Guides and Training

[Spectator]

Rockin Robbins encouraged me to post in this thread, so here's my take on a vector analysis attack as seen here on the last picture

I made a video that shows the whole process from target spottet, till target on crash dive ->

(Don't get confused that I chose 90° for my approach, you can do this with any angle! It's not limited to 90° like seen on the Dick O'Kane Method picture. This is the method in the last picture, which of course is similar, but there are some important differences.)



In case the video leaves some questions, here's what happens, step by step:

Determine the target's speed: There are many ways to do this. The one I choose in this video is the so called "3 minute rule". You mark the current position of the target on the map, then you wait 3 minutes and mark again. The distance beween those two marks in yards represents the target speed. In the video the two marks are 900yds away from each other, that means the target runs at 9kts.

(In the video the "no map contact update" realism setting is disabled, so the marks are pretty straightforward. However, usually I have that option enabled, so there's no contact updates on my map. It's still pretty easy to mark the target on the map without those automatic updates, you should try it, it's no big deal and adds to the immersion if you like micromanagement. All you have to do is to get target bearing and distance and draw it on your map, maybe I'll make a tutorial Video about that too )


Planning the approach: After determining the speed with the 3 minute rule, you have 2 marks on your map, let's go ahead and use them for another task. Take out your ruler and draw a line that crosses those 2 marks, and there's your target track. To increase accuracy you can add some more marks before you draw the line, or add them later to verify your estimation of the target's course.

In the video I drew a line that's 9nm long on the map. The reason I did that is, that it gives me another piece of information without me having to calculate, ... a vessel running 9kts will travel a distance on 9nm in exactly 1 hour, so no I know exactly where the target will be 1 hour from now. (You have to make sure that the 9nm are measured between the target's current position and the end of the line if you chose to do it like seen in the video. Of course you can use other tools to measure and mark those 9nm on the map, that's up to you )

Now that i know where the target will be, I take out the protractor and draw a 90° angle for my approach at the 9nm point. I want to be within about 700yds of the target when I fire my torpedoes, so i make sure to plot my course accordingly. Make sure that, if you have a similar setup on the map, concerning your position relative to the target's position, that you don't get too close to the target while approaching your "hunting spot" on the surface. Better run faster a bit further away to get out of sight (I ran at flank on a parralel course until i intercepted my 90° approach line just to make sure. Of course flank isn't really necessary, but I won't get into detail on those calculations in this tutorial)


Getting the lead angle: Now we are at ~00:50s in the video, it's time to find out the lead angle for the attack. The lead angle is where your periscope will point to later, while your ship points to the impact point, the 9nm "hunting spot" in this tutorial.

What you do now is, you draw a line from the impact point towards the target. The line's length is the target's speed * 100 yards, so in our example it's 9kts * 100yds = 900yds. Then you draw a line representing the torpedo speed of 46 kts (4600yds) towards your boat. The last stept is to measure the angle between the torpedo line and the imaginary line from torpedo line end point to target speed line end point. If that sounds too cryptic, check it out in the video, I hope that will show it better.
In this tutorial with an approach angle of 90°, a target speed of 9kts and
mk14 torpedoes on high speed setting running 46kts, our lead angle is 11°.


Setting up the shot: Make sure your boat is properly aligned, so that your bow points at the impact point. What follows now is always the same process, no matter how far you are away from the target (the closer the better in terms of accuracy, therefore i chose ~700yds)

Go to the periscope, make sure your periscope is at 0° and then enter the following data into the TDC:

- AoB = 0 -> send
- Speed = 0 -> send
- Distance = max (turn the distance wheel to the right, should give you about 1200yds in the tdc after you send it) -> send

Now turn your periscope towards the target until you match the lead angle, in this example 11° to the left which means you have to go to 349° (360-11°). If the target would cross your view from right to left you would point your periscope at 11°.

