Shooting torpedoes >= 4000m suggestions
 

Hello,

I play this game since the beginning and I have tried to kill with torpedoes far beyond 4000 m in the early war 1939-1941+-.Im bored with kills at short range. I use Rub 1.43.
My tactic for far targets (+ no change for dd to get you):
1) I calculate the speed+bearings of the target after passive sonar. I draw a line of the the targets course (hydrophone, several times placing ruler lines)
2) I place myself before the target on a 45 degree position so the distance to the target should be constant and if everything is ideal the target does not change his speed
3) I place a marker on the map after the sonar guy says bearing 000 (Often I cannot see the target)
4) I calculate the range to the target expl : 4000m
5) I calculate the time the torpedo would need to 4000m : fast speed T I torpedo 44 knots : 44 knots = 22.635555536 m/s. (1 knot : 0.514444444 m/s )4000m / 22.635555536 m/s / 60 = 2.945218 minutes = +- 180 seconds.
6) after the 3 minute rule I calculated the speed of the target: expl : 10 knots
7) I calculate the distance the target would move on his traject : 0.514444444 * 10 = 5.144 * 180 : 925 m
8) I draw a line of +- 925m on the course : this is the spot my torpedo will have to hit the object.
9) I draw a line from the 925 m mark to my sub icon and check the degrees
10) I put data in the TDC : fast T I, in this case 15 degrees to the right and shoot the torpedo


Ok, this may look stupid for mathematicians ( I am not a mathematician as you probably have noticed), I have many remarks. I think this looks good on paper but I have many problems with this method to kill beyond 4000 m.
1)My torpedo always deviates from the angle I put in the TDC, the error will probably become bigger after time + when i shoot I am not 45 degrees from the target so the torpedo also has to change his course after launching (this will probably make an inaccurate course of the torpedo).
2) It is not handy for killing convoys because of the problem with the passive sonar, I cannot let the sonar guy track the ship I want to track,It is always the nearest target
3) The ruler cannot measure distances accurately, this causes my calculations to be inaccurate
4) when I shoot the torpedo the distance the torpedo has to follow is always larger because the angle I shoot the torpedo is not 0 degree. For example : the distance becomes 4100 m instead of 4000m
5) completely ineffective when there is bad weather
Can someone make it more effective,

thanks for reading

I use the Fast 90 method for shooting. There are a variety of ways to determine a target's course so you can arrive at a perpendicular course, but I don't go into that. I just cheap and use the AoB from the WO and calculate the target's course using a formula.

Once that's done, I fired a torpedo under a target at nearly 10k using a TI on slow setting. I forgot to switch back to magnetic, so it passed right under the ship. Very disappointing after waiting nearly ten minutes for a hit.

Of course, at that distance, having a good range estimate is probably more important for scoring a hit. I just recycled the dated range the WO gave me and plugged that in. Not sure if you can even get an accurate distance using the mast height at 10k.

Anyway, it can definitely be done without auto TDC. But it's easiest if you're nearly perfectly perpendicular to a unaware target in calm seas.

Re: Shooting torpedoes >= 4000m suggestions
 

Your distance/ time math appears correct to me ( 925m would be covered in 3 min at 10kts). However are you taking your angle on the bow from where the target is currently or where it will be at impact time? Im pretty sure it should be what the angle is at launch time. Other than that I would say to get consistant hits at 4000+m you will need to fire spreads instead of single shots.

Do you mean the 3:00 Rule or the 3:15 Rule? I find 3:15 minutes:seconds to be more accurate. On the other hand, I loathe long-range attacks, and I still prefer to get as close as possible.

and also, you need to calcul and do a "open tubes" launch ....

Indeed Knotical
Im manually calculating the steps that the TDC makes in about 1 second after input,

I miss the AOB, I only took my own angle to the boat.

yesterday I tried it at 8000m and scored a beam shot with one shot after exact the seconds I calculated (without a red line on the chrono) :sunny:. Although the limitations of the ruler makes it quite annoying. Is there a possibilty to mod the ruler into greater detail? (+ I cannot let the sonar guy track the ship I want to track,It is always the nearest target : can this be modded? Or is there a way to track the ship that is not the nearest target with the hydrophone that is locked in the periscope/UZO, I do not know how to do it)
@stratege : I always do a 'open tube' command :)

...just a note:

3 min rule is for distance in yards.
3:15 min rule is for distance in meters.

also, if you have the speed and AOB precise, then the actual distance doesn't matter. A "hit" will take place at 500m or 5000m if you have the target's speed and AOB down solid. Coveat: Make sure you're cross-hair is MOT.

Offset Angle of Collision = asin ( (target speed/torpedo speed) x sin AOB)

I don't believe that Set caused by ocean current is modelled.