TDC Issues

[cwelt]

Alrighty... where to start. I have been sub simming for some time with SH3 and been using manual targetting for some time now but in SH4 I can't hit a barn at 50 meters :P For some reason when I activate the position keeper my target goes from being at bearing 330 (for example) to some bearing way out to lunch. I can spot it through the scope, lock onto it, refeed the data into the TDC but the position keeper throws it all out to lunch!! granted I am not always at a perfect 90 degree angle to the ship I am pursuing or locked onto but I do try to make it as close to 90 as possible but for some reason this darn thing keeps screwing up my solutions. Does anyone have any ideas as to what may be going wrong... I have watched WernerSobe's videos so many times to see if I could spot what I am doing wrong that I can prbably recite them word for word, but as of yet I can't get a solution that will hit a ship to save my life. Grrrr... I love this game to death but I can't sink battleships with my deck gun, they seem to get me first :hmm:

Anyways, if anyone has any thoughts on what I may be doing wrong please oh please let me know...

here's my general walkthrough

1. sonar track's bearing to target
2. raise scope and ID the target, take a reading with the stad meter
3. drop the scope and set torps/open doors
4. raise scope and do second stad meter reading to get speed estimate
5. set AOB to match units course
6. activate position keeper
7. lock scope on target
8. update the range to target
9. check attack map to ensure solution looks good (this is when I notice the ship went from a bearing of about 340 to some wacked out bearing way off to the side of my ship)

I am confused very much... what I am doing should work no??? Sorry to ramble guys, this is buggin me sooo much as I know it should work, but my 12 misses with 12 torp's says I am missing something

[Powerthighs]

When you do step seven, do you lock the scope on the ship before you send the range estimate? Every time you send range the bearing that the scope is pointing at gets sent as well.

[cwelt]

yeah, sorry I forgot to mention that I do a scope lock... let me edit that one

[stufer]

When you get the crew to estimate speed, are you pressing the send to TDC button on the speed section of those dials?

[Rockin Robbins]

Originally Posted by cwelt

here's my general walkthrough

1. sonar track's bearing to target
2. raise scope and ID the target, take a reading with the stad meter
3. drop the scope and set torps/open doors
4. raise scope and do second stad meter reading to get speed estimate
5. set AOB to match units course
6. activate position keeper
7. lock scope on target
8. update the range to target
9. check attack map to ensure solution looks good (this is when I notice the ship went from a bearing of about 340 to some wacked out bearing way off to the side of my ship)

I am confused very much... what I am doing should work no??? Sorry to ramble guys, this is buggin me sooo much as I know it should work, but my 12 misses with 12 torp's says I am missing something

You have several overlapping problems here. Firstly, you are activating the PK way after the data in the TDC is stale. You are developing data in the wrong order. Using the stadimeterto get a speed/course estimate is so innacurate that it should be a last resort option. And you are shooting after you have determined you are wasting a torpedo. Let's fix it.

1. Use radar fixes to calculate speed. Measure the number of yards between 2 fixes three minutes apart. Divide by 100 (drop two zeroes or slide the decimal two places left) to get kph: 700 yards equals seven knots. Enter that into the TDC. Since this parameter doesn't change continuously, you can do this before your turn on the PK.

2. Turn on the PK. All other parameters will continuously update as your own boat and the target move.

3. Set AoB to match unit's course. Now if you change course and speed the target will remain in your crosshairs and course craziness will not occur unless the target changes its course.

4. Lock the periscope to the target. Use the stadimeter and press the send range/bearing button to get the data to the TDC. Your PK is now locked onto the target and if his course and speed remain unchanged AND if your inputs are correct you can shoot any time the target is in range.

5. Switch to the attack map and watch your impact point. It should be superimposed on the target and follow it long enough for a torpedo to travel from its tube to impact point. It is quite easy to see when a change in AoB or target speed is necessary. Just tweak those parameters, repeat step 4, and check again.

6. Don't shoot until your attack map shows the impact point stays on the target long enough for the torpedo to get there. Did you open the torpedo door? If not, open it now, giving plenty of time for the door to fully open.

7. The last thing to do is update the range and bearing just before you shoot.

At any time during the procedure, you can lower and raise the periscope as necessary or desired. Tube opening is not critical so long as the tube is fully opened at time of firing.

