(ask) problem with enemy's course and precisely fire torpedo with sonar

[lajulanian]

I had a problem with enemy's course and precisely fire torpedo with sonar.

step that I already done :
1. I enter the sonar room, find the bearing until the light is on.
2. send bearing to the TDC.
3. determine the target. if enemy, in below 4000 m, it point to the some range.
4. I send the range to the TDC.
5. Fist : I set mark 1 to the enemy's ship.

and I repeat the sep 1 -5. until I get fifth mark. but the result on the mark is get me confuse.to set the angle of bow (AOB)

is there any suggstion ?

Nb: I use sonar because is Night. dark...

Thanks... sory for the bad english

[DrBeast]

Check out , should give you plenty of insight into how to do a sonar attack. If it doesn't load, is also very useful.

[Daniel Prates]

Full-sonar firing is, anyway, a secondary form of targeting and is usually less precise than visual methods... note that you mention precision, but sonar-oriented measurements always have a large margin of error. Can't you really peak for just a few seconds to add a stadimeter reading or two? That will increase your accuraty greatly.

[lajulanian]

Originally Posted by Daniel Prates

Full-sonar firing is, anyway, a secondary form of targeting and is usually less precise than visual methods... note that you mention precision, but sonar-oriented measurements always have a large margin of error. Can't you really peak for just a few seconds to add a stadimeter reading or two? That will increase your accuraty greatly.

take a peak ?? ok.. good advice.

thanks a lot..

[Rockin Robbins]

I'm making another video of the Dick O'Kane Sonar Only technique some time soon. I borrowed a microphone last night and it sounded like a 1940's AM radio: not acceptable. Really there is nothing at all to be gained with a stadimeter reading. Sonar gives much more accurate (capitalize that. It's many times better.) range information than the stadimeter.

Where you might actually want to take a peak is right when you fire to get a perfect shoot bearing. On bearings, the periscope is more accurate than sonar.

So: your most accurate instrument for range is sonar or radar.

Your most accurate instrument for bearing is radar or periscope.

[Daniel Prates]

Originally Posted by Rockin Robbins

Really there is nothing at all to be gained with a stadimeter reading. Sonar gives much more accurate (capitalize that. It's many times better.) range information than the stadimeter.

RR, that is understood, but you mean active sonar. By reading the fellow's procedure in the first post, I understood - incorrectly? - that he uses some sort of multi-reference calculation with passive sonar. I guess that if he was using multi-pinging, he would not have the problems mentioned.

There are also other things to consider, such as revealing your own position. I never - that of course is just my playing stile - use active sonar.

You must have some sort of visual, anyway, even if it just to identify the target. Wouldn't want a large liner on your conscience, would you?

That could be an interesting discussion. How frequent you captains actually use active sonar, and in which occasions?

[Rockin Robbins]

Originally Posted by Daniel Prates

You must have some sort of visual, anyway, even if it just to identify the target. Wouldn't want a large liner on your conscience, would you?

That could be an interesting discussion. How frequent you captains actually use active sonar, and in which occasions?

Uh.... I was in the middle of the Japanese Ocean, detected a great swarm or warships on sonar, did three pings to track a large noisy target, fired three, hit with three and sank......the USS Essex.

That was the end of my longest career. Assuming the target has been identified, the scorecard looks like this. You've just pinged the target:

They--O Crap!!! Somebody just pinged us. There's an enemy out there somewhere.

Us--Target! Bearing 054! Range 3150 yards!

Now you tell me if you gain an advantage by pinging.

As a submariner you spend a lot of your time in fear for your life. Isn't it great to make the enemy fear for his?

[MKalafatas]

I nearly always use sonar without periscope or range info, once I've ID'd the target. Range is irrelevant if you fire from the beam (limited only by torpedo arming distance and max torpedo range). Ergo, I use only passive sonar. You need only know the target speed, course, and correct firing angle. (e.g., 7 knots translates to an 11-degree firing angle if you're perfectly on the beam, and use a 36-knot Mark X; 9 knots = 14-degree firing angle). When the sonar man calls out the bearing of the approaching target, and it reaches the firing angle, I shoot. Actually I generally shoot about 1 or 2 degrees in advance, depending on how large the target is and how many torpedo hits will destroy it.

If you wait the 8 seconds or so for the "torpedo in the water" call, that generally translates into about 2.5 or 3 degrees of target bearing, moving across your bow.

Using the stadimeter, my torpedo accuracy was around 50 percent. Using sonar only, it exceeds 75 percent.

One caveat: zig-zagging targets are very difficult to hit this way.

Edit: so it was YOU who sunk the Essex?????

[Char]

Originally Posted by Rockin Robbins

I borrowed a microphone last night and it sounded like a 1940's AM radio:not acceptable

What do you mean not acceptable? as least it would sound Period Correct!

[Daniel Prates]

Originally Posted by Rockin Robbins

They--O Crap!!! Somebody just pinged us. There's an enemy out there somewhere.

Us--Target! Bearing 054! Range 3150 yards!

Now you tell me if you gain an advantage by pinging.

Yeah, again, this is a playing-style subject, but in this scenario, the next line for them could be "left full rudder, all ahead flank", and your torp would probably be a miss. Visual ID and ranging has the advantage of being able to lurk silently up until a torpedo impact.

We discussed this last year, but I dont remember the outcome: if you are in a ship, say, a freighter, can you hear a sub pinging you?

