Immersive techniques for the true subsimmer!

[Storm501]

I was on patrol on international waters. My IWO sights a neutral passenger liner. I consult BdU orders as we have unrestricted submarine warfare and possibility to engage. I am also in an operation with focus on warships and troop transports. After long consideration I decide not to sink her. I only snatch a small ID photo. 15 min later it feels dissapointing to let a 8000t target go...

For some reason I keep coming back to this photo. So after the patrol I decide to try and find out the name of the ship. I Google "Swedish passenger liner". The 2nd result leads me to a Wikipedia article and the similarity is clear as day.




Just amazing. They match almost perfectly. Here is a bit of the article: https://en.wikipedia.org/wiki/SS_Drottningholm

The Drottningholm was one of the few passenger liners along with Cunard's RMS Aquitania, to have completed service in both World Wars. During wartime the ship was used as a mercy ship to exchange civilian internees, POWs, and diplomats. She was chartered by the American, British, and French governments for a total of 14 voyages that transported 18,160 individuals.
In March 1942 the ship was chartered by the U.S. State Department via an arrangement with the Nazi Germans and other Axis powers, facilitated with the help of the Swiss and Swedish governments, to repatriate civilian internees and diplomats from both sides of the war. Her first east bound voyage from the US, carrying Axis individuals, was from New York City to Lisbon, Portugal on May 7, 1942. On May 22, she departed Lisbon for a west bound return trip carrying Allied individuals to New York, arriving on June 1, 1942. The passengers included American Chargé d'affaires to Germany Leland B. Morris and diplomat George Kennan. She made one more east bound voyage to Lisbon on June 3 from Jersey City, New Jersey. Her final west bound exchange mission from Lisbon to New York arrived in the United States on June 30. That would be her last exchange trip from Lisbon as the Nazi government cancelled all further trades. On July 15, she left from New York City to her home port in Gothenburg, Sweden, carrying approximately 800 Axis nationals.
She continued to serve the British and French as a repatriation mercy ship. The Drottningholm carried Red Cross supplies for distribution to other nationalsstill in Japanese controlled territory. One Japanese national jumped overboard and drowned causing the exchange to be halted until an American offered to stay in captivity.

The Drottningholm was painted white with the name of the vessel in very large letters, the Swedish flag and the words "Sverige" (Sweden) and "Diplomat" painted prominently on port and starboard. She was fully illuminated so her markings could be easily viewed. On 16 March 1944 she docked in New York after an exchange voyage that took 750
Germans to Europe in exchange for 600 wartime internees, including Mary Berg. In September 1944, she was being used by the Red Cross to transport POWs and civilians being repatriated from Germany to the UK via Sweden, under the command of Captain John Nordlander. Another voyage in April 1945 docked in Liverpool that included 212 ex-interned Channel Islanders.

This is just the ww2 history. The ship transported Canadian troops during ww1 and was involved in the disaster of the Titanic.

So now having learned the story of the ship in the sights of my UZO, I am glad I didn't sink her. Without learning the story I would have just thought "another neutral wasting my time in the game". So this brings a lot of new feeling to the game. How big of a responsibility a U-boat commander has on the decision to sink a ship or not. On that night I did not observe any diplomatic markings. Had I sunk her, I would have been in so much trouble. If it were not possible to cover the sinking as a mine.. With my decision, hang in the balance a big international incident, which would effect relations between Germany and Sweden. Perhaps on a strategical scale in ww2. But now I can be glad I made the right choice. I can put this ship in my photo album, marking down where and when I met her. Next we encounter, I will recognize her quite instantly.

