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View Full Version : Easy Way for Calculating Speed


capt_frank
11-30-07, 10:12 AM
If you are using the Map Update mode, you can calculate speed using the map ruler tool to determine the number of yards traveled between two travel points. However, when you are marking these travel points, note the game time so that you will be able to ascertain the game time it took to travel between the two points.

Now you will have the following (example) information:

Travel from point "A" to "B" took 5 minutes over 2400 yards.

Now divide the 2400 yards by 33.75619715, then again by 5 and you will have your subject's speed in knots. The 33 number is derived from the formula of: 1 knot = 33.75619715 yards/minute.

You can check your calculations here: http://javascript.internet.com/math-related/distance-speed-time.html

Just another way to calculate speed, I hope you find this to be helpful or at least interesting.

You can also use the ruler tool to determine your distance to the subject and that gives you a range.

And using the course/heading that you have already established can help you determine your AOB.

And never having to leave the Map view, which would be realistic given the use of the map in WWII for calculations.

Anyway, just interesting stuff.

ReallyDedPoet
11-30-07, 10:35 AM
Nice info :up:

Another way ( for Imperial ) is to get the target in your optics, time how long it takes to go bow to stern. Take this number and divide it into the ships length. To convert this to knots, multiply that number by .6 :yep:

Got this info from Hitman awhile back.


RDP

black1
11-30-07, 12:57 PM
I thought it was multiplied by 2, I could be wrong but i was using 2 and all seemed well enough. Can you confirm this for me mate, thanks.


I thought it was 2, here you go: THIS IS HOW I DO IT NOW: Use a handheld stopwatch, and the length table below (or your paper version of the recognition manual, if you have it).I set the crosshair of my TBT or Periscope ahead of the boat and start the stopwatch exactly when the bow passes through my sights. You must NOT use target lock ("L" key), and your sub must be stationary or near stationary. I stop the watch exactly when the stern passes through. Next, I take the length of the ship (listed in the recog.manual) and divide by the number of seconds it took to pass through my sights. This gives me the target speed in meters/second, which can easily be multiplied by 2 to find speed in knots (actually 1.94, but 2 is close enough). Example: The Yamato (263 meters long) passes through my sights in 30 seconds. 263meters/30seconds = 8.8 m/s. Multiplied with 2 we get 17.6 knots... Good enough for Navy use. This technique works at almost any AOB and any distance as the time to run one boatlength is the only thing measured and is the same no matter where you see it from. But remember to stop your sub for this.