Manual targeting is hard for me

[Dissaray]

Originally Posted by maillemaker

OK, first question:

I always approach ships being well in front of them, and I point my sub 90 degrees TO THEIR TRACK. This is NOT, as I understand it, the same thing as having an Angle on the Bow of 90 degrees.

Angle on the Bow, as I understand it, is the angle from the target ship (not their heading) to my sub.

So if my sub is 90 degrees to the target ship's HEADING, but they are a zillion miles away, the angle on the bow will be quite small, approaching zero the farther away they are. Angle on the Bow will not equal 90 degrees until they are directly in front of my sub, and then, of course, it's too late to be shooting torpedoes.

Is this correct?

You are right in so far as if you are perpendicular to the targets course and out in front of it the AOB will be smaler than 90. Set the AOB to 90 any way. Put the parascope to 00 degrees and then AOB to 90 and then lock in your TDC data. This should cause your gyro angle to read out some number, 045 for example. This number is the number of degrees your torpido is going to turn when you fire it. Now you rotate your parascope until your gyroangle reads 000, meaning your torpido will run in a strate line after you fire it; realy anything that is +/- 10 from 000 will work just fine. This will also adjust your AOB reading in your TDC, if you have it locked in properly, to a close estamate of what the AOB will be when the ship is at that point. If you rotate further to the ship it will tell you, more or less, what the current AOB for the target is. After you have all this set up you wait. Wait until your target comes into your scope. Where ever your verticle line in your parascope crosses your target when you fire the torpido should hit there, or relitivly close to it.

The way I understand it, I want to position my sub 90 degrees TO THE TARGET SHIP'S HEADING.

I then calculate the angle on the bow quite precisely using the protractor tool on the map, picking a point directly in front of the target ship, then ON the target ship, then ON my sub. This give me the angle between the target ship's nose and my sub. This should be the AOB, right?

This part I have down.
Steve

I think this method for calculting the angle will actualy get you closer to the angle on the stern, or the AOB for yoru position from the other side of the ship. I use that method my self, with a minor adjustment from your method, when I have time or visibility is too low for parascope observations. What you need to do in order to get an AOB that will work best for you is put your first protractor mark on the stern of the target ship, then extend to the bow of the ship and then finaly out to your sub. At least that is what works for me.

[maillemaker]

To get the speed via fixed line method (which, in my opinion, is the best way to go about doing it before you fire), you should let the ship pass across your 000 or your 180. Do not line your crosshairs up off of either of these numbers, as doing so makes the motion of your U-boat have a negative impact on the accuracy of the reading.

After doing this, yes, you need to then overhaul the enemy ship and get in front of it for a firing solution (assuming you want to shoot from an AOB of roughly 90.) This is how it was done in real life.

If I were in a convoy, then, I would be changing my speed about every 5 minutes, to easily thwart this.

And, of course, this assumes that the sub, having watched its target sail by, can catch up with it again.

Another method for gathering speed that was commonly used by the U-boat commanders was to simply steer a parallel course and match your speed so that the enemy ship stays on the same bearing (constant bearing method). If you are doing 6 knots on a parallel course and the enemy ship is staying at 72 degrees (for example) for a long time, then they are also doing 6 knots. If they move from 72 to 71, 70, 69... etc. they are going faster. Move your speed up and see if they stop moving. If they move from 72 to 73, 74, 75... you are moving faster than them. Slow down and try a lower speed.

This is believable.

If you look around, you can find joegrundman's tutorial for eyeballing the AOB of a ship. There are other ways to do it - mathematically, or with the attack disk (which comes in pretty handy - you can find it in the OLC GUI or in Hitman's upcoming [and totally amazing] GUI for GWX 3.0). However, the most common method in reality was to simply eyeball the AOB.

Finding the exact AOB is easy. The ship shows up on my nav map as a little ship-shaped silhouette if you zoom in close enough. All I have to do is use the angle tool to find the angle on the bow precisely.

Learn how to eyeball the AOB; it is the fastest method by far. Difficult to do from an extreme distance, but by the time you're close enough to shoot, you'll be able to tell easily. Second fastest method is the attack disk method.

I can eyeball the AOB pretty easily. I'm usually within 5 degrees of what I plot on the map.

What is OLC?

Steve

[maillemaker]

Put the parascope to 00 degrees and then AOB to 90 and then lock in your TDC data. This should cause your gyro angle to read out some number, 045 for example. This number is the number of degrees your torpido is going to turn when you fire it.

I don't understand. If my periscope is at 000 degrees (straight ahead), and the AOB is 90, why would the torpedo not run straight ahead?

Now you rotate your parascope until your gyroangle reads 000, meaning your torpido will run in a strate line after you fire it; realy anything that is +/- 10 from 000 will work just fine. This will also adjust your AOB reading in your TDC, if you have it locked in properly, to a close estamate of what the AOB will be when the ship is at that point. If you rotate further to the ship it will tell you, more or less, what the current AOB for the target is. After you have all this set up you wait. Wait until your target comes into your scope. Where ever your verticle line in your parascope crosses your target when you fire the torpido should hit there, or relitivly close to it.