[Aktungbby]

CONGRATS and kudos to your reticence as the anger Swedes woul blow up their iron mines and hamper the Nazi war effort in retaliation: a principle reason Hitler never invaded Sweden as with Denmark and Norway.https://en.wikipedia.org/wiki/Sweden_during_World_War_II

From late 1942 and into 1943, Germany began to meet with a series of military reverses after its losses at the Second Battle of El Alamein, the Battle of Stalingrad and elsewhere. Germany was forced into a more defensive position as the Allied forces achieved success on the battlefield. It was becoming increasingly apparent to Sweden that Germany was unlikely to win the war. Prior to 1943, Sweden's policy of neutrality had been largely under the close scrutiny of Germany. After August and September 1943, however, Sweden was increasingly able to resist German demands and to soften its stance to Allied pressure. However, despite Germany's new, defensive posture, Sweden's constant fear was that the unexpected would happen, an attitude that continued until the very end of the war. With Germany's weakening position came stronger demands from the Allies. They pushed for Sweden to abandon its trade with Germany and to stop all German troop movements over Swedish soil. Sweden accepted payments from the Allies to compensate for this loss of income through reduced trade with Germany, but continued to sell steel and machine parts to Nazi Germany at inflated smugglers' rates.

[Storm501]

Another example illustrated. Here is the OPS room... or more like a corner. I just finished out piecing U-boat, convoy, task force and airbase symbols.
A while back I also covered the map with transparent plastic sheets, so that I could draw lines and circles. Air base range rings and convoy routes would be awesome, but it increases the workload and they change over time... In the paper sheet below I had BdU orders for the patrol, like the assigned grid.

Now considering if I could do something differently. For example compiling some sort of intel/planning/moon stage/weather package on the kneeboard before every patrol would be awesome. I think it would be feasable to add other U-boat symbols to the map, whenever they report, so it helps with the big picture. Even though it is just flavour.

[derstosstrupp]

Let’s keep this thread alive! Here’s one I did today showing a historical approach as one would typically read in the KTBs:

[Macgregor the Hammer]

Where can I find GOOD translations of KTB's?

[derstosstrupp]

Originally Posted by Macgregor the Hammer

Where can I find GOOD translations of KTB's?

These are mostly good. Few errors here and there but nothing major.

http://www.uboatarchive.net/KTBList.htm

[les green01]

i do love reading this thread many great pointers and to know i'm not the only one that plays like this

[derstosstrupp]

Here are the myriad orders, particularly early war, with regard to detonator settings, as Germany struggled to reconcile the various torpedo problems. Not for the faint of heart!

Source is “Wolves Without Teeth: The German Torpedo Crisis in World War Two“ by David Habersham Wright.

MZ = magnetic detonator (“Magnetzünder”)
AZ = impact detonator (“Aufschlagzünder”)

At patrol start:
- Before Oct. 2 1939, your pistols are either set to MZ or AZ and cannot be changed during patrol. Randomly determine what eels are set to what. It was however possible to swap out pistols between torpedoes, so keep that in mind.

- After that date, decide when loading each eel into a tube what you want the setting to be (keeping the standing pistol orders in mind). No switching during attack!

- Roughly 75% of all torpedoes fired were G7e. This was the standard torpedo of the war, and cheaper to produce. Use a random number generator or dice to determine the type of each torpedo you get, 75% chance of each being G7e up to the following limits. For Type VIIB or C, you can load max 9 G7e (all tubes loaded with G7e, and 4 in bow internal storage). For VIIA, max 8 (bow tubes loaded with G7e, and 4 in bow internal storage). Unmentioned slots of course get G7a.

War start:
Torpedoes had the Pi1 pistol and had either MZ or AZ preset, which could not be changed during patrol (unless the pistols themselves were swapped between torpedoes). Leadership put its faith in MZ, so this was preferred due to the devastating results of exploding under the target’s keel. No limit on MZ use at this time.

Sept. 15, ’39:
For targets < 3,000 tons, use only AZ. Larger targets have a greater magnetic field sufficient to detonate the warhead.

Sept. 17, ’39:
Premature detonations continue. BdU forbids MZ. Use only AZ. Note that, since pistol settings could not be changed during patrol, these are odd orders, likely born of Dönitz’s frustration.

