SOS: Captain needs tactical "Hunt" aid..

[Silverleaf]

Greetings,

This may turn into a long post, and if it does I apologize in advance.

I've been dreading writing this, having held off until I tried wrapping my eyeteeth around the tutorials on attacking with torpedoes in SH3. After reading through Wazoo's tutorial I was lost. Thought I'll try Hitman's Kriegsmarine circle, which while sweet looking (and I created a custom case for it), I've yet to understand all the nuances. So I turned to "The Hunt" pdf by Dantenoc, which has great images, much shorter, but again I'm scratching my head because I get a couple steps in to the tutorial, do something wrong and invariably wind up no closer than "Long Range" which translates into 10000 + meters when I search through the Attack Scope.

If I get any of these steps wrong, please let me know:

So, once a ship pops up with its little box, I click on it. I got the following: Slow, SSE

1) Drop to 1:1 real time ratio

2) Change my course to a general heading of SSE -or somewhere around 158 degrees - this way at least I'm heading towards the contact's path.

3) I use the protractor.
1st leg = From u-boat to Contact
2nd leg= From contact towards the reported heading - in this case 146-169 Degrees.

4) Find Contact Speed:
Slow = 6 kt or thereabouts.

5) Take ruler and plot distance:
Contact Speed (in kts) X 10 = Length of line

So I draw a line from the contact, on it's path out to 60 kms.

6) Use Compass and draw circle by clicking on end point of measured distance (in this case 60 kms) and draw a circle = 10 X (my intended speed for interception).

In this case, I'm close (still 15,000 meters away) so I will do 3 kt, staying submerged since it's daytime. I draw a circle 30 kms in size.

7) Where the circle intercepts MY current path is what I'm after here, yes?

If yes: Take Protractor:

1st leg: Click on center of circle, then on spot just bisected by the circle/my intended route
2nd leg: From end of Leg 1 to contact

So, I clicked on the circle center, and up to where the circle intersected my path, and back to the contact. I get 96 degrees.

http://i273.photobucket.com/albums/jj239/silverleaf1982/SH3Img26-12-2008_235850_799-1.jpg


If I plot a course for 96 degrees, I'm heading directly East - not anywhere near the contact's path. What am I doing wrong?

***

I just thought of something. That number: 96 degrees is from the current direction/heading my ship is traveling. Yes?

So, IF my current heading is 150 degrees, I need to turn the boat or plot a course that will eventually lead me 96 degrees to my right or to heading 246.

Is that at all correct? Or am I totally lost?

Cheers and thanks,

R.S.

[timbob]

I'm only a new SH3 player myself, but hit up on a good method that allowed me to successfully intercept 3 ships during my first patrol...

I get the ship popping up, with it's heading and time of sighting (this is important - I write it down). I put a mark where the ship is, and change course to a rough intercept course, and run up to flank speed.

Then I draw a line out ahead of the ship, on the correct course, and use the GWX "Speed Charts" that are up in the top left hand corner of the map screen. It'll tell me how far a ship goes doing 6 (slow) or 10 (medium) knots in 1, 2, 3, 4, 6, or 8 hours. Then I know where the ship is going to be, and what time it's going to arrive there.

Then I plot a new course to intercept, and use the "number of hours" reading at the end point of the course to make sure I arrive in time.

If I'm way running behind and am way too late, I do a quick mental sum, and work out whether I need twice as long, or three times as long to get ahead of the target, extend their course line to adjust, and adjust my course (and sometimes speed) to suit.

I'm not sure what the exact procedure would have been on board a sub, but the mental arithmetic, using the charts available method seems "right" to me.

[meduza]

Silverleaf, I think you took a wrong turn at step 7 :D
When you draw the circle, look at the point where it intersects a line connecting your position and the target (the protractor leg you made in step 3). Pick up the protractor, draw a line from the center of circle to that point I mentioned above, and to the target. Note the angle of the protractor.
Take the protractor again, with that same angle, from the target into your boat, towards the target's path. Where that second leg intersects target's path is th spot you will intercept it. That second leg is your course. Use the bearing tool to measure it, or make a waypoint.