Set up your torpedoes to run at high speed (46kts). You can also do this with slow running torpedoes or totally different speeds if you have some fancy modded ordnance, just use the proper yards representation when determining the lead angle.

You won't need to touch the gyro dial! Your "spread" will be archieved by the target travelling along it's course, you'll see further down.

Don't forget to open your tubes before you shoot, the time it takes to open them will mess up your solution, so better open them early.

That's it for the Setup. Leave the position keeper OFF, you won't need it.


The moment of truth: When the target is close to your lead angle - I usually monitor the target with sonar until it's about 10° away from the lead angle, so in this example I raise the scope when the target passes 339° (not sure if I did that in the video, might be a bit later there, don't get confused ).

Now all you have to do is, wait for the target to pass your scope and fire at the parts you want to hit. What I usually do is, I shoot the first torpedo as soon as the bow is in the center of the scope, then wait for the center (usually between command deck and funnel for a merchant) to fire #2 and finally i put a third one under the last 3rd of the target (usually that's the stern mast)


And that's it. If everything went right, the target should be on its way to some deep sea exploration.


//sidenote: 90° isn't a good choice for this method, especially with mk14 torpedos. Those fish tend to turn out as duds very often if you hit the target at 90°. Chosing a steeper angle reduces the dud risk, and since this method's advantage is the fact that you can choose any approach angle you want, you should use that.

[rsvette12]

Wonderful stuff guys, thank you.

Regards, Rich

[Rockin Robbins]

Best illustration of a vector analysis attack so far! The fact that you did choose a 90º angle to the target track shows the relationship the vector analysis has to the Dick O'Kane attack. But as you say, the beauty of the vector analysis attack is that it is just as easy to do at any angle to the track.

Note that no calculators or pieces of paper and writing instruments were harmed here. Everything is done within the game and there's not a calculation to be seen.

Also note that the TDC and the PK are not used here. (You do need to check that the speed is set to zero and/or the AoB is set to zero or 180) No Easy AOB mod came anywhere near this attack. It can be done in a U-Boat as well as a fleet boat with equal ease.

So, if it's that good, what are the weaknesses of the vector analysis attack? If you compare it with the Dick O'Kane and John P Cromwell attacks, it has only one weakness: you MUST know the correct speed of your torpedo. If you figure 46 knots for the fast Mark 14 and accidentally leave it on the 31 knot slow speed, you miss by a mile. In the other two constant bearing attacks the TDC remembers the speed of the torpedo and figures the lead angle for you.

But that's it: the only gotcha in a vector analysis attack. I highly recommend it! Thank you, Spectator, for the best tutorial I've seen on the vector analysis attack.

[Kapitan Soniboy]

Hey

I downloaded the Cromwell attack and the Dick (by god!!) tutorials. Want to say thanks because this is really fun to do. Still have some trouble with the Cromwell attack method though, but with a little more practice it will turn out good in the end. Very satisfying to sink a ship with sonar only.

Did they really manage to sink enemy ships without ever raising the periscope?? I mean really... at that time?

Thanks

(sorry if it's anything wrong with my english)

[Rockin Robbins]

Originally Posted by Kapitan Soniboy

Hey

I downloaded the Cromwell attack and the Dick (by god!!) tutorials. Want to say thanks because this is really fun to do. Still have some trouble with the Cromwell attack method though, but with a little more practice it will turn out good in the end. Very satisfying to sink a ship with sonar only.

Did they really manage to sink enemy ships without ever raising the periscope?? I mean really... at that time?

Thanks

(sorry if it's anything wrong with my english)

Your english is great!

With the Cromwell attack, the main hazard is that the target sees the approaching torpedoes. Then he only has to turn 45º into the torpdoes to avoid them. During the daytime, this is a good time to use Mark 18s. At night use the fastest torpedo you have.

At the beginning of the war, doctrine was that all shots were to be taken with sonar only, as it was thought to be too dangerous to raise the scope in close combat with the enemy. In practice before the war they did have success hitting single ships that way.

