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-   -   Need help shooting two targets at the same time. (https://www.subsim.com/radioroom/showthread.php?t=219434)

james_nix 04-04-15 05:23 PM

Need help shooting two targets at the same time.
 
Ok, I see a convoy and I have a perfect 90 degree angle.

One ship is at 350 and the other at 10. With four torpedoes, how do I shoot both?

The only thing that worked for me was to input the info in the TDC for the first one, fire, then lock on too the second one, click range, speed, AOB on the TDC all over again. It seems like that is a lot of work and precious time if the info is exactly the same.

I tried shooting the first one, then locking onto the second one and firing, but that didn't work. Then I tried shooting one, then shooting again with 20 degrees to the left for the torpedoes. That didn't work either.

The position keeper is off the entire time.

Is the only way to do it is to click the TDC all over again for the second target, even if the info is the same?

Crannogman 04-04-15 06:38 PM

Presumably you are using manual targetting, correct?

james_nix 04-04-15 08:38 PM

Quote:

Originally Posted by Crannogman (Post 2303812)
Presumably you are using manual targetting, correct?

Yes

Sniper297 04-04-15 09:50 PM

"then lock on too the second one, click range, speed, AOB on the TDC all over again. It seems like that is a lot of work and precious time if the info is exactly the same."

The range, speed, and AOB should be close enough that all you should need to do is lock the second target and click the "Send range and bearing to TDC" button. You can also use the "seaman's eye" (AKA Kentucky Windage) to compensate, set the crosshairs just ahead of or just behind the target and click the "Send range and bearing to TDC" button. Main thing is (1) make sure the outer doors are open before starting the attack, if you let the automatic gadget open the outer doors for you it does NOT update the gyro angles to compensate for the firing delay so it's a guaranteed miss. (2) fire a spread, either by using the gyro angle offset or (better) shifting the scope a few degrees and clicking the "Send range and bearing to TDC" button again between each shot. And (3) when you think you're close enough get closer - you'll get a lot more hits at 500-1000 yard range than you will at 3000 yards because the target has less time to see the wakes and maneuver to avoid the fish.

Crannogman 04-04-15 10:29 PM

How far out can the AI spot a torpedo wake?

Sniper297 04-05-15 11:07 AM

Depends on the sea state and visibility. At night when the water is choppy and the wind is kicking up spray and whitecaps they might never see the wake at all, but in clear weather daylight with calm seas they can see the wakes from as far as 4000 yards. A Mark 14 set for high speed goes about 1500 yards per minute, so if you shoot from 1000 yards the target has about 40 seconds to detect and react. 500 yards gives him 20 seconds, time enough to say "EEEK!" but not much else. 2000 yards gives him one minute and 20 seconds, which is often enough. Attacking at night in choppy seas I have gotten a good percentage of hits with overlapping targets from 8000 yards with the fish set for low speed, but anything over 2500 yards in the daytime you need a lot of luck to actually hit anything except anchored ships.

When you think you're close enough, get closer. :arrgh!:

merc4ulfate 04-05-15 07:44 PM

It is easy. With all doors open fire at the first then move the scope ten degrees towards the next one and fire at it too..

Sniper297 04-05-15 08:53 PM

That's with auto targeting, with manual targeting you need to click the "Send range and bearing to TDC" button each time you move the scope, if you don't the gyros will send the next fish toward the previous target instead of the current one. That's the way it was done in real life too - range, bearing, AOB, target speed all entered, TDC tracking, "Final bearing and shoot, up scope!" Center crosshairs, click button, fire one, fire two, "shift targets!" - aim crosshairs at second target, forget speed range and AOB, just click the button to send the all important new bearing to TDC and fire away.

merc4ulfate 04-06-15 01:57 PM

Leave the scope where it is and turn your rudder fire at ten degrees offset.

Sniper297 04-06-15 07:04 PM

I think we're starting to see the flaw in self education. :know:

That would work, but shifting the scope 10 degrees and clicking the button is faster.

merc4ulfate 04-06-15 08:04 PM

Come on you have never done that?

I took three ships out without touching anything but the rudder. Manual set up. Scope set to zero. Most likely 1000 yards or less from the targets. All I did was turn the boat and fired 6 fish into three targets sinking all three.

You lose about 5 seconds for speed run up so you just lead the target. It is the same on radar or sonar bearing shots. You know that receiver has to go around so you never shoot at the target because it will always lead your line of fire. You can't sit at the sonar and at the scope so you learn to lead the target.

I took out the Yamato in a typhoon with an average yardage of about 1000-1500 using radar alone. You do not need math when you know how the devices your using work.

It is like using the Israeli instinctive shooting method. You just know where it is going.

Sniper297 04-06-15 10:55 PM

Yeah, I'm familiar with "Kentucky Windage", my oldest son was a US Army artilleryman (motto, Ready, Fire, AIM!). IIRC it was Edward L Beach himself who used the "angle-off" method, guesstimate the speed, set range at 1000, speed and AOB in the TDC to zero so you have a zero gyro angle, then fire when the target hits the crosshairs 10 to 15 degrees left or right (depending on estimated speed and crossing direction). Instead of firing a spread, fire all tubes on the same bearing but spaced out 10-15 seconds apart, the motion of the target takes care of the spread all by itself.

