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View Full Version : How to use the stop watch to calculate speed


rascal101
03-31-07, 12:02 AM
Can any one provide some detail re using the stop watch to calculate target speed, I get all the other principles of manual targetting but dont see how staring at an animated stop watch produces target speed to input into the TDC. Most videos on the subject of manual targeting seem to gloss over this single part of the exercise



Can any one clarify calculating target speed

fullmetaledges
03-31-07, 12:33 AM
I think neal said it best by taking the targets maximum speed and divide by 2, if the target is in a convoy take the slowest ships maximum speed and divide by 2. So if the max speed is 14 then put in 7, that should get you close. With your position indicator and observations you can fine tune it. BTW the way the manual tells you to determine speed isn't working.

vois2
03-31-07, 01:03 AM
The chronometer speed tool does not work as of patch 1.1 or before, however,
regarding the finding of target speed, here is a post (http://www.subsim.com/radioroom/showthread.php?t=107766&page=12) which might be very helpful, post by vois2, 03-26-2007, 04:23 PM . You can use that chart for highly accurate speed estimates by following the directions on that chart.

Another useful conversion (as an aside for the reckoning of target position and speed) is that 5,000 yards is equal to 2.47 nautical miles (using Imperial system, of course). This can be rounded off at 5,000 yards = 2.5 nautical miles, since the SH4 map tool only provides accuracy to the nearest tenths place. (By using the 1 knot = 1 nautical mile per hours conversion, a target that travels 5,000 yards in 10 minutes of time, is moving at a rate of 15 knots.)

AOB reckoning comes after a lot of practice and experience. Ironically, it's not so important for a deadly attack run. That is to say, your knowledge of the precise AOB at any given time isn't even that helpful since it is so inaccurate. What is much more important is to work out as best as you can do so, the track of the target and thus his heading. Then simply position your ownship's heading to be 90 degrees from this. As a single numerical example, if you determine that his heading is 222, then you should get your sub traveling in a heading of 312 on your attack run. This results in highly successful attack runs when within 700 yards or so (0.4 nautical miles or less).