However in the real war, a single target was pretty rare. Even in the game, it's difficult to use sonar only in a crowded situation. What happens if you ping one target on your first observation and another for your second? You've just created a fictitious target and will hit nothing! There are many ways to miss using sonar only and our submarines found most of them.

Then successes started to come when aggressive younger commanders who were willing to buck the system and use their periscopes to obtain more accurate targeting information. They obtained several times the hit ratio.

As a matter of fact, after the advantages were discovered, Admiral Lockwood made periscope attacks official policy. Even then the real life ostriches (we don't just have them in the game, they were a real life problem) had to be rooted out and relieved of their commands when they were unwilling to take necessary risks to obtain success. Later, Lockwood had to go through round 2 of removing ostriches for those captains who insisted on remaining submerged all day, ruining their combat readiness during their nighttime recharging ritual.

[Kapitan Soniboy]

Originally Posted by Rockin Robbins

Your english is great!

With the Cromwell attack, the main hazard is that the target sees the approaching torpedoes. Then he only has to turn 45º into the torpdoes to avoid them. During the daytime, this is a good time to use Mark 18s. At night use the fastest torpedo you have.

At the beginning of the war, doctrine was that all shots were to be taken with sonar only, as it was thought to be too dangerous to raise the scope in close combat with the enemy. In practice before the war they did have success hitting single ships that way.

However in the real war, a single target was pretty rare. Even in the game, it's difficult to use sonar only in a crowded situation. What happens if you ping one target on your first observation and another for your second? You've just created a fictitious target and will hit nothing! There are many ways to miss using sonar only and our submarines found most of them.

Then successes started to come when aggressive younger commanders who were willing to buck the system and use their periscopes to obtain more accurate targeting information. They obtained several times the hit ratio.

As a matter of fact, after the advantages were discovered, Admiral Lockwood made periscope attacks official policy. Even then the real life ostriches (we don't just have them in the game, they were a real life problem) had to be rooted out and relieved of their commands when they were unwilling to take necessary risks to obtain success. Later, Lockwood had to go through round 2 of removing ostriches for those captains who insisted on remaining submerged all day, ruining their combat readiness during their nighttime recharging ritual.

Wow you sure know alot! One more thing. I tried diving to 140 -150 feet the first time I wanted to perform a sonar only attack. The maximum depth for torpedo launching is something like 150 feet (I think). I experienced some problems when trying to figure the enemy ship's course and speed. I recieved false information about the target's range. Do you think it has something to do with the depth I was in (thermal layer?) ?

[Rockin Robbins]

I doubt it. Sonar ranges are not exact. You have to take several readings and kind of average them by gut feeling. Of course, while you are taking the ranges, the range is changing, adding to the challenge.

Sonar only can never be as accurate as periscope guided and radar guided attacks. And we've got it easy! Our sonar bearings are exact, where on the real boats there was a 2º slop factor where it was impossible to perfectly center the sonar bearing. I'm unclear whether that was plus or minus two degrees or two degrees total error. It doesn't matter. It means sonar only was more difficult for a real submarine than it is for us.

In the game, make sure your sonar man is following and announcing the target bearing. Put your sonar on that bearing when you ping and don't forget to send bearing and range separately. In the stock game you can use the switches on the panel. For some reason in TMO and RFB you need to use the button bar to send range but can still send bearing from the panel. Be sure you send both to the TDC! I just use the button bar to send both and remove all doubt.

You're right. The sonar only method should never be your default method. It is mostly a demonstration exercise that gives tremendous satisfaction when it works properly. However, in real combat it is VERY useful in heavy fog or rain, where you can get darned close and blast 'em from nowhere.

[Kapitan Soniboy]

Thank you once again. I play TMO since it add so much more fun to the game. I followed every inch of your tutorial and it worked great but I forgot that you were playing the stock game when making the tutorial. However, it worked in the end and it was very fun.

