U-boat Tactics and the Radio Log Mod

[rudewarrior]

Hi Everyone,
I usually try to play this game as “realistically” as possible, within reason, e.g. when my u-boat goes down I don’t go drown myself in the bathtub.

One thing that I have attempted to do is play the tactics as issued by BdU as was actually occurring in the war. A good example is the requirement that only impact pistols were used in the beginning of the war. The problem I have been having is that I find it difficult to remember exactly what the conditions are when I am in-game. So I have been using the Radio Log Mod to try and determine what these conditions are. I have been able to break it down by categories to what I have at the end of the post, but I do have some questions about what is actually being communicated. I am also interested in any other conditions that might be appropriate for u-boat tactics as applies in-game. However, I have to operate somewhat in reason, as some conditions aren’t really appropriate to how the game operates. For example, the requirement that radio silence be maintained except when attacking, may be sacrificed, as the radio is minimally used anyway, and space will be limited for the personal mod that I will be making to add this so that I can refer to it in the game. So here is what I have so far broken down by category. I didn’t actually include the messages from the radio log in the interest of space. If you are interested in checking my info, or you want to just look at the message, I suggest you check the Radio Log to verify it.

Ultimately, I would appreciate any help with determining what actual conditions were, and I have added some notes to my explanations. Some of them are pretty easy to discern, some I have questions about, and I would really appreciate some help there. It is also to be understood that I am using the full Merchant Fleet Mod that allows for enemy shipping that has "neutral" markings.

France
9/3/1939 Defensive action against French Shipping.
9/24/1939 French shipping is now an eligible target.
Passenger Ships
9/4/1939 Passenger ships are not eligible targets. (This included the Passenger/Cargo ship)
9/24/1939 Small passenger ships are eligible targets. (Now Passenger/Cargo is eligible, but not liners)
10/27/1939 Liners sailing in convoy are eligible targets.
11/12/1939 Armed liners are eligible targets.
11/17/1939 " (I can’t tell if this message is any different)
2/23/1940 Non-neutral liners in "darkened" regions. (This seems to refer to the “Blockade” messages below, which I also have questions about)
8/17/1940 Hostile liners in the area around GB.
8/17/1940 Hostile liners up to 20 deg. West? (Again referring to “Blockade?”)
Torpedo Settings
9/8/1939 Impact pistols on ships < 3kT.
10/18/1939 Impact pistols only.
10/20/1939 Ships with drawing < 4m are not eligible targets.
11/10/1939 Magnetic pistols are standard.
4/12/1940 N of 62 lat. (Norway mission) 2 torps 8 sec. diff, one impact one mag.
5/23/1940 Impact pistols only. (When did this policy end?)
6/4/1940 "
6/1/1942 F.A.T. fired only at night. (Did this policy ever end?)
Capital/Combat Ships
9/7/1939 Naval ships are not eligible targets.
8/13/1941 Escort ships are priority. (Did this policy ever end?)
8/13/1941 "
Area of Operations
10/19/1939 Darkened ships extended to 20 deg. W. Sunk by torpedoes only.
10/29/1939 No surface approach of shipping in the North Sea to include W of Orkneys
1/6/1940 Submerged attacks in eastern coastal area A.
1/10/1940 Submerged attacks in English Waters.
1/12/1940 Submerged attacks in eastern coastal area A & B.
1/24/1940 Submerged attacks in eastern coastal areas A, B, & C.
1/24/1940 A extended 2 deg E, B S and SW to 10 deg W including Irish Sea.
5/24/1940 Submerged W of Scotland and off French Atl. Coast, zones E & F.
5/24/1940 "
7/31/1940 Patrol Areas designated in AN are no longer relevant.
7/31/1940 "
There is some general confusion about what these regions actually are. So extending the “darkened ships” region to 20 deg. W doesn’t really mean anything to me. Also what are these coastal area designations? As far as I can tell it is not related to the Kriegsmarine map system. The whole “sunk by torpedoes only” thing is a little confusing, too. So I can’t use the deck gun anywhere around Britain during these times? Why was this policy in place (out of curiosity)?
English Channel
11/1/1939 English channel is now off limits.
6/25/1940 English channel is now open. (When did this policy end?)
Norway Ops
3/2/1940 Atlantic ops suspended indefinitely.
3/5/1940 (Further U-boat sailings are to be stopped. U-boats which have already sailed are not to operate off the Norwegian coast) Does this really affect gameplay?
4/7/1940 Operation Hartmut begins.
4/26/1940 Cease Norway Ops.
Do tactics change for this (other than torpedo settings)? More specifically, does any of this actually effect in game tactics?
Radio
12/5/1940 Radio Silenced Except When Attacking
6/9/1941 Minimized Radio Usage
6/9/1941 "
Are these relevant to in game tactics? It seems the radio is used pretty minimally anyway, and as far as I know HF/DF is not included in the game.
US
4/1/1941 No US Ships under any circumstances.
5/1/1941 No US Ships under any circumstances.
5/1/1941 No US Ships under any circumstances.
6/20/1941 No US Ships under any circumstances.
6/21/1941 No US Ships under any circumstances.
6/21/1941 "
7/1/1941 No US merchant ships.
7/1/1941 No US merchant ships.
7/9/1941 No US Ships under any circumstances.
7/9/1941 "
7/12/1941 No US Ships under any circumstances.
12/9/1941 US Ships are eligible for attack.
Blockade
5/16/1941 Operations: The order given to the Western boats on procedure in the blockade area has been altered as follows on the instructions of the Naval War Staff:|Immediate action is permitted outside the blockade area:|In accordance with Standing war Order No. 101 paragraph II 4 b - d and 5. Against enemy merchant ships in neutral convoy. Warships sailing outside the blockade area, independent or as convoy escort, are only to be attacked if they are identified as enemy for certain or if darkened or if they take action first.||BdU

