(assuming their speeds are the same). All this can be figured with some trig or make a cool wizwheel-Hitman makes a cool one. http://www.subsim.com/radioroom/show...t=kriegsmarine __________________ “Prejudice is blind. There will always be someone who says you aren’t welcome at the table. Stop apologizing for who you are and using all your energy trying to change their minds. Yes, you will lose friends, maybe even family. But you will gain your self-respect. You will know your worth. Once you have that, nothing can stop you.”

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08-26-09, 04:36 PM	#1
teg916 Watch Join Date: Aug 2009 Location: California Posts: 27 Downloads: 0 Uploads: 0	I am confused. Wouldn't the range to target change the gyro angle of the computer? If I shoot at a ship at a 90 degree AOB from 1000 meters away wouldn't the torpedo have to lead the ship more than if I am 500 meters away? Or is there something I am missing?

08-26-09, 07:32 PM	#2
JMV Sonar Guy Join Date: Jun 2008 Location: Galway-IRELAND Posts: 397 Downloads: 179 Uploads: 0	TORPEDO LEAD ANGLE ================================================== == Lead Angle = Arctan ( Target speed / Torpedo speed) So if the target is making 12 knots, and you wish to fire a 30 knot T-III electric, then your lead angle is... Lead Angle = Arctan ( 12 / 30 ) = 21.8 degrees As long as you're within 5000 metres of the target track. Another way to figure how much to lead 'em is via the Law of Sines, i.e., arcsin ( sin AOB ( Target speed / Torp speed )) if AOB = 90; Target speed = 25; and Torp speed = 40, then Offset Angle of Collision (OAC) = 39 degrees

08-27-09, 01:01 PM	#5
teg916 Watch Join Date: Aug 2009 Location: California Posts: 27 Downloads: 0 Uploads: 0	Ok, that makes More sense. I didn't understand how to get the lead angle. Thanks

08-27-09, 04:20 PM	#6
derrinurban Mate Join Date: Aug 2009 Location: Calgary, Alberta, Canada Posts: 54 Downloads: 33 Uploads: 0	I do the same sort of thing, but just made a chart for the different torpedo speeds. Since torpedo speed and target speed are constants, the shooting angle works for any distance. http://img31.imageshack.us/img31/798...romthehip1.jpg DU

08-27-09, 05:03 PM	#7
JMV Sonar Guy Join Date: Jun 2008 Location: Galway-IRELAND Posts: 397 Downloads: 179 Uploads: 0	Sharkbit : I think I found it . You're probably refering to thin post : http://www.subsim.com/radioroom//sho...d.php?t=138312 It's SH4, but it does'nt really matter. See graphics at # 8 and 15.