[Pisces]

Originally Posted by J3llyfish

... In a situation as above, I'm supposed to only shoot the 1st deep row of merchants (the ones I underlined)? The furthest ship would cross my 000 gyroangle first, then the second and the nearest last?

No, you do not wait until the target passes the 000 gyro angle. In other words, that would be when he is right in front of you. Instead, you want to turn the scope until the gyro angle reads 0. Then the periscope bearing is something around 350 (in your example above) depending on the target speed and torpedo speed. When the persicope is there you are looking at a point that is slightly further away, but it is negligible. Now you wait until the target passes the periscope line. Because you look to a place before the impact point, the torpedos have just enough lead time to get there while they run straight out of the tube.

And ideally, the torps would hit their targets nearly at the same time. Immediately after that the escorts would be after me.

That is a possibility. Haste is of the essence while the torpedoes are still on their way. Give yourself some time by not shooting at the nearest column ship. Or atleast with some extra distance to give you time. If the target speed is dead accurate then you can hit almost into infinity. (well, if the tubes are open in time)

So the question: is it (in practice) impossible to try to sink any ships from the 2nd or 3rd deep row?

It's possible only if you let the 1st row go, and wait for the 2nd, or 3rd. But with the above way not at the same time.

(i.e. if there were only 3 merchants in that convoy, those that are one after another between the 2 escorts, I could only shoot one of them, because there would be no time to wait for the others to cross my 000 gyroangle since the escorts would be too quickly after me)

If they are indeed in-line behind each other then yes, you would have to swing the scope to point at the other. So this implies the need for a range setting for each individually. Depending on your distance to the target track and the gap between them the difference between the two gyro angles could be substantial. The closer you are the bigger it gets. You'd want the gyro angles to be equally centered around 0 degrees for a (theoretically) simultaneous hit. But that means distinct range settings for each. How much depends on the geometry and speeds involved. You could try to measure it at the time, but targets swing by very quickly in those situations so you 'll never have it exact and on time.

If you know the (halve) gap distance, and your distance to the track then you can figure out mathmatically (with the TAN function) the halve of the angle between targets when they are in front of you. So now the periscope bearings are equally centered around 0 degrees, and you can do with just one range setting that is equal for both targets on either side. However, now the torpedos won't hit at the same time. One is partially head on to the rear target, and the other has to catch up to the front target. Giving the front target time to react to the attack. How much time requires a calculation based on the geometry and speeds involved.

Instead I advise to just keep your focus on one at a time. Certainly as a beginner. It's exciting enough.