[MKalafatas]

RockinRobbins, thanks much for the link to the O'Kane method YouTube vids. I didn't know about the two clicks issue on the TDC.

[Rockin Robbins]

Originally Posted by Daniel Prates

Yeah, again, this is a playing-style subject, but in this scenario, the next line for them could be "left full rudder, all ahead flank", and your torp would probably be a miss. Visual ID and ranging has the advantage of being able to lurk silently up until a torpedo impact.

We discussed this last year, but I dont remember the outcome: if you are in a ship, say, a freighter, can you hear a sub pinging you?

That's just it, the merchies had no listening gear at all. The warships, rather than turning to avoid, if anything, would turn to engage. But they can't tell the bearing from which the ping is coming.

Their logical reaction would be no apparent reaction at all as their sonar guys feverishly try to hear the sub and get some kind of bearing. THEN they would turn toward, but they would have done that anyway upon deciding that they had a solid sonar contact on a sub by passive sonar. They would turn toward and go active.

Since their reaction to a ping is the same as their reaction without a ping, the only difference is that you've definitely told them you're out there.

Therefore pinging (with warships) should be done with a lot of thought if you believe they don't even know you exist. At that point you have such a huge advantage you may wish to keep it that way and listen passively. Good periscope technique is also probably going to keep you totally unknown.

Pinging warships is a slam dunk when they already know you're out there and you're looking for an edge. You've told them what they already know and you've learned their exact location.

But with merchants it doesn't matter. They don't know you're pinging. That's historically accurate too.

[TorpX]

Originally Posted by MKalafatas

I nearly always use sonar without periscope or range info, once I've ID'd the target. Range is irrelevant if you fire from the beam (limited only by torpedo arming distance and max torpedo range). Ergo, I use only passive sonar. You need only know the target speed, course, and correct firing angle. ....

At the risk of coming off as onery, I feel I have to point out a few things here.

The "range is irrelevant" is often repeated, but is really misunderstood. It is true that you can compute the lead angle for a firing solution, knowing the speed, track angle and bearing, without knowing the range, but that does not mean the range is irrelevant. (Also, it has nothing to do with the sub being on the "beam". The range dropping out of the equation for the lead angle holds only for a zero-gyro angle solution, whatever the positions of target and sub.) The firing solution for a 4,000 yd. shot may have the same angles and speeds, as a solution for a 2,000 yd. shot, but they are not the same. A small error in the data that would get you hits at 2,000 yds., would likely produce misses at 4,000 yds.

The thing often glossed over is the question of how would you obtain the speed or course without knowing the range? Speed might be estimated by observing the bow wave or by 'seaman's eye', but this would require visual observation anyway. Timing by wire also requires visual observation. The only other way I can think of that would not require any range info, is to use propeller counts. I think in practice RL captains relied mainly on calculations of distance/time (i.e. plotting). Another thing is that it would be almost impossible to determine the target's course without either knowing the range at several points, or accurately observing the AoB. This brings you back to visual (or radar) observations again.

Only a very few "sonar-only" attacks were made by US submarines. As far as I know, none were successful.

[Daniel Prates]

Originally Posted by Rockin Robbins

But with merchants it doesn't matter. They don't know you're pinging. That's historically accurate too.

That's the info I was looking for!

I know they dit not have "active intercept" tech, but lets especulate on this a little bit. When we (subs) are submerged, we can hear pings clearly. There is NO WAY a merchant crewmen could hear a ping as well? I'm not talking game-wise anymore, just exchanging ideas.

The sound travels best in water, sure, but the reason we hear a ping when submerged is that the sub is very silent, and we are surrounded all around by water. It would be my guess that, in a noisy ship, and with surface noices (wind, waves etc) interacting with all other sounds, the ping would have to be pretty damn strong for you to hear it...

[Daniel Prates]

Originally Posted by TorpX

At the risk of coming off as onery, I feel I have to point out a few things here.

The "range is irrelevant" is often repeated, but is really misunderstood. It is true that you can compute the lead angle for a firing solution, knowing the speed, track angle and bearing, without knowing the range, but that does not mean the range is irrelevant. (Also, it has nothing to do with the sub being on the "beam". The range dropping out of the equation for the lead angle holds only for a zero-gyro angle solution, whatever the positions of target and sub.) The firing solution for a 4,000 yd. shot may have the same angles and speeds, as a solution for a 2,000 yd. shot, but they are not the same. A small error in the data that would get you hits at 2,000 yds., would likely produce misses at 4,000 yds.

The thing often glossed over is the question of how would you obtain the speed or course without knowing the range? Speed might be estimated by observing the bow wave or by 'seaman's eye', but this would require visual observation anyway. Timing by wire also requires visual observation. The only other way I can think of that would not require any range info, is to use propeller counts. I think in practice RL captains relied mainly on calculations of distance/time (i.e. plotting). Another thing is that it would be almost impossible to determine the target's course without either knowing the range at several points, or accurately observing the AoB. This brings you back to visual (or radar) observations again.

Only a very few "sonar-only" attacks were made by US submarines. As far as I know, none were successful.

Ha! My point exactely.

Another key issue to consider is that you should always try to fire from as close as possible. All margins of error decrese as you near in (except for your personal safety margins, but that is another issue). If we are talking about a lonely merchant, it is fairly easy to lurk ahead of him and wait till he is less then 2000, maybr 1500 meters away. And in that situation, a couple of statimeter readings are all you need for a "good-enough" range (and speed!) estimate.