But if you follow that course at the speed you used to calculate the intercept point, you will reach it at the same time as your target. Calculate your speed to reach the point about half an hour before the target to prepare your attack.

Also, for "slow" targets use 7kts, not 6, as this is the maximum speed they could go. For "medium" it's 12kts.

Hope this makes sense. If not, ask. :D

[Pisces]

6) Use Compass and draw circle by clicking on end point of measured distance (in this case 60 kms) and draw a circle = 10 X (my intended speed for interception).

In this case, I'm close (still 15,000 meters away) so I will do 3 kt, staying submerged since it's daytime. I draw a circle 30 kms in size.

7) Where the circle intercepts MY current path is what I'm after here, yes?No! I'm afraid you made a mistake at point 7.

Take a good look at step 5 again in Dantenocs procedure: http://www.subsim.com/phpBB/viewtopic.php?t=48026&postdays=0&postorder=asc&start=0

The (ownspeed)circle should cut the bearingline from the uboot (initial position) to the target (initial position). It's those 2 protractor legs between the target icon and the number 97 in your picture. You chose a ownspeed of 3 knots, probably because you wanted to stay submerged. However, you should first have found out what was REQUIRED, THEN choose your speed: the speed that is required or faster. As you can see the 3 knot circle never even touches the bearing line to target (those 2 protractor lines mentioned above). If you used an intercept speed of 5.5 knot the circle would about touch the bearingline and it would be the absolute minimum. Choose a higher speed to get an intercept course that is turned sharper towards the target.

HOWEVER, you GUESSED his speed to be 6 knots. It could be that it had a speed between 7 and 8 knots. Then you would end up behind the target. Personally I assume their speed is worst case (slow: 7.5 knots; trust me, if it was 8 knots it would be reported as medium speed) and wait for it to close up on me, or set course to meet when I arrived on his course track well before him (outside visual or hydrophone range).

I don't see where you got the idea you are 15km away from him, the picture shows you were at approximately 35km initially. Definatly a surface! intercept!!!

If you then follow the steps as you did you should arrive at the propper intercept course.




Small tid-bit
The initial range to target seemed to be about 35 km. For this reasonably close range you may want to use smaller multiplication factors (the 10 you use), something like a straight 1knot-to-1km or 1knot-to-5km. 10km makes the intercept triangle larger than the real distances. This could require the bearingline to target to be extended beyond your initial position to make the ownspeed-circle cross it.

[Pisces]

Here's a picture someone around here (Kylania by the looks of the link) once made, which sums it up pretty nicely in one go:

http://www.kylania.com/sh3/Intercept_Plotting.png

[Silverleaf]

Timbob,

Ok, you've given me more to think about. I like it and am always looking for more tactics!! :p

Meduza,

Your great reply led me to do more research and re-read the tutorial a few more times. :damn:

Pisces,

I wasn't completely following your post, though I went back and watched a couple videos. The light as they say hadn't completely come on. Then you added the excellent image. That completely cleared it up.

I shall report my next attempt within 24 hours, if we survive the current barrage of Depth Charges. :up:

Follow-up Question:

Since it's daytime in this situation, why should I be on surface for an approach?

Wouldn't it be better to stay submerged, undetected and not give the target any reason to alter course?

I'm going at this from the standpoint that my Sonar guys been terribly late/non-existent with reports. In three instances (I can think of) I've personally spotted a contact at medium range closing fast using the attack periscope and then lo and behold Mr. No Ears himself screams it out.

What's the general opinion on such a situation?

Thanks guys - you've been a huge help. ^5ss

[meduza]

I shall report my next attempt within 24 hours, if we survive the current barrage of Depth Charges. :up:
Good hunting, Herr Kaleun! :arrgh!:


Since it's daytime in this situation, why should I be on surface for an approach?
Because of the speed. Unless you have Type XXI, your top speed is inadequate to intercept anything but a slow and close target. And you can maintain top speed only for a limited period of time.

