Remarkable work here. Much to study. And ys the US skippers did indeed use the tools they were given in very creative ways...and got results too. thanks for these excellent postings and all the info for a shellback to study.

Ckalk up another one with the DO method:up: I recieved a radar contact at 10nm, bearing 75 degrees. I turned towards the contact and reduced speed. I took a bearing and estimated range and made my first plot. Started the stopwatch for 3 min. took second bearing and estimated range. I determined that the target course was NW.

I plotted a course 90 degrees to the target track, and prepared the torpedoes and TDC. Monitoring the radar screen, the range began to close until the "ship spotted" alert rang out. Training the TBT at the announced bearing, I saw the outline of a ship in the darkness. He's getting close now.

I swung my bow around just ahead of him, and timed him as he crossed the 0 bearing line of my TBT. It took him 21 seconds. At this point I fear he may see me, so I go to PD. I up the Obs. Scope (useing the color filters mod; I use the yellow one. ) and ID him as a Medium Modern Comp. Freighter. I have a list that I hand wrote of all the ship lengths. Useing the simple formula to find speed, I determined him to be going 10k.

At this point everything is set: TDC, torpedo speed and depth, target speed and AOB. Nothing left to do but open the outer doors and wait for the ship to cross my scope. Two Mk 14's speed off and impact 30 seconds later:rock: About a half hour after that, down he went. I'm truely beginning to love this targeting method:yep:

The input crank is one of the eight at the bottom of the TDC. The crank can be used to set the bearing in the same way that a winder on a clock can set the time forward or backwards. When the TDC is running and the bearing of the target is being advanced by the computer, the operator will manually crank the bearing crank in the opposite direction, keeping the bearing on the TDC contant.

An analogy would be trying to keep a clock at a fixed time, whilst it is running, by winding the spindle that allows you to set the time backwards. This is one of the 'skilled' parts of being a TDC operator. Anyone who has ever used a lathe or milling machine will know the skill and dexterity you need to feed in at a contant rate so as to give a uniform finish.

The difference between using the crank to keep the bearing matching the aim point and turining the PK off, is that everything is updated. As your ship and the target ship are still closing each other down, or possibly moving apart, if you are in a bad position, the problem is changing. With the TDC running and the bearing being held everything, e.g. the range, AoB, torpedo run length, gyro angle order etcetera are updated with the new problem.

I take it you are running with map contacts off? You could try using my radar range mod, it's in metres, so you'd have to convert it, but it is quite accurate for manual plotting.

Right, just had a quick check of the functional diagram for the TDC to check my facts. There is a very subtle, but very important difference between the real TDC and the in game TDC.

The real TDC has the bearing input crank connected via an adder to the target course (relative tagret course is what the TDC refers to it as, but it's the same as AoB). The in game TDC does not. What this means is that when you adjust the bearing, the target course (AoB) also alters to match. We know from the other explanations about how to get the AoB by drawing it on the map, that the AoB is the angle between the target track and the bearing to your sub. If you can imagine the target moving up and down the target track (like its on a rail) then as the bearing changes, so does the AoB by the exact same amount.

For example, if a target is deads ahead of you at a bearing of 000, steaming a course relative to you of 090, then when the target was at a bearing of 315, the AoB was 45 and when the target will be at a bearing of 045, the AoB will be 135. So that's the maths behind it, the relationship between the AoB and the bearing is a simple addition/subtraction.

The target course is also connected to the range counter by an integrator, so changes in the target's range and course, due to its own movement are taken into account.

What does this mean? It means that with a real TDC, when you hold the bearing you are keeping the course the same and this means that the solution you have is always valid for the point where your scope's aiming wire intersects with the target's course (regardless of where the target is. The target's speed is fed into the gyro angle solver, so the torpedoes will be sent on their way to intersect with the target as long as your speed estimate is correct. You are effectively making the TDC simulate a constant bearing reducing range problem for the aiming point. You are basically on a collision course for your aiming point and the target moves accross the aiming point.

This is all quite confusing and is hard to visualise without a diagram, but the basic principle is that the stern has a different relative course than the bow, when seperately viewed. In game, as the TDC does not change the AoB with a change of bearing, then winding the bearing back will not work accurately, as you'll get a different course. This should only generate a small error however. It's easier to try to visualise this if you imagine an infinitely long target.