[cwelt]

Originally Posted by Rockin Robbins

You have several overlapping problems here. Firstly, you are activating the PK way after the data in the TDC is stale. You are developing data in the wrong order. Using the stadimeterto get a speed/course estimate is so innacurate that it should be a last resort option. And you are shooting after you have determined you are wasting a torpedo. Let's fix it.

1. Use radar fixes to calculate speed. Measure the number of yards between 2 fixes three minutes apart. Divide by 100 (drop two zeroes or slide the decimal two places left) to get kph: 700 yards equals seven knots. Enter that into the TDC. Since this parameter doesn't change continuously, you can do this before your turn on the PK.

2. Turn on the PK. All other parameters will continuously update as your own boat and the target move.

3. Set AoB to match unit's course. Now if you change course and speed the target will remain in your crosshairs and course craziness will not occur unless the target changes its course.

4. Lock the periscope to the target. Use the stadimeter and press the send range/bearing button to get the data to the TDC. Your PK is now locked onto the target and if his course and speed remain unchanged AND if your inputs are correct you can shoot any time the target is in range.

5. Switch to the attack map and watch your impact point. It should be superimposed on the target and follow it long enough for a torpedo to travel from its tube to impact point. It is quite easy to see when a change in AoB or target speed is necessary. Just tweak those parameters, repeat step 4, and check again.

6. Don't shoot until your attack map shows the impact point stays on the target long enough for the torpedo to get there. Did you open the torpedo door? If not, open it now, giving plenty of time for the door to fully open.

7. The last thing to do is update the range and bearing just before you shoot.

At any time during the procedure, you can lower and raise the periscope as necessary or desired. Tube opening is not critical so long as the tube is fully opened at time of firing.

Thanks very much, I figured something I was doing was wrong... your step by step seems alot more fluid than mine did. I will test this out tonight and be sure it is working. I hope you just saved the USN a ton of money in wasted torps

[Rockin Robbins]

Originally Posted by cwelt

I hope you just saved the USN a ton of money in wasted torps

That's the plan. Let me make a plug here for the Dick O'Kane targeting technique, which lets you set up the whole attack up to 30 minutes before you have to shoot. Then you can relax and play some heavy metal on the grammophone until the victim arrives at the shoot point, shoot twice, watch him go down and drink lots of torpedo juice. Success is not guaranteed if you reverse the procedure and drink the torpedo juice first.

It also gets rid of two items that cause lots of trouble for conventional targeters: the stadimeter (booooooo! booooooo!) and the position keeper (hisssssss! boooooo!).

[capt_frank]

I know that by using the attack map, you can tell if you've got a super swell solution by looking at the PK tracker.

But what if you don't have map updates on and you can't see the solution in the attack map, presuming of course that that does that...

Or in real times...how did they know they were spot on? Check, double check, etc. I presume...

****************************************

And yes, the Dick O'kane method is the schnitzel!

[Munchausen]

Originally Posted by capt_frank

Or in real times...how did they know they were spot on? Check, double check, etc. I presume...

In real times, the skipper always had somebody tracking the target on the plotting board. A good skipper (like O'Kane) could tell how an attack was progressing by checking to see when the AoB to the target started "opening up" ... and he would compare his visual checks against the plot and TDC readout.

Unfortunately, in the game, your choice is either: a) to be unrealistically accurate by having an auto-updated attack map; or b) to be unrealistically hampered by not being able to mark your target's "estimated' (via TDC) position on the attack map.

:hmm: If only somebody could figure out how to transpose the compass, ruler, erasure, and pencil from the nav map to the attack map ... now that would be much more realisitic!

[Rockin Robbins]

That is why leaving the map updates on and using TM is MUCH more realistic than turning map updates off, because it simulates the testing of your attack crew to ensure that the solution of the TDC remains good. This testing was a continuous procedure during real attacks and to be deprived of that is MOST UNREALISTIC!

Get TM to get rid of the unrealistic ship silhouettes and velocity vectors and start using your plotting crew like Uncle Sam and Admiral Lockwood intended.

[jazman]

Originally Posted by Munchausen

Unfortunately, in the game, your choice is either: a) to be unrealistically accurate by having an auto-updated attack map; or b) to be unrealistically hampered by not being able to mark your target's "estimated' (via TDC) position on the attack map.

