A valid use of high school geometry!

[ronbrewer]

I'm sure a lot of U-boat skippers out there already know this or have their own systems for closing in on a target with a perpendicular course, but this was a frustrating problem for me early on after going through Wazoo's excellent tutorial on manual targeting. What I found was after getting the target's course/speed and getting way ahead on an end around, once I made the 90 degree turn to get on a perpendicular course I had to halfway guess or eyeball how far to come in before cutting the engines and going to periscope depth. Usually as the target got close I had to back up or go forward to adjust at the last moment.

What I found out after going back over some right angle stuff, that was taught in high school (early 80's for me), is that the cosine of 60 degrees is 0.5 and means that whatever the range is at that moment in the periscope will be the double of the range at 0 degrees. I tested this to make sure the game follows this principle and it's been working out great for all my recent shots. I had a Small Merchant show a range of 1300 meters when the periscope was at 60 degrees (I was on its port side, 300 degrees if I were starboard) and so I went ahead and entered 650 meters for the range and let the torp fly at 0 degrees. I ended up with a shot right at the middle of the ship. Now, coupling this with Wazoo's instructions on getting the AoB ahead of time makes for a less rushed last few minutes of the hunt. This has helped out a lot in rough seas where the waves cause you to lose your lock and you constantly have to keep relocking the target. With the speed, AoB, and range preset, you only have to wait for the gyro to reach zero.

[Der Schatten]

That's great info, I will try it tonight........oh, wait.....I think I vowed to never use anything I learned in school....or more correctly, "why do I have to learn this junk, I'll never use it!"
Of course in my day, we didnt have geometry.....angles werent invented yet....my math went something like: "If one wooly mammoth is traveling west at 2 miles and hour, and the glacier is retreating at 1 inch a day, how long before man discovers flint". :hmm:

[Wolfram]

Originally Posted by Der Schatten

....Of course in my day, we didnt have geometry.....angles werent invented yet....my math went something like: "If one wooly mammoth is traveling west at 2 miles and hour, and the glacier is retreating at 1 inch a day, how long before man discovers flint". :hmm:

:rotfl: :rotfl: :rotfl:

[Rosencrantz]

And if you would like to find out the range to the track, you can use this, it's enogh precise:

Range to the track = Ab/60 x R,
where "R" is range to the target sighted.

[Onkel Neal]

Ya know, high school teachers should use SH3 as a teaching aid. Would sure get me interested

[clive bradbury]

Nealmeister, aren't you rather too big for high school? (I am too polite to say 'too old').

[vois2]

That's an elegant insight by forum user ronbrewer, and a unique perspective on using the 30-60-90 degree right triangle for the attack run. I'm a high school math teacher, and have been thinking for some time about incorporating SH3 into classroom discovery. There are a number of fun applications in the game for students who have mastered angle work and are approaching/have learned simple trig. Good work, ronb!

[Sawdust]

Originally Posted by vois2

That's an elegant insight by forum user ronbrewer

Yeah. I've been using the map drawing tools to measure the expected range when the ship reaches 0° bearing, but this 60° rule is a handy little shortcut.

[Col7777]

Now I use a completely different method.

The conversation goes something like this:

1st Officer - “A ship has been spotted about 7000 yards off the port bow sir.�
Me- “OK number 1, I’ll work out a target solution.�
1st Officer thinks to himself, ‘Oh no not again.’
Me - “Right number1, we left port on Wednesday or was it Thursday, well no matter. What day is it today?�
1st Officer - “Sunday sir.�
Me - “Right so we multiply Wednesday by Sunday and divide by the position of the sun, where is the sun number 1?�
1st Officer - “Over there sir.�
Me - “Right OK, so we multiply Wednesday by Sunday and divide by over there, so where is this ship number 1?�
1st Officer - “On port side about 7000 yards and closing sir.�
Me - “How fast is it going?�
1st Officer - “Not sure sir, I’m no good at that sort of thing.�
Me - Neither am I number 1,well never mind, open the bow tubes and get ready to fire.�
1st Officer - “Sorry sir but that would be a waste of time because we have not more torpedoes left at the front end.�
Me- Well OK open the stern tubes then, we are going to sink this one, I can feel it in my water number 1.�
1st Officer - “We are pointing in the wrong direction to get any where near sir, we will need to turn I think.�
Me - Nonsense number 1, I’ve made all the calculations, get ready to fire.�
1st Officer - (sigh) “OK sir ready when you are, but I do think we need to turn a little first.�
Me - “Just get ready number 1, I know what I’m doing.�
1st Officer - “Ready sir.�
Me - “Fire one!�
1st Officer - “We can’t fire one sir, it has already been fired.�
Me - “Well fire two then.�
1st Officer - “That’s been fired too sir, we only have one torpedo left sir.�
Me - “Well I was right then fire one.�
1st Officer - (sigh) “Yes sir, five fired… eh, I mean one sir.�
Stopwatch ticks away…
Soundman - “Torpedo sounds detected sir.�
Me - “Course they are, I just fired one you stupid boy.�
Soundman - “But sir the sound is getting closer.�
BOOM!
Later floating on the water…
Me - “Well we did hit something number 1.�
1st Officer – “Yes sir, even if it was ourselves, good shooting sir.�
Me – “Do you think I should have divided instead of multiplying or visa –versa?�

[Nopileo]

Originally Posted by Der Schatten

Of course in my day, we didnt have geometry.....angles werent invented yet....my math went something like: "If one wooly mammoth is traveling west at 2 miles and hour, and the glacier is retreating at 1 inch a day, how long before man discovers flint". :hmm:

:rotfl: :rotfl: :rotfl:

Argh.. (wiping my tears and closing the door to my office to avoid stares from passing colleagues)... That is the funniest thing I've read in a long time... :rotfl:

Anyway, that tip from ronbrewer was excellent! I feel I'm getting closer and closer to disabling the weapons officer help completely...

Edit: Just read Col7777's post now, which makes it even harder for me to keep my face here... :rotfl:

[Duli]

LOL@Col7777. :rotfl:

[SmokinTep]

:rotfl: :rotfl:

[don1reed]

:rotfl:

...also,

Range x sin(AOB) = Distance to track

[Der Schatten]

I have a friend who has this game, one of those crazy 100%'ers....(more or less....he does like to look at the carnage he inflicts by using the external camera)........I was sitting behind him, marveling at the math he was doing.......lining up a shot with an accoustic torp on a flower corvette.........all went well, he fired, then dove to duck under the convoy....we were watching the convoy regrouping, and keeping an eye on the corvette......not noticing that the corvette that was headed north was now headed south, with the torp dutifuly following along behind it........the corvette made a sharp turn, the torpedo right behind it and ploughed right into a T2....that was then that we discovered he was right under the very same T2 that got hit.......kind of like shooting an arrow and running and catching the same arrow.......it wasnt pretty, but his math was excellent!

[Farside]

yea its a fine art i've still to master, lol (manual targetting)


i find that for accoutic torps unless your a right numpty (no offense) you cant really miss (very easily) :P :P