I'm not understanding this at all, I'm afraid. Are you saying the ship's speed is irrelevant?

Are you saying all I have to do is set AOB to 90, lock my TDC at 000 periscope bearing, then turn the periscope until I have a 000 gyroscope reading, and then shoot when the ship crosses the reticule?

Steve

[Dissaray]

Originally Posted by maillemaker

I don't understand. If my periscope is at 000 degrees (straight ahead), and the AOB is 90, why would the torpedo not run straight ahead?



I'm not understanding this at all, I'm afraid. Are you saying the ship's speed is irrelevant?

Are you saying all I have to do is set AOB to 90, lock my TDC at 000 periscope bearing, then turn the periscope until I have a 000 gyroscope reading, and then shoot when the ship crosses the reticule?

Steve

Not exactly , no. The relitive bering, the number you see in the parascope along the top, is different from the gyro angle. The gyro angle is displayed in the three number display just below the notepad in the attack scope.

Here is a step by step break down of the proces I use that has been very effectvie for me:

1) Gather all needed data on target: Course, speed and a general distance.

2) Move undetected ahead of the target and take a position perpendicular to their course.

3) Put the attack scope at 00 relitive bearing, looking right out over the bow of your boat. Switch the TDC to manual input so you can enter the target data relating to speed and the general distance from firing position to target's course, the distance realy dosen't need to be accurate at all. Set the AOB reading to 90, eather starbord or port depending on which side of the ship you will be on when they pass.

4) Set the TDC back to automatic and make note of the gyro angle number while the attack socpe is at 00 relitive bearing. If the gyro angle number is between 000 and 090 move the attack scope to the left, if between 270 and 359 move the attack scope to the right, untill the gyro angle reads 000; again this number is below the note pad but above the tube selections butons in your attack scope and is labeled "Gyro Angle".

5) Wait for the target to move into view of the attack scope, without moving the scope, and fire your torpido once the part of the ship you want to hit, be it the bow, the stern, or the center of the ship or any other part of it, is crossed by the verticle line in your scope.

What this dose, effectivly, is draw a right triangle with the points being you, your target and where the torpido will impact the target. The hypotnuse in this case is the line of site between you and the target. The torpido will swim in a strate line from your bow, that is what the gyro angle is telling you, and if you have the speed of the target estamated correctly by the time the target crosses your bow the torpido will intercept it and explode, as long as it isn't a dud.

It seems like a lot to do in a short period of time but you can get it all done realy fast once you get the hang of it. After 4 or 5 patrols worth of attemped attack I was able to get it right just about every time. Now I can throw down a fireing solution and distroy targets inside a 1min of actual work relitivly consistantly, the attacks often take longer but that is generaly due to slow allied targets taking their sweet time geting into the kill zone.

Hope that helps.

[KL-alfman]

Originally Posted by maillemaker

What is OLC?

Steve

OneLifeCrisis
he's one of the vast band of highly talented modders, who made SH3 into this sim we all love unconditionally.

his mods can be found in the download-section.

[BillCar]

Originally Posted by maillemaker

If I were in a convoy, then, I would be changing my speed about every 5 minutes, to easily thwart this.

And, of course, this assumes that the sub, having watched its target sail by, can catch up with it again.

Most merchants have a top speed significantly under that of a U-boat's max speed, and if you're crossing the Atlantic, you can't afford to waste fuel through continuous evasive maneuvers. Moreover, I made an error in that first post - it is by no means necessary to do fixed line from 90 degrees. You can do it from in front of the merchant/convoy, very, very small angles.

This is possible because the angle at which it is moving does not affect the speed at which it crosses the line. There is no reason whatsoever to wait for a 90 degree AOB to do the fixed line method. If you don't want to catch up to it, take the AOB from in front, as it is coming TOWARDS you. You can take it as many times as you like and you'll still have several minutes before the ship passes you.

This is tough for some people to grasp, but it is true. You can do fixed line at 10 degrees AOB just fine, which means you can sit in front of it. If it starts speeding up, you can turn yourself and take the reading again. You can do this as many times as necessary, and you can do it while closing distance. Against a lone merchant, there is absolutely nothing that can be done to stop you. You can do fixed line right up until you're 300 metres away, and then a torpedo at fast speed is going to hit it pretty much no matter what anyway. It is by far and away the most accurate and reliable and immediate means of getting the speed. I can't recall the last time I outright missed a shot - usually if a ship doesn't sink, it's because the torpedo was a dud. Fixed line was also a favourite method of real-life U-boat commanders, for the simple reason that it works extremely well. Give it a shot, you'll be pleasantly surprised!

Speeding up and slowing down would work much better to thwart other methods - in the plotting example, if the ship moved slow/fast/slow/fast, you would wind up with an inaccurate reading based on the "average" speed. If it goes between 4 knots and 9 knots and you wind up figuring on 7.5 when it's actually gone back to 4 or 9, you'll miss, and you'll miss huge.