8/1/1941 |1941/08/01|Attacks are now permitted on all destroyers and smaller warships provided they are within the old German blockade area, declared on 17th August, 1940, whose boundary coincded with the U.S.A. Zone along the 20th meridian. Outside of this area, that is the new blockade area of 1st April, 1941, only clearly identifiable enemy warships may be attacked. As this can not be clearly established during the hours of darkness, warships with convoys, single destroyers, and A/S vessels may not be attacked at night outside the old blockade area, even if attacked.||BdU
I’m not sure if these actually have any implications. Some help here would be nice.
Bay of Biscay
6/24/1942 Submerged in BOB.
5/1/1943 Submerged in BOB, but recharge in daylight, and fight aircraft on surface.
5/1/1943 "
8/2/1943 In BOB, proceed along Spanish coast, Metox off.
8/2/1943 "
8/27/1944 N/A (^Deutsche Kräfte auf See^ The area off the Biscay ports is no longer to be a field of operation owing to lack of counter-measures to the extensive mine and air danger and search groups.||BdU) (It seems that this really doesn’t effect in game behavior.)
Is there more information to supplement these policies? I know that crossing the BOB became problematic during the war and tactics were changed, such as using U-Flaks (that also aren’t in the game), so is there a good way to deal with this?
Other
9/7/1941 Italian based U-boats must go to French bases for repair. (Can this even be simulated?)
2/7/1943 Outrun corvettes on surface to. Engage aircraft on surface during daytime
2/7/1943 only dive when ocean depth is 80+ m. (This is a complex order, also when did this policy change?)
12/4/1943 No single vessel attacks in area encompassed by EF63-EH63-DE36-DD24 (When did this policy end?)
12/28/1943 Attempt to fire at a depth ~20 m preferably with F.A.T's or Zaunkonigs.
12/28/1943 "
12/28/1943 "
12/28/1943 " (I couldn’t tell from this message if this was or was not actually implemented. It seems from the message that is what they wanted to move to, but I can’t really see it being successful, nor a method that would be used for long)
1/26/1944 After firing Zaunkonig torps, dive to 30+m.
12/14/1944 In coastal waters operate at perisope depth during the day, but with
12/14/1944 minimal radio contact. (Can this be feasibly done in game? )

Ultimately this idea is still somewhat in its beginning stages, so any enlightenment would be helpful.

[Sailor Steve]

Good list! I use the full radio log, but you're right; sometimes it is hard to remember what the last order was, and they change a lot early in the war. I'll try to address a couple of your concerns if I can. Also remember you might miss some because you were submerged when they were sent.

Originally Posted by rudewarrior

France
9/3/1939 Defensive action against French Shipping.
9/24/1939 French shipping is now an eligible target.

I've seen it go back and forth several times, and until the end of 1939 it can get quite confusing. I wonder how the real kaleuns felt about it.

