Quick question about spreads

[ddiplock]

Is the offset angle dial in the US TDC the best way of setting a torpedo spread?

So, you'd set an offset angle of say 4 or 5 degrees to left/right depending on the direction of the target in your scope. So if they are sailing to the right in your scope, you set the angle to the right, and left you set the angle to the left and such.

Just trying to figure out how to get my torpedoes to hit ALONG the target rather than kinda in the same area

[magic452]

You can use the gyro angle offset dial for this but it is so range sensitive that it's difficult. The longer the range the smaller the offset must be. Once you get use to it, it works pretty good. Your example for 4 or 5° would be for very close targets, more like 1 or 2° would be the norm.

If I am using this method I will lock the target and shoot stern to bow -1, 0 and +1° or whatever is needed. At longer ranges 0.5° may be necessary. I do this when I don't want to leave the scope up for a long time.

A better way to shoot a spread is to first take a final range and bearing measurement. Second turn off the PK, unlock the target and move the scope to a positing slightly ahead of the bow and send range/bearing to TDC and then shoot as the ship crosses the wire shooting bow to stern.
The scope is up for a long time so you have to consider the conditions at the time.

Magic

[commandosolo2009]

Originally Posted by ddiplock

Is the offset angle dial in the US TDC the best way of setting a torpedo spread?

So, you'd set an offset angle of say 4 or 5 degrees to left/right depending on the direction of the target in your scope. So if they are sailing to the right in your scope, you set the angle to the right, and left you set the angle to the left and such.

Just trying to figure out how to get my torpedoes to hit ALONG the target rather than kinda in the same area

You my friend, need Dick O'kane's targeting method

Cheers and, for the love of God, keep the spread dial as it is..

[Daniel Prates]

I too am curious about using spread shots, since as many skippers, I am not used to use this.

Isn't there a simple way to more-or-less use the offset dial? I mean, In a simple way to put it: how much angle (number of degrees) should I offset a shot every, say, 1000 meters or so?

[Rockin Robbins]

No, the real submariners used slide rules not available to us. It was easy for them and difficult for us.

[TorpX]

Originally Posted by Daniel Prates

I too am curious about using spread shots, since as many skippers, I am not used to use this.

Isn't there a simple way to more-or-less use the offset dial? I mean, In a simple way to put it: how much angle (number of degrees) should I offset a shot every, say, 1000 meters or so?

Actually, yes there is.
Say you want to torpedo cruiser X at any range and have all the data fed into your TDC and are otherwise ready to loose death and destruction, but for the spread matter. Observe the angular distance of the target; if the stern is at 350 deg., and the bow at 354 deg., you know the target occupies 4 deg. of arc. So you can shoot your torps -2, -1, 0, +1, +2 for 100% coverage. You could also shoot -1.5, 0, +1.5 for 75% coverage. You get the idea. Notice that the spread is in both directions, not just ahead or behind. This is not a perfect method as it doesn't take into account the reach, turning radius of the torpedos or whether the range is closing or opening, but is a good quick and dirty method.

How much coverage should you use? That depends. The main reason for shooting spreads is to make up for errors in the firing solution. If you are confident in you solution you can get by with little or at least less than 100%. If the solution is shaky (as is often the case), more than 100% is indicated.

Frequently, I am not using the TDC and use a longitudinal spread. This is just a different means to the same end though.

[Rockin Robbins]

That's fine but the tick marks on your periscope are different angular sizes for different screen resolutions. Once you know what they are for your computer, you can do this. On the real periscope, different sets of eyes did not change the angular size of the ticks.

[Daniel Prates]

Thanks TorpX!

[TorpX]

Originally Posted by Rockin Robbins

That's fine but the tick marks on your periscope are different angular sizes for different screen resolutions. Once you know what they are for your computer, you can do this. On the real periscope, different sets of eyes did not change the angular size of the ticks.

I'm not talking about the tick marks. I mean turning the periscope/TBT and using the index ring with the center wire. That should be good for any resolution (at least I hope so).