I still find it much faster to shift scope, click send button, and fire than to turn the whole sub.

TorpX 04-07-15 12:38 AM

For those who like approximate methods, you can try the SPEED PLUS 3 method.

Does it work? I don't know, but it was used in RL by at least one S-boat crew. (Don't ask me which one.)

Fish40 04-07-15 05:51 AM

This video may help: https://www.youtube.com/watch?v=AnOsBxVi84U

Sniper297 04-07-15 06:46 PM

Good video. :salute:

I keep forgetting to mention, one type of mod that's a must have (unless you're already running a mod that includes it) is one of the ship acceleration physics mods. In the stock game a freighter chugging along at six knots sees a wake, lights the afterburners and peals out like a hot rod on a drag strip.

It's especially aggravating if you're playing an Asiatic campaign because you're bound to run across those floating fiascos that have half a dozen tiny troopships escorted by a bunch of crazy destroyers and 3 cruisers. They start out in a perfect formation and a few miles later the cans are zipping in and out of the columns causing the troopships to scatter hither and yon, and at each waypoint they seem unable to figure out which way the next one is and mill about at 1 knot in various directions then suddenly speeding up to go in circles at 20+ knots for a while, then stopping or slowing to 1 knot again. It's like trying to shoot torpedoes at a cluster of waterbugs even with the physics acceleration mod, without it you're just wasting time and torpedoes.

SSI01 04-09-15 05:14 AM

I'm afraid I cheat and use the auto-TDC method - math never was my strong point. What has seemed to work for me is to whenever possible never shoot more than 1000 yds away from target. As previously stated, this should give the captain on the target ship just enough time to spot the wake at the last second and give a call over the 1MC for everybody to jump up off the deck plates at the same time to keep from having their ankles broken - then make a fast break for the boat deck.

What takes rather complex figuring is trying to time the torpedo impacts for two separate targets at different ranges to occur within 5 or 10 seconds of each other. This keeps one target from applying evasive tactics after seeing their buddy get hammered.

Can someone give us the speed in fps for a Mk 14 and Mk 18 torpedo, Mk 14 speed setting "high"?

Sniper297 04-09-15 01:27 PM

When you think you're close enough, get closer! :salute: Shoot within 500 yards and they have enough time to see the wake and go "EEEK!" but not much else. :arrgh!:

As for speed, Mark 14 on high does 46 knots. Nautical mile is 6080 feet, 46 x 6080 = 279,680 feet per hour. Divide by 3, 93,267 yards per hour. Divide by 60, 1554 yards per minute. Round it off to 1500 yards in a minute, general thumb rule figure 20 seconds for each 500 yards. 1000 yards in 40 seconds, 1500 yards = 1 minute, 2000 yards = 1 minute 20 seconds, 2500 yards = 1 minute 40 seconds, 3000 yards = 2 minutes. Rounding off means the impact times are off by a few seconds, but if you're shooting at one target 2000 yards away and another 1000 yards away, wait 40 seconds between shots and both should impact within a few seconds.

EDIT: Missed the Mark 18 part of the question - speed is 29 knots, using the same math I did for the 14 see if you can calculate it.

SquareCanine 04-09-15 04:24 PM

The torpedo map will give you the time to impact for whatever shot you have ready (that may depend on map contacts being on?).

The best I've done recently was 4 torpedoes on two targets (Sargo). I open up all the tubes I am going to use and set speed, detonator, and depth (gyro seems to be constant, not tied to the tube like other settings). Plan out the gyro I am going to use for each shot ahead of time, and wait for the lead ship to be about dead ahead for an easy AOB calculation.

Fire at the rear target first with slow torpedoes, then the lead ship with fast ones. From around 1.3km out, the timing was within around 10 seconds (which is a little less time than I spent setting up the second shot).

I can't think of a way I'd rather do it. It's a little tense if subsequent shots need to be made quickly, but it's also really rewarding when it all comes together nicely.

SSI01 04-09-15 05:10 PM

Thanks Sniper 297! Excellent info.

I use a variation of that rule re: Mk 18s v. Mk 14s. As recommended, the 18s are launched against the targets farther away on the theory they are supposedly wakeless and, since they will be in transit longer, this will cut down on the likelihood they will be spotted en route. The second half of the double- or triple-whammy consists of the Mk 14s that are fired at the closer target(s). The trick when doing this is to carefully watch the angle on the bow for each target; if you are shooting at more than two ships you're almost certain to have to "twist ship" between the first and second shots, or the second and third. It will cut down on the available time to settle on your course before firing the last torpedo(es). Attention to detail is critical.

Aktungbby 04-09-15 06:33 PM

welcome aboard!
 
SquareCanine!:Kaleun_Salute:


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