Depending on a situation, once the target is in visual range you will either submerge and approach for attack, or estimate its course and speed, get out of visual range and start an overhauling maneuver that will lead into the position for submerged attack.

I'm going at this from the standpoint that my Sonar guys been terribly late/non-existent with reports. In three instances (I can think of) I've personally spotted a contact at medium range closing fast using the attack periscope and then lo and behold Mr. No Ears himself screams it out.
Give your sonarman the Radioman qualification, and he will do his duty much better. Consider using the hydrophones yourself, you can hear propeller noise from greater distance than your sonarman can.

[Silverleaf]

Meduza,

Ok, totally understand. The quick replies really help.

And thanks, I shall attempt to make the Fatherland proud.

:lurk:

[Pisces]

Since it's daytime in this situation, why should I be on surface for an approach?

Wouldn't it be better to stay submerged, undetected and not give the target any reason to alter course?

I'm going at this from the standpoint that my Sonar guys been terribly late/non-existent with reports. In three instances (I can think of) I've personally spotted a contact at medium range closing fast using the attack periscope and then lo and behold Mr. No Ears himself screams it out.

What's the general opinion on such a situation?

Thanks guys - you've been a huge help. ^5ssThe target won't be able to see you when you are more than 16 km apart (or 8km, depends on which visibility range mod you have active). If it's bad weather or night it's even less. So if you start your intercept when your are 35 km apart you can close to 20 km before he has any chance of seeing you. Why close this distance slowly? Then he will have more chance of reaching his next waypoint before you find him. And then you might loose him due to his course change, invalidating your intercept.

Destroyers might be different though, since they have hydrophones too and might detect you passively further out if they care to listen. I'm not sure if they are that sensitive though at such ranges, and it might depend on what year you are in. I'm still early years, so no Uber-DDs yet, if at all. It's just something that came to mind in case you go after convoys.

Don't trust your sonar crew in reporting him. Listen yourself! You'll start to hear ships as then enter a 34km range, alot earlier than the crew. You might have to pump up the volume. Your speakers as well as the ingame amplifier knob on the hydro console.
As soon as your watch crew get a visual either submerge or turn to a parallel course and match speed (you allready know his general course/speed from the map report) to avoid getting too close. From then on you can start to think about your next plan: refining his speed and course.

[Letum]

Everything has been answered, but just in case, here is my take:

http://www.b3tards.com/u/57a418c694bc7c6296b3/diag1.jpg

i) U-69 has a top speed of 17knts.
ii) U-69 gets a report of a convoy/taskforce/lone ship. In this case its a task force at 14knts.
iii) Draw a line along the target's heading.
iv) Draw a line from the target to U-69
v) Make a mark 14km* along the target's path. If the target was going at 7knts then the mark would only be 7km along the targets path. 8knts would equal 8km etc. etc.


*(The mark can be 1.4km or 140km, it matter as long as you keep to the same scale with all other distances)


http://www.b3tards.com/u/57a418c694bc7c6296b3/diag2.jpg

vi) Now use the compass tool draw a circle starting from the marker you just made. The radius of the circle should be equal to U-69's to speed. In this case the circle has a radius of 17km because U-69 can go 17knts.


http://www.b3tards.com/u/57a418c694bc7c6296b3/diag3.jpg

vii) Now draw a line from the middle of the circle to the point on the circumference of the circle that circumference intersects the line from U-69 to the target. In the diagram this line is labeled "(3)".
ix) Now measure the angle between the new line and the line from U-69 to the target. We will call this "ANGLE A" it is about 35deg.


http://www.b3tards.com/u/57a418c694bc7c6296b3/diag4.jpg

x) I have cleared up some lines we don't need any more.
xi) Finally use the protractor tool.
Make the first click on the convoy.
Make the second click on U-69.
Measure the angle so it is the same as "ANGLE A".
xii) If you follow this new line you will arrive exactly at the same time the target does. If you want time to prepare for the target, then add a few degrees to "ANGLE A".


The advantage of this method is that it gives you the shortest, fastest target intercept.