Oct. 2, ’39:
“Schalterstellung A” (switch position A) introduced, allowing the pistol settings to be switched on patrol between MZ and AZ, allowing the mandatory AZ setting to be set. [boats at sea during this time will be fitted with torpedoes with this on next patrol]

Oct. 11, ’39:
The torpedo inspectorate recommends a new cable layout in the torpedoes, and BdU allows MZ use again. [boats at sea during this time will be fitted with torpedoes with this on next patrol]

Oct. 18, ’39:
BdU forbids MZ again after U-46 reports multiple premature detonations.

Nov. 1, ’39:
Set depth 2 meters shallower than target draft due to deep-running torpedoes, but no shallower than 3 meters (4 in strong Atlantic waves). Finishing shots on stopped steamers depth setting 3 meters.

Nov. 8, ’39:
New pistol Pi a+b created with a reworked MZ detonator. Dönitz allows MZ firing again, but not with the G7a “fast” setting of 44 kn. Depth for MZ to be draft + 1 meter. [boats at sea during this time will be fitted with torpedoes with this on next patrol]

Jan. 18, ’40:
Targets < 4,000 tons use depth setting of 4 meters. All other targets use ship’s draft + 1 meter.

Mar. 19, ’40:
G7a fast setting of 44 kn forbidden. Only AZ setting allowed in cases where the boat absolutely must remain hidden. If boat’s position becomes compromised, OK to use MZ (as the consequence of premature detonation is not so dangerous then). Minimum torpedo run of 500 meters with MZ. Separate multiple shots by 9 seconds. Set depth 4 meters for all targets < 4,000 tons and destroyers.

Apr. 11, ’40 (for boats in Norway campaign):
Keep forward tubes ready with 3 eels set to AZ and one to MZ. Attacks against large targets are to be with AZ, depth setting 2 meters.

Apr. 18, ’40:
Norway campaign boats no longer use AZ except in narrow fjords. With MZ, set depth equal to draft, 4 meters against destroyers, 3-4 meters against submarines. With AZ, set 4 meters, 3 meters in good weather.

Apr. 21, ‘40:
MZ shots depth target draft + 1 meter. Against destroyers, subs, and steamers under 4,000 tons, set 3 meters in bad weather, 2 meters in good. For AZ, 3 meters against all targets, 2 meters in good weather. Against capital ships, when firing AZ, set depth 5 meters.

Jun. 1, ‘40:
MZ firing forbidden (would remain so until late 1942).

Jun. 20, ‘40:
G7a fast setting of 44 kn again permitted. Depth to be set as draft minus 3 meters (2 meters in excellent weather).

Jul. 30, ‘40:
G7a fast setting again banned. The need for higher torpedo production meant that improved torpedo engines could not be installed.

Nov. ‘42 (in Med) or Dec. ‘42 (in Atlantic):
The Pi2 pistol is introduced, correcting the MZ problem. [boats deploying to these areas after these dates are assumed to have the new pistol]

[John Pancoast]

Originally Posted by derstosstrupp

Here are the myriad orders, particularly early war, with regard to detonator settings, as Germany struggled to reconcile the various torpedo problems. Not for the faint of heart!

Source is “Wolves Without Teeth: The German Torpedo Crisis in World War Two“ by David Habersham Wright.

MZ = magnetic detonator (“Magnetzünder”)
AZ = impact detonator (“Aufschlagzünder”)

At patrol start:
- Before Oct. 2 1939, your pistols are either set to MZ or AZ and cannot be changed during patrol. Randomly determine what eels are set to what. It was however possible to swap out pistols between torpedoes, so keep that in mind.

- After that date, decide when loading each eel into a tube what you want the setting to be (keeping the standing pistol orders in mind). No switching during attack!

- Roughly 75% of all torpedoes fired were G7e. This was the standard torpedo of the war, and cheaper to produce. Use a random number generator or dice to determine the type of each torpedo you get, 75% chance of each being G7e up to the following limits. For Type VIIB or C, you can load max 9 G7e (all tubes loaded with G7e, and 4 in bow internal storage). For VIIA, max 8 (bow tubes loaded with G7e, and 4 in bow internal storage). Unmentioned slots of course get G7a.

