View Full Version : Bearing Rate Computer
Puster Bill
08-06-08, 08:00 PM
I know it's post WWII, but I suppose you could cheat ;)
http://img207.imageshack.us/img207/3040/brcouterhs2.jpg
http://img225.imageshack.us/img225/1273/brcinnerwh5.jpg
Cut out the two wheels, and pin them together along with something for a cursor. Google "Bearing Rate Computer" to find instructions on how to use it.
Rockin Robbins
08-06-08, 08:11 PM
Pretty awesome! Do you know what year that circular slide rule of yours came from? Do we know for sure that nothing like that was used during the war? I know they did bearing rate plots and derived enemy relative course and speed. They must have had a similar tool but I bet it was a straight slide rule (a slip-stick), not a circular one.
This is important because bearing rate charts were extensively used by the real submarines and we don't use them at all.
Puster Bill
08-06-08, 09:28 PM
For targeting problems, they used the Submarine Attack Course Finder/IS-WAS. It was also a circular slide rule, and this thread has all you need to make and use one:
http://www.subsim.com/radioroom/showthread.php?t=106923
Are you sure they are only 2 disks, and not supposed to be 4 free rotating scales?
Puster Bill
08-07-08, 09:01 AM
You know what, I think you may be right. Here is an actual photograph of one:
http://img376.imageshack.us/img376/4234/bearing20rate20computerbo8.jpg
So really the only difference is that you print each page twice, and cut them out appropriately.
Good catch. I never really used it much, I just made one and fiddled with it a bit.
Yeah, I noticed the 90 degree mark (sine scale) was against about 4050 yards (pretty much 2nm) so I started wondering if that relation was important. But then I thought "closest point of approach" calculations or matching AOB vs range would allways come out the same. That can't be good. It's probably in that state because of the last user's calculation, before photocopying.
Puster Bill
08-09-08, 07:28 PM
Yeah, I noticed the 90 degree mark (sine scale) was against about 4050 yards (pretty much 2nm) so I started wondering if that relation was important. But then I thought "closest point of approach" calculations or matching AOB vs range would allways come out the same. That can't be good. It's probably in that state because of the last user's calculation, before photocopying.
I grabbed it from a PDF of a manual on how to do TMA's and use the Manuevering Board. It wasn't clear how many wheels there were.
Seminole
08-09-08, 07:38 PM
but I suppose you could cheat
Ohhhh...ohhhh...ohhhh..what he said...I feel so dirty...must go take a shower....man if I get killed in game ..I'm such a fanatical ded is ded player...I have to wait 25 years in real time before playing again in order to simulate growing up and being re-educated in sub warfare....
(Yeah..right :shifty: )
Thanks for the calculator...
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