"Cannot compute solution for aft tubes"???

[hunter301]

I lot of times when I am running away from a target I am trying to shoot at him with my aft tubes. Even with the target at a 90 degree angle to me and sitting at a bearing of 180 it keeps saying "Cannot compute solution for aft tubes". I have an aft tube selected.
Why does this happen?

[TorpX]

Make sure your scope/TBT is pointed at 180 deg.

[Sniper297]

Quick tip - if you're using manual targeting go back to auto targeting, you ain't ready for manual yet.

[hunter301]

Make sure your scope/TBT is pointed at 180 deg.


If I'm running away from him then he would be at or around 180 degrees.
That's why I was trying to use my aft tubes. :D

[hunter301]

Quick tip - if you're using manual targeting go back to auto targeting, you ain't ready for manual yet.

Why would this make a difference if I was shooting at point blank range directly behind me.
It was one of those pesky gun boats and it was only a couple of boat lengths away from me.

[Diopos]

Check this:
Link (http://www.subsim.com/radioroom/showthread.php?t=206266&highlight=aft+tunes+solution)

.

[Sniper297]

"Why would this make a difference if I was shooting at point blank range directly behind me."

If you're using manual targeting you have to select the stadimeter and click the "SEND RANGE AND BEARING TO TDC" button every time you point the periscope in a different direction. Also with manual targeting if the target is within 500 yards and it's not heading directly toward you or away from you the gyro angle won't work - a torpedo comes STRAIGHT forward or aft out of the tube, runs in a straight line for 400 yards, then begins to turn to the gyro setting. Try it with autotargeting passing another ship within 500 yards in the opposite direction, then change to external cam to watch the torpedo track. If you're really close it will come straight out of the tube then turn 3/4ths of a circle to hit the target on the side away from you.

Point blank range is no good since (1) torpedo travels 400 yards straight before turning to the intercept course, (2) if the target is on a course and in a direction for a zero gyro angle shot, the torpedo still has to travel 400 yards to arm the warhead - if it hits a target 200 yards away it will be a dud. Minimum range for zero gyro angle should be 500 yards, if the torpedo has to turn more than 20 degrees 1000 yards is better.

[Snarf]

pay attention to your Gyro angle needle, it's the inner set of numbers on the lower dial on your position settings. Watch how it moves when you rotate the periscope. Then look at your aiming point on the attack map and how it correlates. That should give you some insight into how it works and why it's not working for you

[TorpX]

If I'm running away from him then he would be at or around 180 degrees.
That's why I was trying to use my aft tubes. :D Yes, I realize he is at or around 180 deg.

That doesn't mean your scope is pointed at him. Some play the game giving orders from the charts station. You can pop up the scope and see 360 degrees, without bothering to go to the station or turn it to the target.

2 possibilities: 1. the scope was pointed off in left field.

2. previously entered data retained in the TDC messed up it's ability to compute a firing solution.

If it happens again, take time out to look carefully at all the information displayed in the TDC dials. Most likely you will spot something amiss. If you have time, it is advisable to glance at the TDC before you fire, to verify the gyro angle is what it should be.



***

Point blank range is no good since (1) torpedo travels 400 yards straight before turning to the intercept course, (2) if the target is on a course and in a direction for a zero gyro angle shot, the torpedo still has to travel 400 yards to arm the warhead - if it hits a target 200 yards away it will be a dud. Minimum range for zero gyro angle should be 500 yards, if the torpedo has to turn more than 20 degrees 1000 yards is better.

You made me curious, so I looked into the files.

The Mk. 14 has a arming distance of 450 yds. (RFB 2.0 file), though it is reduced to 350 yds. sometime in '43.

The distance the torp travels before starting it's turn (the reach) is about 343 feet, and the turning radius is about 310 feet. I had to determine these experimentally. BTW, the values for the Mk. 10 came out the same.

Doing a little math, I calculate that at a maximum gyro angle shot (135 deg.), the Mk. 14 torpedo will travel about 358 yds. by the time it finishes the turn.

So, the bottom line is, you should not try to torpedo anything closer than 500 yds. Better to keep it to 600 or more, especially, if you are uncertain of the distance.

[Snarf]

Keep in mind too, in real life the arming distance of the torpedo is quite a safety feature. If the torpedo were to hit an ammo ship or even the ammo storage on a warship at a range of 200 yards, it would probably be devastating for the sub too. The other reason is that if you have a circle runner, the torpedo has not travelled 400 yards by the time it comes back to you and does not blow you up. The Mk18's had i think a 200 yard arming distance and a high tendency for circular runs (due to mfg. issues) which caused the demise of the Tang and maybe a couple other subs too.

If you want to reset the gyro angle for a 180* shot point the scope at 180 then hit the lock on target button it will reset your gyro angle to 180 if it doesn't lock onto a ship.