I've finally got TDC and PK figured out, but am using map updates. I was just pondering this issue last night...which is less realistic? I'm going with map updates ON for now, because I see the map updates as representing the work my ace officers are doing. I can't micromanage everything...

I do have the MoBo downloaded, haven't taken the time to figure it out yet.

[cwelt]

Rockin Robbins..... you my friend are a GOD! I went step by step with your suggestions (and althought the range reported both by sonar and using stadmeter were off) the angles and speed of the vessel were correct and I went 4 for 4 with the hits last night. Seems like my next born child will be call XXXXX 'rockin robbins' XXXXXX


Thanks for all your help, you made me (and the USN) very happy

[joegrundman]

Originally Posted by Rockin Robbins

That is why leaving the map updates on and using TM is MUCH more realistic than turning map updates off, because it simulates the testing of your attack crew to ensure that the solution of the TDC remains good. This testing was a continuous procedure during real attacks and to be deprived of that is MOST UNREALISTIC!

Get TM to get rid of the unrealistic ship silhouettes and velocity vectors and start using your plotting crew like Uncle Sam and Admiral Lockwood intended.

I'm not sure I agree here. Even without the tails and silhouettes those map contacts are utterly comprehensive and accurate to within a yard for every unit out there all because you up scope for 5 secs.

Do it twice and you have every course, speed and position with perfect knowledge. This is not even possible today, not unless you are radiating your targets somehow, and that sort of poor Emcon is not normal for modern submarines.

While i accept that the game forces you to choose between two situations, my opinion is that you have no real excuse for missing with map contacts on. Except for duds. Such is the level of accuracy it provides.

Let's assume you are underwater. There is only you looking, or perhaps one other looking through the obs scope if at long range (who ought not to be much more skilled than the skipper), and all the information that goes into being plotted comes from what you say to the 18year old able seaman with the chinagraph pencil. He does not have some some kind of divine knowledge of the outside world.

And this is what a stadimeter plot looked like - Note the large number of observations required to get a good reading and the poor level of accuracy for any given observation:



Now this is a similar plot derived from a periscope fitted with radar. As you can see the accuracy is much greater



These are from the Submarine Torpedo Fire Control Manual 1950

http://www.hnsa.org/doc/attack/index.htm

Now I don't know about you, but when i take stadimeter observations of the target it looks very similar to the first image. When you use the map contact updates on, it looks more like the second image.

The inaccuracies of the stadimeter method are such that the manual states that

"Since the errors in stadimeter ranges may be great and variable the plot is much harder to make and analyze than the periscope radar plot.
A system of fairing in the target's course through the observed points must be used. The plotter must lean heavily on the Approach Officer's angle on the bow in arriving at the proper course line. In general the smaller angles on the bow and the shorter ranges will be the most accurate."

So my point is that the map contact updates on is a far cry from the reality of the situation, and that you need to temper your plots with your own AOB observations.

BTW - to all concerned - I have no problem with people using map contact updates on, or any of the other options available. If that's how you like to play it, then that's great. This is purely a contribution to the discussion as to which options best approximate realism.


joe

[joegrundman]

May i add that I would love it if you could have it such that your own measurement yielded an automatic plot mark on the nav map where you established it to be, but i guess we'll have to wait for the next generation of sub sim for that to happen.

From the same source, the plotting happened on a Dead Reckoning Tracer (DRT) and used apart from chinagraph pencils, rulers and a Parallel Motion Projector (PMP)

From what i read it seems that the PMP served the purpose of the protractor bearing overlay incorporated into TM, but it could also move around holding the same relative bearings, so you could use it in other situations

The DRT was a cool device. It was a glass top table with a pinpoint light "bug" under it. This bug represented your submarine. Magnets could control where on the surface this bug appeared and you could set it so that it would drift along the glass top to match the submarine's course and speed. This of course helps with plotting to target.

The DRT is very much analogous to the way your own ship moves on the attack map screen, but i don't think it could automatically take into account changes in your own course and speed. So it was probably best to stay on the same velocity until your plotting was complete and you were ready to begin the attack phase.

If, as said above, you could make your own marks on the attack map, it would be a great thing as a simulation of the DRT.

joe

[Powerthighs]

I agree, if when you clicked the send range/bearing button, it plotted an X on the attack map, that would give you a plot with all the inherent inaccuracies of actual range measurement.

But of course that doesn't happen.