OK, now I can hit stuff! :)

I am using the "fixed wire" method.

Here is how I do it.



1) Point periscope about 10 degrees in front of target. Press "=". This brings my sub's heading to where the periscope is pointing.

2) Once submarine has stopped turning, center up periscope on sub bearing 000. Your vertical crosshair should be in front of the target ship.

3) Wait for the target ship's nose to touch the vertical crosshair. While you are waiting, identify ship in recognition manual and determine ship length. When the target ship's nose touches the vertical crosshair, start stopwatch.

4) Wait for the target ship's stern to pass the vertical crosshair. Stop stopwatch.

5) Use this forumula to determine speed:

(1.852 * ship length in meters) / time in seconds

6) Go to the TDC.

7) Turn on manual data entry.

8) Set Angle on the Bow (AoB) to 90 degrees starboard or port, depending on whether you are on the starboard or port side of the target ship. It does not matter what your actual AoB is.

9) Dial in the target ship's speed.

10) Turn off manual data entry on the TDC.

11) Return to periscope view. Turn the periscope until the gyroscope angle is 000.

12) Wait for target ship to travel across crosshairs. When ship is in vertical crosshair, fire torpedo!

Note: If you don't want to wait for the ship to hit the vertical crosshair, you can turn the sub left or right to speed up the process. It is advisible not to fire until your sub has stopped turning.

WHAT I HAVE LEARNED.

First, The simulation is a lot harder this way! :)

Second, the simulation becomes much more an exercise of pointing your submarine instead of pointing your periscope.

Whoever changed my thread title, manual targeting still sucks! :)

Steve

Great stuff! You'll have a lot of fun with this.

For Hitman's optics, you need to hit CTRL + T to lock and unlock the TDC. I forgot to mention that.

Good hunting!

Maillemaker:

Congratulations on getting better at this.

But at step 8 it actually does matter what the real AOB is. If you didn't turn back to a course that is perpendicular to the tartget course you need to set to the AOB as seen at that point. Only set the AOB dial when you actually are facing a direction that will get an AOB of 90 when the target passes the periscope view. You may have succeded because the actual AOB was not that much different but other situations might have resulted in a miss.

At step 5 the number should really be 1.944 or for simplicity sake 2. The number 1.852 is not correct. Close enough, but not correct.

When in doubt, fire a spread!

Not sure if this has been mentioned, but don't forget to open the tube doors before you press the fire button. That one second is a really big deal at longer ranges.

Something that I don't understand with the fixed wire method : Why you have to put your sub at bearing 000 to do it ? If you put only your scope at 000 whatever the position of your sub, it doesn't work as well ?
I really don't understand the importance of the position of the sub in this case : what the scope show you is the same if the bearing of the sub is 000 or other, if you're stopped of course ! Perhaps this last detail is the ansewer of my question ?

Ahah! I see now. I always attack from perpendicular to target heading so I did not notice.

I guess what I was thinking is that while you "shoot the line" it does not matter what the AOB is.

I like this fixed wire method. You can get the target speed in about 30 seconds, all while moving in on your target. Once you have the range, just turn left or right 20 degrees and wait for them to cross your crosshairs!

Steve

Yes, you can do it with the scope at any position if you are stopped. But most people are going to be moving, and I don't like to stop my sub while moving in on a target. To point the scope at 000 or 180 negates the movement of your own sub by keeping everything on the same axis.

@ maillemaker:

Yep, that is indeed the beauty of the fixed wire/ fixed line method!

How does this all work when firing the stern tubes?

Steve

For fireing a stern shot the steps are all basicaly the same but you line up the shot so the target is behind you rather then in front of you. The AOB reading is for the oposite side of the ship when conducting convoy attacks from what it would be for the forward tubes, but only when attacking from within the convoy.

What Dissaray said: you'll take your fixed wire with the periscope at 180 instead of 000. It's the exact same process.

With the fixed line method you are sort of making a wall in the sea with your periscope line. Or something like a finnish-line, except [b]it doesn't matter when[b] the target crosses it, but how long it takes to cross it. You want this imaginary wall to be fixed in the world. Since a moving wall (sideways) is messing up the measurent.

This wall (the periscope line stretched into the distance) moves sideways when you are not looking along the bow-stern line and have a bit of speed yourself. If you are looking in the same direction as you are moving then your speed doesn't matter. You can go reverse or flank forward if you want and the target takes the same time to cross it. (well, flank speed is quite a bumpy ride and the bow starts to roll on the waves, so you better not exagerate)

If you are looking to the side of where you are going, some of your speed is directed along the periscope line, but some of it is also pointed away from it. This sideways component is messing up your speed measurement. Let's say you are traveling with a speed of 6 knots. And you have the periscope pointed at 10 degrees from the bow (010, or 350). This makes the imaginary wall from the periscope line move sideways with about 1 knot. And so too will the real target speed show 1 knot too low or too fast. (depending if the movement of the wall was against or with the movement of the target)

So the AOB is reversed for stern shots?

Steve

Only if you are attacking a convoy from in between the coloms of the convoy. In that case you would have, for example, if you have an AOB set to 90stb for your forward tubes you would have to switch it to 90port befor you switch from firing your forward tubes to your aft tubes. I forgot to do this one time and acsidentlaly hit the ship behind the one I was aming for.

Other than that you make an aft shot just like any other shot, with exception of having the back end of the boat facting the target and not the front end.

OK, yes, I can see if I were in the middle of a convoy obviously the AOB would change as you are on the starboard of some ships and port of others.

I was talking only about a single ship attack. So stern shooting is no different than bow shooting then. Good.

Steve

Thanks BillCar, very interesting method this fixed line, more simple and more accurate than the 3 mn 15.

Another important point for the manual targeting is the choice of the torp's proof. I had a lot of missed in bad weather conditions before I understood what happened.
Recently I fired two torps (impact, same proof) at a medium cargo in rough sea and wanted to take care of the proof, I fixed it 3 meters up as I would do in normal conditions. First torp, nothing, the second hit around the middle of the ship, means fired solution was perfect.
I used the external camera to see what happened : only one hit at the extrem limit off the hull !

I used the fixed wire method to make stern shots last night with no problem.

Fixed wire is great. The only drawback I see (of course, this is true for any method) is that you need reasonably good visibility in order to track your target far enough way to get its speed so you can turn and attack before they are right on top of you.

Steve

If they're far away and visibility is unsatisfactory for making an identification, you use the constant bearing method to get their speed (or you can do the 3m15 method, but constant bearing is equally accurate and takes less of your time up with plotting). Then when you're reading to make your attack run, you can do fixed line on your way in to reconfirm the speed reading you took from the constant bearing method. :up:

Hmmm.
Just got back from a patrol, and see I missed all kinds of fun on this thread.

With all the contributions, it realy turned out to be a great thread.

And more importantly, a highly productive one for Maillemaker.

Great job guys!