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Cloud_Cat
04-27-2005, 07:49 PM
Probably a ******* question, but when your in the "world" map and you become aware of a Ship/convoy and its course etc is it possible to plot an interception course with out having to do a relativly blind search pattern in front of where you think your target may be?

I.E. is it possible to work out where the target is going to be in say an hour if it mantained its cousre and speed and then relate that to the map?

Also is it possible to work out a targets course from AOB, your heading and bearing? it would make things easier for shadowing a ship until more favourable conditions appear for an attack.

I guess there are really simple answers to these problems but at this time in the morning me and my brain aren't on talking terms.

Thanks anyway.

Regards

One last thing what the hell am i doing wrong with my Sig picture? Works on other sites but not this one....? Am i missing some impotant piece of text at the beginning of the host address?

Thanks again. (definatly going this time)

Cloud_Cat
04-27-2005, 07:49 PM
Probably a ******* question, but when your in the "world" map and you become aware of a Ship/convoy and its course etc is it possible to plot an interception course with out having to do a relativly blind search pattern in front of where you think your target may be?

I.E. is it possible to work out where the target is going to be in say an hour if it mantained its cousre and speed and then relate that to the map?

Also is it possible to work out a targets course from AOB, your heading and bearing? it would make things easier for shadowing a ship until more favourable conditions appear for an attack.

I guess there are really simple answers to these problems but at this time in the morning me and my brain aren't on talking terms.

Thanks anyway.

Regards

One last thing what the hell am i doing wrong with my Sig picture? Works on other sites but not this one....? Am i missing some impotant piece of text at the beginning of the host address?

Thanks again. (definatly going this time)

quillan
04-27-2005, 08:04 PM
I'll answer your questions in reverse order. Your sig is lacking the image tags, so it's showing as a link rather than as a picture. This forum doesn't allow HTML, so you have to use the VBcode instead. Do it like this instead: <pre class="ip-ubbcode-code-pre">http://onfinite.com/libraries/429115/c4e.jpg </pre>

Yes, you can figure a course from your observations, but you'll need some modified map tools to do it. Draw a line from the center of your ship to the center of your target on the map, using the ruler tool. Then take the protractor, place the first point in the center of your sub, the second point in the center of the target ship, and draw the third leg at the AOB from the direct path. That's the line representing the course of the target. Now, you'll need something to tell what that heading is, which is where the mod tools come in. Check the SH3 Essentials sticky at the top of the forum. There's a link in there to Jiim's Nav Tools, which are great. It will change the cursor for the protractor tool to be a real 360 degree protractor, which you can use to read the course of the line you just drew.

As to interception, the way I do it is to draw a line representing the course of the target convoy. Then I take my calculator, which I have sitting on the desk next to the computer, and figure out how far the target can go in a certain number of hours at its current speed. I have to work this out in kilometers. Just multiply speed in knots by 1.852 to get speed in Km/h. Then I draw a circle of that radius using the compass tool. The point where the line intersects the circle is where they should be at the chosen time.

lowdown762n2003
04-27-2005, 08:30 PM
Yes.

Generally I do this

1a. If the target says slow I put his speed at about 7 knots
1b. If it says medium generally it can run up to 10 area.
2. I then measure, with the ruler, to see how far I am away from the contact.
3. Use this to tell at what speed you need to run for how many hrs to intercept the target where it is at. Like if your 20 away and your boat at flank does 20 then you know you could reach it in 1 hr.
4 Use the target speed and ruler to measure how far he would go in te same time. If it takes you one hr to reach him and he is slow (7 knots) Measure along his course until you reach 7 k father from where he is know. This is where he will roughly be in 1 hr.
5. Use your ruler and draw a line to where he will be. Then head in that direction. at the best speed to reach the intercept point. Like if you measure from you to the intercept point and got 17 this time, drop your speed till you around 17 to meet almost perfectly.

http://i4.photobucket.com/albums/y118/LowDown762n/Intercept.jpg

This is a very rough drawing the blue line is you. It gets more complicated than this sometimes. This is just in general. However other people may have a better way to say this or to plot an intercept. On step 3 you would run at 17 and intercept in one hr. Sometimes you want to be ahead of the point you calculated to intercept to make up for your and his speed variances. Someone will surely call me on the carpet for my kilometer knot difference but the previous reply gives you the conversion factor. Thanks quillan

lowdown762n2003
04-27-2005, 09:45 PM
Took some screenies of an intercept to show you how I do it.

