How to manually input range?

[jazman]

That's another annoying thing with that stadimeter. I mean, why would anyone want to set a range arbitrarily on empty ocean air?

[Rockin Robbins]

Originally Posted by jazman

That's another annoying thing with that stadimeter. I mean, why would anyone want to set a range arbitrarily on empty ocean air?

Setting the range lets you see a projected torpedo on the attack map screen. It really doesn't matter what the range is, although I usually set for about 1000 yards. With the Dick O'Kane attack method you set your torpedo bearing a long time before you ever see a ship. You check that by looking on the attack screen and seeing if the torpedo is going to head out in the correct direction.

Let's say the target is making 7 knots and is approaching from the left. We're at right angles to the track. We'll set up the speed on the TDC for 7 knots. Then we'll set the periscope at the bearing where we want to shoot, in this case the lead angle will be just under 10º, so we'll set up our aiming angle to 350º. Aim the perisocope to that bearing. Then go to the TDC and manually set a range (1000 yards seems like a fine number!). Press the send range/bearing button. Now you can check the attack screen and see the torpedo track going out at about 358º. That's what we want, a right angle track to the target, which is the most error tolerant track. We're ready to shoot and haven't seen the ship yet except on radar!

Now all we have to do is get a decent distance from the track and point the periscope at 350º. When the juicy parts of the ship go by the crosshairs, press the trigger. That spot on the boat is exactly where the torpedoes will hit.

See the whole seminar complete with screenshots at http://www.subsim.com/radioroom/show...6&postcount=67.

So, why would you ever want to set range manually at a spot in the empty ocean? To sink the enemy!

[jdkbph]

I'm not sure, but I think we're missing the point of the question.

I think he's asking (and if not, I am... this is something I have wanted to do on several occasions but haven't been able to figure out) how to set the range to some specific number without using the stadimeter - which requires that the target be in sight and locked.

Why would you want to do this? For me the main applicaiton would be when using RADAR on a dark night and/or in heavy fog. I can see the target on the screen, use the map to approximate the distance accurately enough, and take various marks over time to get speed and heading. I can then manually input the target speed, bearing and AoB, but with no way to input the range I can't generate a firing solution.

I should be able to do this, no?

JD

[THE_MASK]

Its in the manual , page 35

[Fincuan]

Yes you should be able to do it, but since SH4 doesn't directly allow it, you have to use the stadimeter, the sonar or turn the range wheel manually(goes up to 4000 meters with metric system btw).

edit: Page 35 is about the stadimeter, which doesn't help in this case. Page 36 tells you how to calculate the range manually, but still the above three ways are the only ones to actually input the range to the TDC.

[klh]

Originally Posted by jdkbph

I'm not sure, but I think we're missing the point of the question.

I think he's asking (and if not, I am... this is something I have wanted to do on several occasions but haven't been able to figure out) how to set the range to some specific number without using the stadimeter - which requires that the target be in sight and locked.JD

Yes JD, that is exactly my question. I can do this in SH3, but not in SH4. Thanks for saying it clearly. Maybe some clever modder can fix this (or perhaps it will surprise us in 1.4).

Its in the manual , page 35

My manual shows ship IDs for two gunboats and a sampan on page 35. Maybe you've got a better manual with your version. That's OK, because my manual is a good coaster to keep my desk clean of coffee rings.

[Fincuan]

Originally Posted by klh

Yes JD, that is exactly my question. I can do this in SH3, but not in SH4. Thanks for saying it clearly. Maybe some clever modder can fix this (or perhaps it will surprise us in 1.4).

ok, once more: In Sh3 you have direct control over the tdc inputs, and thus can set the values to anything you like by simply turning the wheels. You can't do that in SH4. In SH4 you have direct control over only aob and speed. Range can only be set via on of these methods: Stadimeter, turning the range wheel manually(only values between ~200 and 4000 meters) and sonar. That's it, and there's currently no way to set the range via a simple wheel like could be done in SH3.