Since fixed wire method takes mere seconds instead of 3 minutes and 15 seconds, in order to thwart it within visual range, ships would have to be ordering a change in speed at least every minute or two. So no, speed changes every 5 minutes would not help you. Additionally, the fuel inefficiency caused by this would be unbelievable and wholly impractical (imagine driving across your continent going between 40km/h and 90km/h every 60 seconds), which is why this was not a commonly employed strategy in the actual Battle of the Atlantic. I can take a speed reading and fire a torpedo within 15 seconds of each other, if not shorter. So if you're a merchant doing 4 knots when I do my speed reading, you'd better hope you've throttled way up within 15 seconds (and since it takes a while for the speed to be gained anyway, you're probably still toast!).

Also, keep in mind that convoys can only go as fast as the slowest ship's fuel efficiency allows, and sometimes, that was very slow indeed (3 knots cross Atlantic was not uncommon on SC convoys).

Try the fixed line method out, and try it from a few angles - take multiple readings on one ship from multiple angles without getting spotted, and you'll see that it crosses the line in the same number of seconds if it is coming towards you, going away from you, or sailing right across your 000.

[Pisces]

So basically you are saying let the ship pass directly in front of my sub (bearing 000)???? Don't you then miss the shot? Or do I then, now having the speed, have to go race in front of them again for a shot?

Yes, in such a situation you have figured out the speed, but too late to make use of it.

What Snestorm forgot to mention was that you can turn your uboat towards the target until the bow or tail is right infront of the target. Then with the periscope line at 0 (or 180) you do the time measurement. (now your speed won't influence the result because it's also along the periscope center-line) Afterwards when you're done you can turn back perpendicular to the target track. Depending on how close you are you may not have the time to do this. But you don't need to do this when close to the target track at all. (where his bearing changes quickly) You can do it whenever you see an AOB between 30 and 150 and are quite far away. Like during the time you are trying to get ahead of him. Just temporarily turn towards him.

As for the number crunching. It's pretty 'simple'. Just divide target length in meters, by time in seconds. Then times 2 and you have knots. The accurate m/s-to-knot conversion factor is 1.944, which is 3600 seconds divided by 1852 meters. But you'll appreciate the simplicity of a nice round number I'm sure.

Are you saying all I have to do is set AOB to 90, lock my TDC at 000 periscope bearing, then turn the periscope until I have a 000 gyroscope reading, and then shoot when the ship crosses the reticule?

Exactly!! You seem to know how to do the right thing, or know what's what. Speed is the most critical value. As it defines directly the amount of lead. The only situation where speed is not important is when you fire a down-the-throat or up-the-butt shot. You'll have to be ON the target track for that. However, as soon as the torpedo is spotted the target can evade by just a slight coursechange. So not very desirable.

Uncertainty of the other values (AOB and range) can be neutralised or migitated by firing with 0 gyro angle AND shooting perpendicular to the target track. (which means the sub should also be perpendicular to the track) But now uncertainty of the speed has the biggest impact on lead. That is the life of a Uboat Kaleun unfortunately. But luckily the above mentioned speed measurement method is quite accurate. And even in a historical sense. They had a moving line in the scope optics that was synchronised with the gyrocompass. Any slight turn and the line moved against it.

[maillemaker]

Since fixed wire method takes mere seconds instead of 3 minutes and 15 seconds,

OK, what is the "fixed wire method"?

nevermind, I see it.

Steve

[ryanglavin]

Originally Posted by maillemaker

OK, what is the "fixed wire method"?

nevermind, I see it.

Steve

To be honest, I don't usually use the fixed wire method, as getting the 3

minutes 15 seconds is easily attainable at ranges above 9000 M, so you can

angle yourself to get a perfect shot while attaining its speed. The issue I have

with the fixed wire method is I have to get speed then do an attack run,

instead of doing both at the same time.

[BillCar]

As I mentioned above, you can do an attack run while doing the fixed wire method. I do it all the time. It does not matter what angle the ship is relative to you, so you can travel towards it from the front (almost head on), do fixed wire, and make your shot. If you need to turn more towards its track, well, hit hard rudder until you're roughly on the right track, and then fire. That adds a couple seconds, at most.

When I do it this way, it is rare for me to take more than a few seconds between getting the speed and firing the torpedoes. It is done in one run.

If approaching from behind, you're going to have to overhaul the target anyway to shoot from 90 degrees, so I don't see how that takes any more time, either. Briefly turn towards the ship. Take speed bearing(60 seconds or less, often times 20 or less). Turn the U-boat back to parallel course. Finish overhauling. Turn U-boat one last time. Fire. You're going to overhaul and close distance anyway, might as well get some immediate, up-to-date information while doing it.

[Joe Bob]

The things that have made all the difference to me is the AOB tutorial mentioned earlier in the thread and making a Submarine attack course finder.
I shoot from such short ranges that distance doesn't seem to matter.

As far as speed goes if a convoy is slow then its going to be 6 or 7 knots. I put in 6.5 knots and do fine. Again the short range may help there.

It may not be perfect but I have found it very useful to be able to make snap shots like that, particularly in poor visibility. Printing that AOB tutorial as a reference doubled my accuracy.

[maillemaker]

I have installed the hitman optics.

Question:

How do you toggle manual TDC data entry without going F6?

Steve