speed of torpedo?

[Pawian]

Hi

I play silent hunter 3, patch 1.4.

I elaborated complicated system of torpedoing. Distance from u-boot to enemy ship, and angle between him and our uboot.

Then I use trigonometry to count distance, where enemy ship will be when our perisopce is 0.

Now i need tip how i can choose torpedo speed, so i can fire it at the appropriate time.

I dont ask about TDC and - slow medium or fast, but mannualy choosing torpedo speed for example 20 kilometers per hour or 30.

Help pls.

[Mittelwaechter]

Welcome aboard, Kaleun Pawian.

The torpedo speed settings are fixed.
The electric eels are limited to 30 Kts (or better 28Kts unmodded - its a bug)
The steamers are fixed to 30/40/44 Kts iirc. There were no other speed variations available with the German U-Boote until later in war. Homing torpedos had different (fixed) speeds and some rare long range versions (Dackel) were going realy slow (not simulated in SH3).

You can change the settings to other fixed speeds via modding - but then again you should have only this given sheme of one speed setting for electric and three speedsettings for steamers.

There is no ingame choice other than given/modded set.

[Pawian]

hmmm, so whichc mod i need to choose torpedo speed??

I want speed value that I want, no only 3 of them...

[Mittelwaechter]

There is no way to have more than the given speed settings. You can only change the fixed speed settings to some other fixed speed setting.

You won't have any ingame flexibility to set any speed variation but the given ones.

skwas Silent 3ditor is the modding tool - you'll find it here aboard.
A forum search for 'torpedo speed modding' or similar will show the files to be altered.

As far as I know there is no existing mod available with altered speed settings. You will have to mod them by yourself.

Edit: Your complicated trigonometric approach would be fine, if there were more variable speed settings for the torpeodes. But there aren't.
Do your math with fixed torpedo speed and variable angle of attack. ;) That's what they did (or the TDC).

[Pawian]

if there is no possibility to change torpedo speed, whole method is useless....

[Mittelwaechter]

Let's see...

There are three G7a torpedos available - the original one, the FAT and the LUT.
This may enable nine speed settings (3x3) - via modding. Not sure if doable.
Additionally there are four G7e torpedos - TII/TIII/FAT/LUT.
Another four speed settings (maybe more if they can be converted to 'G7a types' - via modding. If so there would be 12 more speed settings).
We have two (or 3?) Homing torpedos. If it is possible to deactivate the acoustic warhead, you'll have two/three - or if convertable to G7a types six/nine - additional speed sets.

At best you could have 30 different speed settings. But you could have only six loaded into your tubes and some 20+ into a type IX (I don't know the capacity of a type IX - never played it in the last ten years). The XXI may have even more loadout?

You would have to make all torpedos available in your timeframe. This has been done.

[Mittelwaechter]

if there is no possibility to change torpedo speed, whole method is useless....

True. :yep:

[Pawian]

I even dont know what u talking about. I am newbie in sh3, and even dont know how to reload torpedos.

If there is no posibillity to choose torpedo speed, how i can torpedo correctly with mathematic method??

Dont say me anything about kinds of torpedo beacuse i dont understand.

btw. u be from Poland?

[Mittelwaechter]

There are some clever and well written tutorials on how to sink ships with different grades of 'realism'. There are even Youtube clips showing how to do it.

There are some mods providing more and better tools to do the job.

I myself did a tutorial on sinking ships with hydrophone data only.

Great fun to learn all the stuff - and you are the right guy to do it. Never heared of a newbie working on trigonometric target solutions. :up:


Im your western neighbour. We built the iron coffins you're sailing in.

[Pawian]

During WW2 they count torpedo way with mathemathic, I want the same.

Where i can find mod that let me choose speed of torpedo??

[Aktungbby]

Pawian!:Kaleun_Salute:

[Mittelwaechter]

Yeah, they did 'count torpedo way with matemathic'. But the torpedo speed was given.

There is no mod available to give you torpedo speed by choice. It is unrealistic and would have to be made extra as a fun mod.

Goto Google: 'tutorial sh3 torpedo' and watch some Youtube.

This may be of help: http://www.subsim.com/radioroom/showthread.php?t=96026

[Pawian]

Hmmmmm, Hmmmm
http://i57.tinypic.com/2qvwo7d.jpg

I have got idea.....are there torpedos that explode after choosen time?

[Mittelwaechter]

Torpedos don't explode after chosen time but on impact, or by magnetic fuse passing a ships keel or premature due to earths magnetic field fooling the magnetic fuse.

[Sailor Steve]

Hi, Pawian, and welcome aboard! :sunny:

What Mittelwaechter is trying to explain is that even in real life the torpedoes had three settings, and no more. They could not tell the torpedo what speed to run at, except for those three.
http://www.uboat.net/technical/torpedoes.htm

All calculations had to be based around that fact.

[Pawian]

So what to do, if I want torpedo with mathemathic method?

[Mittelwaechter]

The TDC helps you with your target solution.