[Rockin Robbins]

Actually being limited to under 1300 yards for manual setting on imperial measurements is no problem. If you're shooting from outside 1300 yards with conventional targeting methods you're too far away (I like to be under 800 yards). If you're using the Dick O'Kane technique you don't care what the range is anyway because it isn't a targeting parameter.

Part of effective shooting is extreme error tolerance, especially in a convoy that is scattering. You have to assume that your setup isn't right and be close enough so that whatever error you have is within the allowable tolerance. I've taken shots from 500 yards because I knew my setup was lousy. BOOM! anyway.

[klh]

Originally Posted by Rockin Robbins

Actually being limited to under 1300 yards for manual setting on imperial measurements is no problem. If you're shooting from outside 1300 yards with conventional targeting methods you're too far away (I like to be under 800 yards).

RR, you are correct that the ability to set long ranges on the TDC is not an issue for firing (I would rarely waste a fish at more than 1000 yards). However, that is not what I'm trying to do, so this limitation is a problem for me and I think it's unrealistic that we're unable to directly enter a target range into the TDC (like I can in SH1, SH2, and SH3).

I am wanting to use the position keeper to track the target from long range. Say for example, I could put in a range of 8000 yards plus the AOB and speed. I could enter that data into the TDC and turn on the PK. Then I could go deep and quiet until the escorts have passed, and know when the best time would be to return to periscope depth to finalize my solution before firing.

Anyway, thanks to all of you for your comments. You answered my question -

Originally Posted by Fincuan

ok, once more: In SH3 you have direct control over the tdc inputs, and thus can set the values to anything you like by simply turning the wheels. You can't do that in SH4.

That's what I figured, but I was hoping I had overlooked something.

[jazman]

Originally Posted by Rockin Robbins

Setting the range lets you see a projected torpedo on the attack map screen. It really doesn't matter what the range is, although I usually set for about 1000 yards.

I was being sarcastic, sorry I didn't make that clear, but the comments following were still interesting. Now I need to figure out (that is, really understand) why this is true. Because without pondering it, it seems counterintuitive.

Now, I've been using the O'Kane method. So in my best attacks I've pointed the ship at the target's track, and I've set the periscope at 0 degrees. I enter a range (with any requisite fiddling needed) to the target's projected track in front of me (along the 0-degree path). I enter the AOB at that point, too, which has been about 90-degrees (port or starboard). I enter the speed. It seems to have worked so far, so if I increase the range it seems that my gyro angle would end up being larger, to make up the extra distance?

In other words, it seems that I need to get the range right. At least for the way I'm doing it. I get a couple of checks on the target's path to ensure my range will be good. Am I doing the O'Kane method, or am I doing some Jazman method? I shoot fish as the juicy parts of the ship cross the periscope crosshairs.

A nice variation would seem to be to run parallel to the ship, and point the periscope at 90-degrees (or 270, depending on direction) so I can bring rear fish to bear, good for convoy attacking. Is this right?

[jazman]

Originally Posted by jazman

I was being sarcastic, sorry I didn't make that clear, but the comments following were still interesting. Now I need to figure out (that is, really understand) why this is true. Because without pondering it, it seems counterintuitive.

Rockin Robbins has explained this to me quite satisfactorily. It has to be a right triangle in the targeting solution. When I work out the equation to figure out a gyro angle, I notice that it has nothing to do with range, but only the speed of the target, the speed of the torpedo, and the gyro angle, and the time to travel (which cancels out).

( X seconds ) x ( TorpSpeed yds/sec ) x ( sin(GyroAngle) ) = ( X seconds ) x ( ShipSpeed yds/sec)

Where X is the time to travel to hit. Range doesn't appear in the equation! (A diagram would help.)

sin(GyroAngle) = TorpSpeed / ShipSpeed

And with my calculator, it's easy to find GyroAngle.

So from my misses on my missions, I may not have been mis-estimating the range, but the angle on bow. (and / or the speed.) I was being a bit sloppy with the AOB, just eyeballing it.

For a non-right triangle, I can see the range is in there, and can't get cancelled out. (I'm looking at the laws of sines and cosines, is that right?) I see why I need a TDC to figure out the Gyro angle for me...