Sorry if none of this made any sense.

my two cents
 

After a lesson from RR, I came accross a merchant in the Mallacca Straight near Singapore. I overran it in pitch darkness, and had to chase it through the night after it spotted my boat, in order to salavage a firing position. I finally was able to set up for an eyeballed broadside at around a thousand yards. The merchant was cloisng from my starboard--its port, at 22 degrees, so things were moving right along. When it hit 10 degrees in the crosshairs, I started unloading torpedoes-six of them- in the rapid sequence, firing as follows: 1. at the bow, 2. at the aft mast, 3. at the command tower, 4. at a point about half way betweein the command tower and the stern mast, 5. at the stern mast, and 6. at the stern. I set the range on the stadimeter before letting them loose, as instructed. Six for six, with torpedoes iimpacting in sequence from aft to sterm. There was such noise caused by the the impacts that my three toy poodles went racing through front doggy door in a state of hysteria, intending to find and sink their chops into the trespasser who foolishly dared invade their space and make such a racket. I closed the door behind them, and watched contentedly as my prey slid under the waves. My crew voted unanamously that I should quit while I am on top. I doesn't get better than this.

Nisgeis, that was a GREAT explanation why the real TDC was better than the game TDC at constant bearing shots. In short, with the ability to crank the bearing input backwards (there are clutches inside the TDC that allow this to happen so everything isn't "hard wired" together with gears. Think about it, you couldn't crank in the bearing to begin with if that weren't true:rotfl:) they had a real-time AoB update with the change in TDC bearing similar to that modeled for the U-Boat TDC in SH3 and 4.

The real submarine had no need to be at 90º or 45º to the track. We only do it in the game because it allows us to use simple rules of thumb to input the AoB. Dick O'Kane the person didn't have to do that.

For SH5 I think they need to ship a new computer peripheral: a little USB crank that you can use to make inputs into the TDC, and which coincidentally, you could use to crank backwards to perform the REAL Dick O'Kane maneuver.

Now, to change the subject, I'm goin' down, by the power vested in me by WernerSobe, Nisgeis, aaronblood, gutted, and the infinite might of man's imagination, I hereby dub you Knight, First Class, of the Dick O'Kane Manual Targeting Technique. May you use it well and wisely, always for the forces of right, good and and niceness. and never for the agents of evil and rottenness.

now that I have been knighted
 

Knight is great. I wll ride a sea horse into battle. But right now, I am listening to sonar only tutorials and then I will return to decipher Nisgeis' masterful explanations.

Is SUBSIM a great place or what?:up:

fun?
 

Trying to install Jammimadrid's mini chron and tools got my machine out of whack and I was up until 5:30 a.m. reloading the game, mods, etc. I have given up on the tools aspect and ancient 46 is reviewing my mods and the mini chron, so I may get them in sync this year. Meanwhile, my WEBSTER'sS deck gun, which I downloaded as part of package of his mods for 1.5, takes between 17 and 18 seconds to reload. rahter than 2 seconds as he indicates. I confirmed it on my FULL SIZE stop watch. And, my source of relief, the CaptainsGirls, GirlsInEveryPort, and Captain'sDeskPhotos mods do not show anyone, yet alone, women. Oh yea, that and a destroyer that has a sonar man who never sleeps, and is on my ass, makes this sim something, but I am not sure what.

I saw your mod Nisgeis, and it looks like it would definitely be useful. I do keep the map contacts off for a more realistic experience. I was wondering if your mod is compatable with the latest RFB:hmm:If is is, I'll be downloading pronto!:yep:

map contents off?
 

With map contents off, I do not have to worry abouit speed because I never find anything. How do you find a target?, besides by pure luck?

no map updates?
 

How do you find a target with map updates off besides by pure luck?:hmm:

Presently my current patrol is in 44', so I have Radar to find my targets. But besides that, if you patrol along known shipping routes you will hit paydirt eventually. Also pay attention to radio messages. There may be info of a convoy or taskforce. And of corse don't forget periodic hydrophone checks, especially if you don't have radar.

Weeeeew~ Thanks for this. I will print this out and giver 'er a read.