TDC Range and it effects?

[Phoenix3000]

Hi guys,

I always use full manual targeting and manual TDC (no officer assistance) when plotting through to eventually firing the torps.

Thing is, after having read a lot about how range can affect the gyroangle ever so slightly I have a question about attacking convoys:

OK, for example sake I've set up a 90 degree angle of attack. The convoy is, say, 6 columns deep by 4 rows (24 ships). The distance to the first column would be 600m at 90 degrees. The second 1.2km, the 3rd 2km etc.

Now, if firing a spread to hit the lead ships what would you set the torp range at?

Setting it at 600m will certainly hit the first column, but that would mean the next torp would possibly go behind the ships in the second and 3rd column etc.?

Now, short of changing range (very quickly on the TDC) before firing each torp, what do you guys do - set them all for long range (the furthest target), or leave them short? What is 'best practice' so to speak?

I would just like to get an idea of what others use.

Thanks all,

Px3000

Forgot to add - playing SH3 1.4b - GW1.1a - SH3 Commander - SH3Gen, and soon to try SH3 Weather (when back in port).

[Sawdust]

I don't think that a spread of torpedoes will work in this situation; instead, a series of individual launchings would be better.

Not too long ago, there was a thread started by a guy who had perfected the art of the convoy attack. It is definitely worth a look:
http://www.subsim.com/radioroom/showthread.php?t=99767

[fredbass]

Setting it at 600m will certainly hit the first column, but that would mean the next torp would possibly go behind the ships in the second and 3rd column etc.?

Torpedoes can run as far as they are capable of, no matter what range you set, I do believe.

[Albrecht Von Hesse]

Something you have to understand about the range. Range isn't a matter of how far the torpedo is set to travel. Range is one leg of a triangle used to compute the torpedo settings.

The only time range isn't a factor is a dead, bow-on or stern-on shot, with your angle of attack about zero degrees as well.

As an example (and the numbers are fictional, I haven't actually trigged them out) let us look at the following: say there is a ship traveling 10 knots, perpendicular to your heading (in other words, picture it moving from 9 o'clock to 3 o'clock, with you at 6 o'clock and pointing at 12). At a range of 1,000 meters the torpedo has a gyro angle of 10 degrees at time of launch (remember the numbers are hypothetical). At a range of 2,000 meters it would need an angle of 20 degrees. That's because the path it travels will be twice as long at 2,000 meters as it is at 1,000 meters.

If you're trying to target ships in a convoy in different columns you definitely will have to compute the ranges to each one. For that matter, you need to do so even if they are in the same column.

Easiest method I've come up with for manual targeting multiple ships is to first determine speed as closely and as accurately as I possibly can. Until it hits the fan, what one ship's speed is in a convoy they all will be. Then I select which ones I'll be targeting, and preset my torpedoes speeds, depths and pistols for them. I'll track the 'deepest' one first (i.e. the one furthest away in the convoy) and compute its range then fire, then shift to target #2 next. That way, hopefully, all my torpedoes wind up on target about the same time, so there's little to no time for my subsequent targets to begin evasive manuevers.

[von Zelda]

The most important factor is accurate target speed followed by an accurate Angle on the Bow (AOB). I don't believe target distance is used by the Target Data Computer to determine the offset angle of the torpedo from dead center of aiming point. However, torpedo speed (slow, medium or fast) would affect the offset angle of firing and the distance of torpedo travel before giving out.

This is all a function of geometry. Given a set target speed, AOB and torpedo speed for any sub to tartget distance the offset angle of the torpedo track would be the same I do believe.

However, accurate sub to target distance will affect the notebook's computation of target speed if you use this method to determine target speed. If you do not use this method for computing target speed, I don't think accuracy of the distance is too important.

For example, if you were to use the Weapons Officer assistance to compute torpedo firing angle, you would notice that it gives you the immediate sub to target distance, not the sub to torpedo intercept point which you are looking for.

All that being said, compute the convoy speed and AOB (because all merchant ships in the convoy will have the same speed and AOB). Estimate the distance to the furthest target. Aim periscope/UZO and shoot at the farthest target and then at the closer target.

Then you best "RUNN OFT" before the destroyers and frigates come for ya.