War start:
Torpedoes had the Pi1 pistol and had either MZ or AZ preset, which could not be changed during patrol (unless the pistols themselves were swapped between torpedoes). Leadership put its faith in MZ, so this was preferred due to the devastating results of exploding under the target’s keel. No limit on MZ use at this time.

Sept. 15, ’39:
For targets < 3,000 tons, use only AZ. Larger targets have a greater magnetic field sufficient to detonate the warhead.

Sept. 17, ’39:
Premature detonations continue. BdU forbids MZ. Use only AZ. Note that, since pistol settings could not be changed during patrol, these are odd orders, likely born of Dönitz’s frustration.

Oct. 2, ’39:
“Schalterstellung A” (switch position A) introduced, allowing the pistol settings to be switched on patrol between MZ and AZ, allowing the mandatory AZ setting to be set. [boats at sea during this time will be fitted with torpedoes with this on next patrol]

Oct. 11, ’39:
The torpedo inspectorate recommends a new cable layout in the torpedoes, and BdU allows MZ use again. [boats at sea during this time will be fitted with torpedoes with this on next patrol]

Oct. 18, ’39:
BdU forbids MZ again after U-46 reports multiple premature detonations.

Nov. 1, ’39:
Set depth 2 meters shallower than target draft due to deep-running torpedoes, but no shallower than 3 meters (4 in strong Atlantic waves). Finishing shots on stopped steamers depth setting 3 meters.

Nov. 8, ’39:
New pistol Pi a+b created with a reworked MZ detonator. Dönitz allows MZ firing again, but not with the G7a “fast” setting of 44 kn. Depth for MZ to be draft + 1 meter. [boats at sea during this time will be fitted with torpedoes with this on next patrol]

Jan. 18, ’40:
Targets < 4,000 tons use depth setting of 4 meters. All other targets use ship’s draft + 1 meter.

Mar. 19, ’40:
G7a fast setting of 44 kn forbidden. Only AZ setting allowed in cases where the boat absolutely must remain hidden. If boat’s position becomes compromised, OK to use MZ (as the consequence of premature detonation is not so dangerous then). Minimum torpedo run of 500 meters with MZ. Separate multiple shots by 9 seconds. Set depth 4 meters for all targets < 4,000 tons and destroyers.

Apr. 11, ’40 (for boats in Norway campaign):
Keep forward tubes ready with 3 eels set to AZ and one to MZ. Attacks against large targets are to be with AZ, depth setting 2 meters.

Apr. 18, ’40:
Norway campaign boats no longer use AZ except in narrow fjords. With MZ, set depth equal to draft, 4 meters against destroyers, 3-4 meters against submarines. With AZ, set 4 meters, 3 meters in good weather.

Apr. 21, ‘40:
MZ shots depth target draft + 1 meter. Against destroyers, subs, and steamers under 4,000 tons, set 3 meters in bad weather, 2 meters in good. For AZ, 3 meters against all targets, 2 meters in good weather. Against capital ships, when firing AZ, set depth 5 meters.

Jun. 1, ‘40:
MZ firing forbidden (would remain so until late 1942).

Jun. 20, ‘40:
G7a fast setting of 44 kn again permitted. Depth to be set as draft minus 3 meters (2 meters in excellent weather).

Jul. 30, ‘40:
G7a fast setting again banned. The need for higher torpedo production meant that improved torpedo engines could not be installed.

Nov. ‘42 (in Med) or Dec. ‘42 (in Atlantic):
The Pi2 pistol is introduced, correcting the MZ problem. [boats deploying to these areas after these dates are assumed to have the new pistol]

Nice ! I may have to whip up a SH3C date files with these instructions for SH3 anyway.
Recently made some date files eliminating u-boats carrying topside torpedoes and so only Liberators and Avengers use FIDO torpedoes per historical orders.