Right now I'm having a Gato in mid 1943 but I find destroyer escorts too easy to evade. Does Japanese ASW techniques improve later in the war? (last question)

[Rockin Robbins]

OOOOOOOOOOOO YEAH!!! Japanese escorts are nasty, nasty from the last half of 1944 on. I just attacked a nine ship convoy guarded by four assorted escorts in the South China Sea just north of Formosa. It was stormy conditions, so sonar wasn't the greatest, but I only had 150' of water and no thermal barrier to deal with.

Three night attacks over two nights and I never got a shot at the merchies. I did sink my first escort in a surface gun battle (is there any other kind?). I consider that an impressive achievement in TMO. He couldn't hit the broad side of a barn in the rough conditions and I played Jack-in-the box with him. I'd pop up, take four shots or so, submerge and pop up again somewhere else. Between the deck gun and 40mm I finally sank him. Didn't do any good. The remaining three drove me off again. What a battle! 48 hours of pure mayhem.

[Kapitan Soniboy]

That's awesome! I would never challenge a Jap escort to a gun battle! But I did have to blow ballast once since my boat kept sinking after a severe depth charge attack (S-boat of course) and a big gun battle happened on the surface and my little S-boat got pounded in the end... (Now I think it's easier to evade with my Gato)

I raised my SD antenna while at periscope depth and it was able to detect ships (?). I thought the SD radar could only detect aircraft and there is no information about the SD radar on Wikipedia. Do you know anything about it?

[Rockin Robbins]

SD didn't detect anything below a certain number of degrees elevation, so would have had a tough time reporting surface ships. It's a game glitch that we have our radars combined and kind of mashed together.

[DigitalAura]

Originally Posted by Spectator

Setting up the shot: Make sure your boat is properly aligned, so that your bow points at the impact point. What follows now is always the same process, no matter how far you are away from the target (the closer the better in terms of accuracy, therefore i chose ~700yds)

Go to the periscope, make sure your periscope is at 0° and then enter the following data into the TDC:

- AoB = 0 -> send
- Speed = 0 -> send
- Distance = max (turn the distance wheel to the right, should give you about 1200yds in the tdc after you send it) -> send

If I may ask a couple of things regarding this portion of your tutorial, Spec.... I seem to be missing something:

1/ You say you are about 700 yds away, but didn't you just infer that you had to be 4600 yards off because the torpedos range was 4600? (Your cue card for Vector says trace backwards from impact point 4600 yds.)

2/ Why do you enter 1200 yds into the TDC... I mean, why enter anything? From 4600 yds, there is no need to enter any distance.

This worked for me the first time! (Although upon trying again, my torps run out of steam as they hit the boat and usually don't explode....unless I move up to about 4500 yards.)

[magic452]

You just draw your course line 4600 yards from the target track.
You do not have to be 4600 yards away, you can be any were along the your course line (500+ yards) and you just shoot at the angle of the constant bearing line.
If your constant bearing angle is say 10° just point your periscope at 10° Left or right of 0° depending on which direction target is coming from and as the ship crosses the wire you fire.

The instructions you refer to are to clear any old data from the TDC so that the torpedo shoots straight out the front. To do this you must set the periscope to 0° and pull the range all the way down to about 1200 yards. Click the send range button twice to set the gyro angle to 0°

To shoot stern tubes you do the same thing only point the periscope to 180° and sent 1200 yd to the PK.

You must also set speed and AoB to 0 for the same reasons.

If you have good accurate speed and course data this is the most acute and versatile shooting method there is, as far as I'm concerned, and Spectator's tutorial is EXCELLENT.

Magic

[DigitalAura]

ahh... I see, as long as the angles all stay the same, the size of the 'triangle' (including range and target path lines) doesn't even matter.
This is cool! I must try this now that I see it's much easier than I thought.

[TwinStackPete379]

Werner, you magnificent bastard, I WATCHED YOUR VIDEOS!!