You have to find the distance to target, as the angle on bow (AOB) and the speed of the target.
This data is/was necessary to make the TDC calculate the correct turning angle for the eel after leaving the tube.

If you want to shoot straight and hit the target perpendicular, you have to position yourself correctly and translate the speed of your torpedo into range and accordingly the speed of the target into its range/traveling distance to meet the torpedo and the ship at the impact point.

You have to calculate the bearing showing in your periscope matching the position of the target in relation to the position of your U-Boot/your torpedo in relation to the speed of both objects.

Assuming the ship moves at 10 Kts and your torpedo runs at 30 Kts.
The ship moves 300 meters while your torpedo moves 900 meters.
What is the correct angle in your periscope to release the torpedo?

:)

[Pawian]

Hmmmm, but first i need to know from which angle i am looking

Hmmm, it is not stupid what u said. I should count it reverse to mathemtaic trygonometry??

I have distances and from it i have to designate angle?

[BigWalleye]

So what to do, if I want torpedo with mathemathic method?

What you should do is what was actually done historically. The calculation included a fixed speed which was preset for the torpedo. (Some had three speed settings, others only one speed.) Based on this torpedo speed, the target speed, torpedo reach, torpedo turning radius, and torpedo track angle at impact, you calculate the torpedo gyro angle setting, which is programmed into the torpedo, and a lead angle, which is the bearing of the target from the submarine when the torpedo must be fired. Then wait for the target to reach this bearing and fire. That is how it was actually done. The TDC (TVR) in SH3 will do most of the calculation for you. You have to enter the target speed, target angle on the bow, and range, and the TDC will do the rest. (Especially the German TVR, which will calculate the lead angle for you!)

The Submarine Torpedo Fire Control Manual http://www.hnsa.org/doc/attack/index.htm is the actual training manual used by the US Navy. It describes in detail all the calculations, as well as attack tactics. Same physical situation applied in U-boats. The KM's Submarine Commander's Handbook can also be found here http://www.maritime.org/doc/uboat/index.htm. It's lees mathematical than the US version, but does describe KM tactical doctrine in detail..

[Pawian]

I start understanding and thinking how to count this angle.

But how i can check distance to enemy ship???

[Mittelwaechter]

If you shoot perpendicular this greek guy Pythagoras says distance is irrelevant.

For all other scenarios you may want to use the stadimeter in your periscope (for now, as a newbie).

Watch this: https://www.youtube.com/watch?v=87ga-Jmef7k

[BigWalleye]

I start understanding and thinking how to count this angle.

But how i can check distance to enemy ship???

Several ways:

1. Some versions of SH3 use a stadimeter (split image device) to measure the range.

2. Hitman's Optics and Hitman's GUI use the angle measurement reticle built into the scopes.

3. You can get a range estimate from your Weps Officer or hydrophone operator.

4. You can use the "God's-eye view" on the nav map.

Method 2 is historically accurate. 3 and 4 were used, but the game version is just too good and never makes a mistake. And real U-boat periscopes didn't have a stadimeter.

[sublynx]

The fifth way is using maneuvering board techniques:

https://archive.org/details/maneuveringboard00unit

[Mittelwaechter]

Let's keep it simple, my dotcomrades.

He's on vanilla 1.4 and just startet to play.
Let him do the basics and then he will find all the other sophisticated stuff out of interest.

[Pisces]

If there is no posibillity to choose torpedo speed, how i can torpedo correctly with mathematic method??The basic lead angle intercept formula:

torpedo speed*sin(lead angle)= target speed*sin( AOB)

In math this relationship is based on the law of sines (Wiki) (http://en.wikipedia.org/wiki/Law_of_sines).

Consider your targeting triangle in terms of speeds and angles only. Not distances! That is only important to predict the time of the impact. If the speeds and angles of the triangle are correctly determined, then the impact is virtually guaranteed. (ignoring the target trying to avoid the torpedo)

The TDC already works this formula out, based on target speed dial, torpedo speed setting and AOB dial. (if you didn't know, on the F6 page) It then adds this to the current periscope bearing and tells the torpedo to turn to there. But a further correction is added to account for the forward position of the tubes and the straight section and turn of the torpedo track when launched. But it's effect is minimal unless at really close range with large gyro angles (large torpedo turn from the bow).

You want to know the distance and the bearing to help with plotting. And know when not to shoot because the target is too close. Plotting helps to determine the target speed. But there are also other ways to determine that. So, for aiming, distance by itself isn't the driving factor.

If you shoot perpendicular this greek guy Pythagoras says distance is irrelevant.No, not because of perpendicularity. It is because the targeting geometry can be reduced to a triangle of a specific shape (doesn't have to contain a right angle), but arbitrary size. So it doesn't matter how far away the target is. If the target is further away, it is also further away from it's point of doom by the same proportion, and the torpedo has to travel a longer distance to that also by the same proportion. The shape of the triangle won't change if you make every side bigger by the same ratio.
The torpedo can impact the target hull at any angle. It's just that perpendicular hits allow for the best margin of error on the target speed.