"Snap Shot" -- to answer your question Johnfb

Bubblehead729 · 01-31-12, 12:05 AM

Quote:

Originally Posted by Alfred Keitzer

But after setting target speed to zero, you MUST turn the TDC back ON so the TDC will follow your periscope look angle -- it will not when the TDC is off -- and you are now using the periscope look angel to lead the target and adjust for the lead angle required.

So after chewing on this for a bit, I want to make sure I'm understanding you correctly...I should leave the periscope trained to 0 degrees relative, and shoot as the target passes the correct relative bearing for torpedo and target speeds. (for example 9 degrees for a medium speed torpedo at a 6 knot target passing right to left). Because if you turn the scope to a different bearing with the TDC engaged, you are altering the gyro angle, and changing your solution.
Have I got that right? Or am I missing it? (the point and the target

)

Alfred Keitzer · 01-31-12, 01:01 PM

Not quite -- you can do it that way, but not required. You don't have to leave the periscope at 0 -- that was just for the demo so you could see the lead (off the nose) computed for different target speeds; and to show you how range has little to no effect on lead angle provided you are shooting within 30-35 degrees of your bow (or stern).

Momentarily turning the TDC off, you have control over the TDC settings. Setting the target speed to zero causes the TDC to compute zero lead angle -- because it thinks the target is not moving. With target speed at zero and turning the TDC back on, the path of your torpedo is now determined purely by where you point the periscope.

So for your example -- target going 6 kts passing right to left using medium-speed torpedo ...

MEDIUM torpedo lead angle = approximately 1.5 x Target Speed = 1.5 x 6 kts = 9 degrees of lead angle.

You've set the TDC OFF; set speed to zero; TDC back ON. Looking through your periscope, you see center target bearing 020 relative. Lead the target with your periscope by 9 degrees -- point your periscope at bearing 011 degrees relative -- and shoot.

Don't forget to open the bow cap (torpedo door) before you shoot. For a target at close range, it can move several degrees in the time it takes to get the bow cap open.

-------------------

To answer your second question -- yes, you are altering the gyro angle with your periscope, which is exactly what you want to do -- you want to alter the gyro angle to lead the target by some number of degrees that you've computed in your head. The only difference between a true TDC solution and the "snap shot" is you are computing the lead based on torpedo speed, your best estimate of target speed, and a rule-of-thumb calculation and using the periscope to apply that lead against the target.

Bubblehead729 · 01-31-12, 01:33 PM

Ahh ok that clears it up. Thanks for the explanation; looking forward to trying this method out.

von Kinderei · 01-31-12, 02:30 PM

Very well explained ...

misha1967 · 02-01-12, 02:30 AM

Thanks, Alfred, for adding that.

Because the "lead" method gives you the additional opportunity to fire off your shots right now as opposed to wait for the target to move into your crosshairs, and that's damn good info for those situation where you have everything else on the money but don't have the time to sit around and wait.

Alfred Keitzer · 02-01-12, 12:48 PM

It all sounds easy in theory, but in the heat of battle, it's easy to forget steps. That's why I try to setup well in advance for the attack. The first thing I do is work to establish a good estimate of target speed. I then look at my torpedo inventory and decide what torpedo speed I am going to use. To keep it simple, I try to use one torpedo speed so I only have to remember one lead computation. I then preset my torpedo speed and depth for all torpedoes. With good Target Speed, Torpedo Speed, and depth set, and having computed my "snap shot" lead ahead of time, I'm now ready for the attack.

Once I determine I am going to "snap shoot", I turn TDC OFF; set Target Speed to zero; and TDC back ON.

I then have a four-step plan for "snap shots". I use this plan religiously because Step #2 (open bow cap) was always the easiest to forget and it will just ruin your day. I use the keyboard so I don't have to keep clicking the mouse between periscope and everything else -- I use the mouse exclusively for periscope work when doing "snap shots".

1. Select ready torpedo {keyboard "Y"}
2. Open bow cap {keyboard "Q"}
3. Find target and note bearing
4. Apply computed lead angle with periscope and shoot {keyboard "Ctrl Enter"}

REPEAT Steps 1. through 4. for each target.

Now as I remember, launching a torpedo in the stock version of SH3 is just the "Enter" key, but I use GWX 3.0 where the command is "Ctrl Enter". Sorry, I don't remember what the command is using NYGM.

