Speedometer Precision

[magic452]

Originally Posted by Ruff EL

elaborate again your AoB procedure please?......are you determining their course from the compass rose tool?

Use the three minute rule three times, 9 minutes. This will give you a very accurate speed, down to a quarter knot. It will also give you a very accurate target course. Remember that radar updates are every 20 seconds. Start your measurements at an update.

Use the compass rose to get that course in degrees, remember this reading.

First set speed and send to TDC.

To set AoB turn the AoB data input dial about what you guess is the Aob and send to TDC. The target ship dial on the top left side will turn.

Adjust the data input dial till the target ship dial shows the very same target course that you read off the compass rose. With the PK on that course will remain constant, if it does you have perfect AoB.


You also have very good speed +/- 0.5 knots.

You can do all this off radar readings so you have 2/3 of your firing solution and haven't seen the target yet.
If you don't have radar yet sonar will give you the same result but will take a bit more work.

With the 3D TDC you can set range to your best guess and point the scope at the target, estimate from the nav. map, and the PK will track the target for you. Radar updates will show what you need to do to get a good firing solution.

If the target stays on course and the AoB doesn't change all you need is a couple of steadimeter readings for range when the target gets closer and your all set to go.

Magic