Basic question re the TDC in ATO/KIUB mod

[I'm goin' down]

Here is a copy of a portion of a PM exchange between Wilcke and me. It illustrates the issue I am having with KIUB.

Captain Wilcke:

"Ok, its technique, you need to see a video of the shot, once you see that the KM KiUB is a lethal point and shoot.

Once I have course and speed, I go ahead of target and setup 800m at a 90 degree angle to targets course. If its a port shot, I set the periscope 15 degrees off my bow to the right, towards the approaching target. I then turn off the TDC by pressing on the edge of the blue light, set AOB to 75 degrees port( 90-15=75), set my speed and range dials appropriately, turn the TDC back on, blue light is lit.

I setup my torpedos and I can sit and follow the sonar mans calls until its time for me to shoot. When ready I raise the scope and wait for target to cross the periscope wire and shot for the king posts, two shots and your done. Down scope and wait for the boom.

The thing is so accurate, that if I have one hit and one dud, I just turn the TDC off adjust the speed for the slowing target turn it back on and re-aim the scope just a bit ahead of the now slowing target and shoot for the kingpost that did not get hit. At this range even after the target has crossed your bow and is moving away the TDC can still hit at 800 meters.

I have to find a tutorial, even an old one would work for you."

My reply, which pretty much says it all:

"Here is my question. In your example, you point the scope to 15 degrees (target's port side), deactive the blue light (which turns off the TDC) and set the Aob dial to 75 degrees. The next part of your explanation confuses me. If you reactive the TDC (turn the blue light on), won't the TDC begin tracking the target even if it has not reached 15 degrees (i.e. say the target is at 20 degrees when you reactive the blue light and at that bearing will not cross the wire until it reaches 15 degrees.) In PTO the TDC still tracks the target when it is in the deactived positon (i.e. the PK is turned off). In OM, by contrast, you are advising to turn on the PK, and apparently you are indicating that the TDC will not move if the periscope remains 15 degrees. And, what happens if, after the forgoing is set up and the periscope is moved to a new posiiton, say 5 degrees?"

It seems from Wilckes explanation that the TDC locks on the target at 15 degrees but does not track the target. This seems to also be what Capn Scurvy says in his tutorial on the his brand spanking new OTC mod, where he notes that the German UBoats did not have a Position Keeper to update the TDC. If this is correct, then tracking a ship on the TDC in ATO is not possible. In such as case, Wilcke's attack instructions, i.e. shooting when the target crosses the wire, are pretty much the preferred attack method. Kasmaronov (spell?) talks about firing with a zero gyro angle, but I will deal with that method when I understand what is going on with the TDC. So far I have not hit a moving target. Also, assuming Wilcke is correct, is the preferred target bearings for an firing torpedoes between 345 and 15 degrees? Or can an attack proceed at other angles?

BTW. I saw a one hour special on the Battle of the Atlantic. It dealt with Doenitz's wolf packs in 1943 and 1944, UBoat limitations, allied countermeasures to the various German submarine tactics that evolved in response thereto, plus interviews with German, Canadian, British and American sailors and sub hunting allied pilots who lived through it. This was the turning point in the Battle of the Atlantic.

By the time Doenitz incoporated the snorkel so his boat would not have to surface frequently to charge batters, and the German introduced better armored subs that could dive deep and were more likely to survive depth charges dropped from destroyers and aircraft, it was too late. The casualty rate for UBoat crews was 75 percent, the highest of any branch of the German armed forces. Doenitz was designated fuhrer by Hitler when he committed suicide, and succeeded Hitler. He did not believe he had done anything illegal, but was sentenced 10 years in prison for war crimes. The special did not detail the crimes against him. The special describes him as a committed Nazi, and pointed out that he was highly respected by his submarine corps throughout the war. His son was killed aboard a UBoat which was sunk in the Battle of the Atlantic.

The special takes the position that the allies were open to using ideas from any source to develop countermeasures to new UBoat tactics, but that the Germans did not. This diffeernce may have led to the ultimate defeat the UBoat fleet. For example, when UBoalts introduced magnetic torpedoes, which homed on a target's propeller, the allies countered by dragging a line behind their ships with an attacked device which created a great deal of noise and was intended to confuse the incoming torpedoes. The magnetic torpedoes went to for device, and ultimately proved to be ineffective. This was a simple, creative and low cost countermeeasure.

One interview with a German sub survivor was really interesting. His sub was sunk when it tried to enter the English Channel by sailing near the bottom of the Channel. His boat was part of the UBoat fleet sent to thwart the D-Day operatoin. Allied ships hunting UBoats had great difficulty tracking subs sailing near the ocean floor because it confused their radar (due in part to the presence of a variety of materials on the sea floor that reacted to radar signals.) The survivor escaped the sinking by dawning his oxygen mask and exiting the sub through a torpedoe tube. He was the only survivor of the sunken sub. He said on the way the surface he relived his entire life, every moment. He said he could not describe the experience or say why it happened, except to say that it was a real as the person sitting in the room with him doing the interview.