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Old 06-20-2020, 09:41 PM   #8
Join Date: Jun 2020
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Default Think I got the calculation...

Ok, so in the video where the 37 degree bearing and 3500 meter distance is calculated I think I know what to do, assuming we don't want to use a 35m mast default.


1. Immediately initiate the 90 degree turn to port after the 3500 meter distance is marked
2. We know from the current disc reading, that our distance to intercept was a little over 2100 (2106 to be precise)

3. We know (from a slide rule that I'm still looking for) that a 185 meter course turning 90 degrees at 3 knots gives us a 185 meter quadrant which, gives us a radius of 117 for that quadrant. (Would be nice to be able to calculate this using just knots and the rudder)

4. Subtract 117 from 2104 and let's just say it's 1990. (Note: we are only using the 117 Transfer. We don't need to worry about 117 advance, or the target ship's advance towards us in this time because we will do a bearing check instead and that will take care of it for us.)

5. While in the turn, set the needle at 1990.

6. Right when the turn is finished and we are on our new course, mark the bearing of the vessel used to calculate the original 3500 range. It should be about 50 degrees. The flip side of that is 40 degrees. Line up 1900 with 40 degrees. Then use the other needle to mark 50 degrees.

7. The 50 degree mark is how far that ship is from the intersection point. About 2340ish. From this we can recalculate how far that ship is from us but, we shouldn't need to now. We can just adjust speed to get 500-1000 meters from the intersect point and if we need to, calculate how fast the target will get there

Last edited by Krellian; 06-20-2020 at 09:55 PM.
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