Manual Targeting - Periscope Bearing
 

I am new to submarine simulation and so I'm on a steep learning curve. I've set up a simple "practice" mission to check out different things. I put a simple "dead in the water" freighter pointed on a heading of 90 deg with my sub due south at periscope depth 1000 yds away with a heading of 0 and bearing of 0. I set the AOB at 90 degrees (perpendicular). Once I fire my first torpedo the freighter starts up but continues his 90 deg heading (I've dummied him way down). What I just noticed is that if I follow him with my periscope until he is at a bearing of 20 deg, leave everything else alone (no PK, 90 deg AOB, 0 speed, but set a new distance) and fire a torpedo, the torpedo tracks due north and does not turn at all. I thought that even in manual targeting mode the torpedo would track to the bearing that the periscope is looking. Is this not the case? Is there no true "kentucky windage" firing mode that just shoots in the direction you're looking?

Thanks for any help.

CajunRon,
What may have happened is that when you first entered the data into the TDC, the target's speed was 0kts. Once he gets underway, if you do not enter a new speed (i.e. dial it in, then click "send to TDC"), the TDC still assumes the target has no speed and is due north of you.
If you did enter a new speed - and check on the position keeper when it shows you the intercept range and target speed - it may be an issue of having to update the PK but I don't think that should matter here.
- dmlavan

The torpedo could have also under run the target. 1000 yards is pretty close and won't give you a lot of time to use external camera view, but if you set the torpedo to slow speed, you should be able to watch the underside of the target and see where the torpedo tracks.

Are you running any mods or is it SH4 v.1.4 vanilla?

Just turning the scope doesn't update the bearing in the TDC. You have to click the red button to send the new scope bearing to the TDC.

Another thing to keep in mind is that by the time the target is 20 degrees to your right, his AOB is no longer 90, its 110.

If the target speed is set to 0 on the TDC the torpedo will go where you are looking, provided you have clicked the button to send your current periscope bearing to it.

If the target speed is greater than 0 the torp will lead the target so it hits, so it won't go down the bearing you are looking.

You're at step 1
 

Your job of entering the data into the TDC is flawless. Did you enter the speed of the target as well? Good.

Now at the moment that all the information is correct, AoB, bearing, distance and speed, press the Position Keeper button. This will track the target for you. In practice, hit the position keeper button first, then enter the target speed, AoB and bearing/distance in that order.

Now your TDC/PK will track your target and you can shoot any time and hit him assuming he doesn't change course or speed, even if you shoot with the scope down!

If you think about it, a full-time hookup between periscope bearing and TDC would render the American system useless.

No Bearing Info to TDC then
 

Thanks to all for the responses. If the periscope bearing is not sent to the TDC, this means that the TDC does not receive any bearing to target information directly. If that's the case, the only thing that's telling the torpedo to turn is the AoB and target speed. And these are very difficult to get quick estimates on. Is that correct? If so, getting off speedy but accurate shots on multiple targets or targets which are continuously changing course and speed seems like it would be next to impossible. (at least for me anyway)

That's exactly right. The Attack Data Tool sends the AoB and target Speed, and these set the gyro angle for the torpedos (the Spread Angle will also, but I'm assuming it's set to zero). If you watch the small white arrow on the Position Keeper you'll see it move port or starboard with the AoB or Speed input.

This is why one of the arguments for close firing range (less than 1000 yards) makes good sense.

Difficult ... but not impossible.

You can increase your chances of getting a hit by decreasing the effects of your errors to the TDC. You decrease the effects of error by setting your fish to run fast and firing at close range (800 yards is good ... 600 yards is better ... inside that and you run the risk of not giving your torps time to arm).

You should also keep the convoy's base course set in the TDC. Merchants are less likely to make drastic changes in heading (after an attack is in progress) ... consequently, they make the best targets if you plan to attack more than one. And, if you make all your attacks quick enough (using the same base course and speed for all your targets), the only adjustment you need to make is for bearing and distance.

:yep: Or, you could use the O'Kane method and target overlapping ships or those close enough together so that two or more pass through your aim point in a short period of time.

It's important to note that the TDC always has a range, bearing, AOB, and speed dialed in. They have default values when you leave port. If the PK is off, it remembers the last entered value for each one. If the PK is on, it evolves the four values over time. Anytime you fire a torpedo the gyro angle is set based on all four of these values.

It's true that the TDC does not support generating solutions for targets that are not at a constant speed and course. However, with practice you can make snapshots on these targets at close range. One way is the "kentucky windage" shot you mentioned where you lead the target by eyeball.

I hate to disagree with an expert!
 

For any target whose AoB is not 0º or 180º, the American TDC needs three parameters to complete a solution: target speed, AoB or target course AND target bearing/range. If you want to be picky (bearing and range are sent with the same input through direct input from the periscope when you press the range/bearing send button) you can separate range and bearing as I do with the Dick O'Kane technique, but we're talking textbook TDC technique here.

Angle on the Bow and speed are useless by themselves because the torpedo must be fired along a bearing line to the target. The gyro angle is the difference between the sub's heading and that bearing line. Now the torpedo track will also be corrected from that bearing line because of target speed and range in order to properly lead the target so torpedo and target attempt to accupy the same space at the end of the run and we get a kaboom.

So under no circumstances is Angle on the Bow and target speed enough data to shoot. In fact your TDC will tell you there is no solution for torpedo #x if you push the fire button.

Rather than confuse you I'm recommending you to the WernerSobe Advanced School of Submarine Attack Tactics (WASSAAT). I'm sending you to my links in Werner's thread because at last report Werner's quit working. These are still HIS videos, not mine. They're the best you will find. http://www.subsim.com/radioroom/show...0&postcount=82.

Classes begin when you arrive (you're a VERY important person). While you're there, visit my seminar on the Dick O'Kane attack method, which simplifies technique a bit and allows you to aim each torpedo for a specific spot on the target. http://www.subsim.com/radioroom/show...6&postcount=67. Time spent reading posts in Werner's thread will make you a great sub skipper.

Enjoy, then hide, hunt and kill!:arrgh!:

Fantastic information
 

This is fantastic information. I have downloaded the WernerSobe videos. The are truely the best and by far the most helpful single source I've come across. These and the information you all have provided is making it all come together.

Where can I find the radial grid for the attack map that he uses in his video? I've search the mods list but can't find it.

Thanks tremendously for all the help.

*knock knock!*

Delivery for you, sir! Pick it up here!

...
 

Is SUBSIM a great place or what?:rock:

Ask and you shall receive. Just for fun, sometimes you get what you need!:rotfl:

Well, for some strange reason, I can't get a particular scene from Monty Pythons And The Holy Grail out of my head now...must be the wording I used...and the arrow sticking out of me! :rotfl:

Dr Beast or anyone, is it possible to get this bearing mod to fit my res at 1600x1200 http://www.subsim.com/radioroom/showthread.php?t=110133 i would love to use this but not sure about fitting my resolution, anyone no.