Old fashion method for determining SPEED

don1reed · 06-23-06, 09:00 AM

Here's an example of how it all works: Submerged, daylight torpedo attack.

I've spotted a small convoy on my port bow, heading east. I adjust my course and/or speed to get into a collision course with the medium merchant (c2), so that it's bearing is constant:

My Course = 006° True...

The target ship's AOB appears to be about 30° starboard...
I then apply the information to my combination "whiz-wheel"...

My "whiz-wheel" consists of 3 layered wheels.
The Large wheel represents TRUE Compass.
The Middle wheel represents the Submarine.
The Small wheel represents the Target.

Now that I know the target's Bearing and AOB, they point to the target's TRUE Course of 095°.

I need to compute the target's speed to complete my firing solution, so I flip the whiz-wheel to the opposite side and use the circular slide rule.

After plugging the info into the vorhaltrectner/TDC, I slow the boat to 1 kn. and wait for the target to reach about 70° AOB before pulling the trigger.

I might add here, that I never worry about RANGE.
Something I learned in the ACADEMY is, if the target (see above) fills 1/3 of the viewfinder in x1.5...you are within 1000m. So, whenever you get a sight picture like that (NO MATTER THE WEATHER)...you are close enough to kill.

Hope this made sense.

cheers,

06-23-06, 09:00 AM	#6
don1reed Ace of the Deep Join Date: Dec 2004 Location: Valhalla: Silent Generation Posts: 1,149 Downloads: 910 Uploads: 0	Here's an example of how it all works: Submerged, daylight torpedo attack. I've spotted a small convoy on my port bow, heading east. I adjust my course and/or speed to get into a collision course with the medium merchant (c2), so that it's bearing is constant: My Course = 006° True... The target ship's AOB appears to be about 30° starboard... I then apply the information to my combination "whiz-wheel"... My "whiz-wheel" consists of 3 layered wheels. The Large wheel represents TRUE Compass. The Middle wheel represents the Submarine. The Small wheel represents the Target. Now that I know the target's Bearing and AOB, they point to the target's TRUE Course of 095°. I need to compute the target's speed to complete my firing solution, so I flip the whiz-wheel to the opposite side and use the circular slide rule. After plugging the info into the vorhaltrectner/TDC, I slow the boat to 1 kn. and wait for the target to reach about 70° AOB before pulling the trigger. I might add here, that I never worry about RANGE. Something I learned in the ACADEMY is, if the target (see above) fills 1/3 of the viewfinder in x1.5...you are within 1000m. So, whenever you get a sight picture like that (NO MATTER THE WEATHER)...you are close enough to kill. Hope this made sense. cheers, __________________ [SIGPIC][/SIGPIC] During times of universal deceit, telling the truth becomes a revolutionary act. ~ George Orwell Last edited by don1reed; 06-23-06 at 09:14 AM.