http://i4.photobucket.com/albums/y118/LowDown762n/Intercept0.jpg

This is the original contact report I'm getting to the point where convoys are evident but same principle.

http://i4.photobucket.com/albums/y118/LowDown762n/Intercept1.jpg

Here I am measuring the distance from me to the contact. Which reads 149.6. My current boat will do 17 at flank. So 149.6 divided by 17 = 8.8. So if I headed at flank to this point it would take me about 9 hrs. So I use 9 hrs as it is easier.

http://i4.photobucket.com/albums/y118/LowDown762n/Intercept2.jpg

It's a slow convoy so there speed should be around 7 knots. So in the 9 hrs it will take me to reach them they will travel 7 knots x 9 hours = 63. So I measure along there heading 63. and click so that the line stays.

http://i4.photobucket.com/albums/y118/LowDown762n/Intercept3.jpg

There was a screenie that didn't take before this one. It was where I measured from the 63 mark of the convoy path to the bow of my boat. It measured 120 roughly. So again I did a 120 distance divided by 9 hrs = 13.33333. This is the speed that you need to take to reach this interception point in 9 hrs. The closest speed I have is 14 knots. This would bring me in ahead of the convoy. Which is a good idea.

Now to the above picture. This is showing where I got the angle from my bow to the interception point. Remember North is 0 and 360 degrees. This contact is 20 degrees to port of north or to the left of north. If the point your measuring degree on is to the left of north you minus the reading from 360. If it is to the right of north then you add your reading plus 0....duh just use the reading there the same. lol. If I were heading due north, or from my point straight up then the intercept point is to the left of this. Therefore I take 360 and minus 20 degrees = 340. So I set my heading to 340.

http://i4.photobucket.com/albums/y118/LowDown762n/Intercept4.jpg

Hey were intercepting.....lol

http://i4.photobucket.com/albums/y118/LowDown762n/ConvoyAhoo.jpg

Hummmmm which one to kill..........

lowdown762n2003
04-27-2005, 10:02 PM
The method I have described, as best as I could, has worked for me everytime I have used it. As I'm sure someone will point out, the distances should be in kilometers, and 1 kilometer does not equal 1 knot for 1 hr. I don't know if the measurements are in a format of knots times time, ie 2 knots x 2hrs = 4 on the measurement, or what is going on on that. However as I've stated this gets me in on single ship or convoy every time. Someone will chew me about the mechanics of my plotting but results are what I'm after and this has never failed me.

Jex_TG
04-28-2005, 05:55 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Then I take my calculator, which I have sitting on the desk next to the computer, and figure out how far the target can go in a certain number of hours at its current speed. I have to work this out in kilometers. Just multiply speed in knots by 1.852 to get speed in Km/h. </div></BLOCKQUOTE>

Why aren't distances shown as nautical miles? Surely that would make things more simple wouldn't it? Perhaps a mod?

tcrossma
04-28-2005, 09:18 AM
Thanks lowdown, that explanation makes sense to me. I'm still just on my first mission and was having trouble with the whole intercept process.

Question: Since you know the point where you expect the convoy to be at said time, why not just set a waypoint for that spot instead of having to figure the heading?

Thanks,
tim

lowdown762n2003
04-28-2005, 11:32 AM
You could set a way point just as well. The reason I do not do it that was is becuase I use the way points to get me to my patrol route. So I leave the waypoints set to get me there and just manually intercept in targets I come upon. This allows me, after the intercept, to just say "Return to course." and I'm headed again to my patrol zone without having to replot it every time.

AStotzer
04-28-2005, 12:39 PM
Thanks guys. I've been learning a lot from Wazoo's charting and navigation tutorial, but this was also very helpful. He hasn't covered the charting of 'reported' contacts yet, and I've been wondering how to do this, especially since I just eyeball it and completely miss them most of the time. lol

Kilgore65
04-28-2005, 05:41 PM
lowdown, that is an excellent tutorial. You might consider compiling it into a word or pdf document for distribution!

Cloud_Cat
04-28-2005, 05:52 PM
Cheers, what a fantastic response. I have learnt an absolute boat load of info here.
Many thanks the help that everybody has offered.

Regards

AStotzer
04-29-2005, 06:22 AM
For those who have missed this, here is Wazoo's Charting and Targeting Tutorial:
http://www.paulwasserman.net/SHIII