01-31-12, 01:33 PM	#3
Bubblehead729 Sailor man Join Date: Nov 2011 Location: In Port Posts: 50 Downloads: 49 Uploads: 0	Ahh ok that clears it up. Thanks for the explanation; looking forward to trying this method out. __________________ There are two types of ships in the world......submarines and targets.

01-31-12, 02:30 PM	#4
von Kinderei Ocean Warrior Join Date: Dec 2007 Location: Virginia Posts: 2,606 Downloads: 150 Uploads: 0	Very well explained ... __________________ vK

02-01-12, 02:30 AM	#5
misha1967 Commander Join Date: May 2004 Location: Texas, USA Posts: 470 Downloads: 78 Uploads: 0	Thanks, Alfred, for adding that. Because the "lead" method gives you the additional opportunity to fire off your shots right now as opposed to wait for the target to move into your crosshairs, and that's damn good info for those situation where you have everything else on the money but don't have the time to sit around and wait. __________________ Ansonsten, Herr Lutter, ist alles in Butter Liqui-cooled Intel i2550K @ 4.2 GHz, 8 Gb RAM, GTX 970 GPU

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01-31-12, 01:01 PM	#2
Alfred Keitzer Kapitän zur See Join Date: Jun 2007 Location: San Diego, CA Posts: 93 Downloads: 264 Uploads: 0	Not quite -- you can do it that way, but not required. You don't have to leave the periscope at 0 -- that was just for the demo so you could see the lead (off the nose) computed for different target speeds; and to show you how range has little to no effect on lead angle provided you are shooting within 30-35 degrees of your bow (or stern). Momentarily turning the TDC off, you have control over the TDC settings. Setting the target speed to zero causes the TDC to compute zero lead angle -- because it thinks the target is not moving. With target speed at zero and turning the TDC back on, the path of your torpedo is now determined purely by where you point the periscope. So for your example -- target going 6 kts passing right to left using medium-speed torpedo ... MEDIUM torpedo lead angle = approximately 1.5 x Target Speed = 1.5 x 6 kts = 9 degrees of lead angle. You've set the TDC OFF; set speed to zero; TDC back ON. Looking through your periscope, you see center target bearing 020 relative. Lead the target with your periscope by 9 degrees -- point your periscope at bearing 011 degrees relative -- and shoot. Don't forget to open the bow cap (torpedo door) before you shoot. For a target at close range, it can move several degrees in the time it takes to get the bow cap open. ------------------- To answer your second question -- yes, you are altering the gyro angle with your periscope, which is exactly what you want to do -- you want to alter the gyro angle to lead the target by some number of degrees that you've computed in your head. The only difference between a true TDC solution and the "snap shot" is you are computing the lead based on torpedo speed, your best estimate of target speed, and a rule-of-thumb calculation and using the periscope to apply that lead against the target. Last edited by Alfred Keitzer; 02-01-12 at 02:53 AM.

02-01-12, 12:48 PM	#6
Alfred Keitzer Kapitän zur See Join Date: Jun 2007 Location: San Diego, CA Posts: 93 Downloads: 264 Uploads: 0	It all sounds easy in theory, but in the heat of battle, it's easy to forget steps. That's why I try to setup well in advance for the attack. The first thing I do is work to establish a good estimate of target speed. I then look at my torpedo inventory and decide what torpedo speed I am going to use. To keep it simple, I try to use one torpedo speed so I only have to remember one lead computation. I then preset my torpedo speed and depth for all torpedoes. With good Target Speed, Torpedo Speed, and depth set, and having computed my "snap shot" lead ahead of time, I'm now ready for the attack. Once I determine I am going to "snap shoot", I turn TDC OFF; set Target Speed to zero; and TDC back ON. I then have a four-step plan for "snap shots". I use this plan religiously because Step #2 (open bow cap) was always the easiest to forget and it will just ruin your day. I use the keyboard so I don't have to keep clicking the mouse between periscope and everything else -- I use the mouse exclusively for periscope work when doing "snap shots". 1. Select ready torpedo {keyboard "Y"} 2. Open bow cap {keyboard "Q"} 3. Find target and note bearing 4. Apply computed lead angle with periscope and shoot {keyboard "Ctrl Enter"} REPEAT Steps 1. through 4. for each target. Now as I remember, launching a torpedo in the stock version of SH3 is just the "Enter" key, but I use GWX 3.0 where the command is "Ctrl Enter". Sorry, I don't remember what the command is using NYGM.