Issue with the O'Kane method. Also: savegames

Hey guys, I hope you can help me with this.

Everytime I try out a 90° attack, every torpedo passes in front of the target. This happened at least 5 times now and I have no idea what I'm doing wrong.
I take the speed and course, set myself up in a nice 90° angle, calculate the lead angle and put the data into the TDC. Exactly like DepthToKeel does in .
(at about 9min)

Everything works out fine for him but for some reason my torpedoes are always to early at the planned impact point by about one ship lenght.
I've double checked everything: target speed, the TDC data (impact at 90°, gyro at 0°/360°), and so on, however I don't hit the target.

My second question is about savegames. Last time I tried this method I saved before I took the shot. After loading, the time was different and the target was nowhere to be found. Is this a common bug?

Modlist:

1_TriggerMaru_Overhaul_2-5
1_TMO_25_small_patch
RSRDC_TMO_V502
RSRDC_V5xx_Patch1
1.5_Optical Targeting Correction 031312 for RSRDCv502
1.5_OTC_Realistic Scopes for 16 to 9 RSRDCv502
Improved Stock Environment_v3_TMO&RFB

[propbeanie]

Rockin Robbins will be a better diagnoser of your 'failure to impact' issue, but have you watched his video on it, found in the Sub Skipper's Bag of Tricks thread?



As for your mods, is the Improved Stock Environments a later or earlier date than the patches? How about Realistic Scopes? And, of course, OTC. Just be sure you have them installed in the correct order, and that they're all compatible with each other. Also, corrupted saves are unfortunately a companion to all versions of SH. Several factors are at play there, and all aren't known... Another thing to check for on saving - don't get impatient with it like I've been before, and use TC to hurry things along, such as getting below the thermal, and forgetting to turn TC off while you go through the "Save" process, 'cause a lot of time can pass when you do that...

Edit: Just got to looking at RR's video, and I'm wondering if you're hitting the set buttons twice. Watch the dials as RR hits the buttons a 2nd time, and that might well be the difference. Notice at 9:25-40 especially...

I've made double sure that the mods are all of the correct version and compatible.
I'm also pressing the TDC buttons twice and as I said, the values are correct.
In his video RockinRobins isn't even that precise with his measurements but still hits the target without much issue.

Here's what I do:
1. Take the speed and course of the target. (Place one mark at the target and another one after 3min, the distance between the two points / 100 is his speed, i.e. 1000yards = 10kn)
2. I set myself up at a 90° angle to the target course at about 1000-1500yards.
3. I calculate the lead angle by drawing two lines in a right angle (one for his speed - 1000y and one for the torpedo speed - 3100y) and measuring the angle (or simply using this site). In this example it's 18°.
4. I set my periscope at 0° - lead angle (or + if target comes from the right)
5. In the TDC I set the speed, max out the range and set the AOB to 90° - (or +) lead angle. For the last two I make sure to click the send button two times.
6. The TDC now shows me an impact angle of 90° and a gyro angle of 360° straight ahead. I double check with my attack map and everything seems to be fine.
7. Still looking exactly at the lead angle, i wait till my target crosses the line and fire one torpedo at the first mast, the second at the stack.
8. I follow my torpedoes through the scope and see both passing peacefully infront of his bow...

So, as far as I can tell, steps 1-7 are exactly what DepthToKeel is doing and his torpedoes are going exactly where he aimed them.
First I thought my speed calculation is off, so I double checked that by taking another measurement. Nope, still 10kn.
Then I thought, maybe I messed up and installed the wrong OTC version (and that screws with where I see the target and where he really is / giving me a wrong angle or something), but thats also not the case.

Maybe I'm blind and miss some obvious mistake here but idk.

[Captain Dave]

I usually don't use torpedo speed in my calculation. If the ship is traveling at 9 knots or slower, I set my periscope to +/- 10* of my angle to the ship. If 10 knots or faster, then 15* lead. The AOB is set to angle of ship to my sub.

So, if ship is 90* to sub, periscope is set to 0 +/- 10*. AOB is set to 90*.

[Barkerov]

Originally Posted by dergrunty

5. In the TDC I set the speed

Thats the error you are making. If you leave the speed set to zero in the TDC you will hit the target.
The reason for this is that you are determining the lead andle for a ten knot target, when you set the speed in the TDC, it thinks its job is to calculate the lead angle as well. This is why you are always firing in front of the target.

Try the vector analysis method once you get sick of always having to set up 90 degree attacks. That method extends the dick okane method to non 90 degree scenarios. I use it now because it does the same thing as the okane method plus more.

be sure to post your next exploding target for us

[Gray Lensman]

Unrelated to your shoot issues:

To get the benefit of actually playing the TMO mod. Remove the RSRDC mod.

Why?

The RSRDC overlay actually changes TMO major game realism behavior beyond just the historical ship movements. You are NOT playing TMO when you load up RSRDC following it. You are playing a morphed version of RSRDC that has been touched up (so it doesn't crash when loading after TMO) to make you think you are playing TMO with only the historical ship movements changed.

Also, avoid saving during ship encounters AND definitely DO NOT save on top of another save. In other words do not do SAVE overwrites. I always do fresh saves and then go back into the Save menu and delete old unneeded saves. Note, you cannot delete saves from the Load menu screen.

[Gray Lensman]

Originally Posted by Barkerov

Thats the error you are making. If you leave the speed set to zero in the TDC you will hit the target.
The reason for this is that you are determining the lead andle for a ten knot target, when you set the speed in the TDC, it thinks its job is to calculate the lead angle as well. This is why you are always firing in front of the target.

Not necessarily... see below...

Try the vector analysis method once you get sick of always having to set up 90 degree attacks. That method extends the dick okane method to non 90 degree scenarios. I use it now because it does the same thing as the okane method plus more.

be sure to post your next exploding target for us

I always set the speed to target speed and achieve well over 95% hits (including duds that hit but don't explode), BUT...

you have to ensure that the target will indeed be at or slightly outside the predetermined TDC range setting (especially at higher target speeds). The reason for this is at such close range and higher target speeds the TDC lead angle will cause a bow shot (wire on front (bow) portion of target ship) to actually cross in front of the target instead of intercepting the bow. This intercept range is adjusted preferably by a small judicious forward/reverse ship movement, but can be done on the TDC, (necessitating double-click rechecking of the solution of course).

In a way this somewhat agrees with your reasoning about target speed setting but allows the TDC to still compensate for other small targeting errors such as the sub not being exactly 90 degrees perpendicular to target track

Another point... I never use SLOW speed torpedoes UNLESS i'm setting up a dual target solution and in reality I don't think that was really a historical technique anyhow. At least, I've never read of it being used in any of the books I've read.