11/17/1939 " (I can't tell if this message is any different)

Did you quit and restart at any point? When you reload the game the most recent messages are repeated, always using your current date.

I can't answer the "blockade" questions, mainly because I didn't pay attention in class.

9/8/1939 Impact pistols on ships < 3kT.
10/18/1939 Impact pistols only.

Note that at this time there was no switch. Shutting off the magnetic pistol required taking the head off the torpedo and removing it manually, a job requiring at least an hour for each eel, plus time spent swapping them out of the tubes or racks. It was only a couple of days ago that I came across the document which verifies the date they got the switches. Until I read that I thought there never was one.

5/23/1940 Impact pistols only. (When did this policy end?)

December 1942, with the arrival of the new, improved magnetic pistol (and the aforementioned switch). They were assigned to boats as they returned from patrols following that date, so probably your first patrol starting in 1943.

8/13/1941 Escort ships are priority. (Did this policy ever end?)

Can't say for sure, but I'm pretty certain that merchants were always the number one target. It couldn't have lasted long.

There is some general confusion about what these regions actually are. So extending the "darkened ships" region to 20 deg. W doesn't really mean anything to me. Also what are these coastal area designations? As far as I can tell it is not related to the Kriegsmarine map system.

There are several messages referring to coded locations that I haven't figured out either. I'm sure someone will come along with the right references and make me feel silly for not knowing that.

The whole "sunk by torpedoes only" thing is a little confusing, too. So I can't use the deck gun anywhere around Britain during these times? Why was this policy in place (out of curiosity)?

Twenty degees west is the North Atlantic north and south of Iceland. I would guess that at night a darkened ship might be anything, and other escorts might be near, so the order was to protect the boats from unpleasant surprises. But that's just a wild guess. As for no surface attacks in the North Sea, that was probably because of increased air patrols close to the British coast.

11/1/1939 English channel is now off limits.
6/25/1940 English channel is now open. (When did this policy end?)

Again guessing, but the date would indicate an order to attack shipping aiding the Dunkirk evacuation, so it probably didn't last past the end of June.

3/5/1940 (Further U-boat sailings are to be stopped. U-boats which have already sailed are not to operate off the Norwegian coast) Does this really affect gameplay?

Not that I'm aware of.

Do tactics change for this (other than torpedo settings)? More specifically, does any of this actually effect in game tactics?

No. All these messages are for immersion only. You are free to do whatever you want in the game.

Are these relevant to in game tactics? It seems the radio is used pretty minimally anyway, and as far as I know HF/DF is not included in the game.

Not in the least. In real life every u-boat was to make a position report at the same time every day. Far from being minimal, German radio traffic was quite heavy. One of Doenitz's biggest mistakes was his penchant for micromanaging his u-boats.

As for huff-duff, I don't know.

I'm not sure if these actually have any implications. Some help here would be nice.

BdU's orders were often confusing even to the real kaleuns. They mean nothing in-game. None of these messages have any effect on the game.

Is there more information to supplement these policies? I know that crossing the BOB became problematic during the war and tactics were changed, such as using U-Flaks (that also aren't in the game), so is there a good way to deal with this?

In GWX and I'm pretty sure the other supermods the Bay of Biscay does become quite dangerous. In real life the policy was a failure, and the u-flaks got their hats handed to them. The order was quickly rescinded.

9/7/1941 Italian based U-boats must go to French bases for repair. (Can this even be simulated?)

Don't know. Someone who has played a Med campaign should be able to help here.

2/7/1943 Outrun corvettes on surface to. Engage aircraft on surface during daytime

Stupid order. Yes, you can outrun a corvette, by one knot in a Type VII and two knots in a Type IX. Aircraft? Forget it.

2/7/1943 only dive when ocean depth is 80+ m. (This is a complex order, also when did this policy change?)

Common sense. Though gamers can hit different buttons to affect crash dives, in real life a crash dive meant a full flooding of the tanks. Seventy meters was an average pull-out depth.

12/14/1944 minimal radio contact. (Can this be feasibly done in game? )

They finally figured out that the Brits were reading their mail, and they finally tooks steps to stop it. In-game? Well, if you're like me and actually send a position report every day it might make a difference. If you never call home, probably not.

Ultimately this idea is still somewhat in its beginning stages, so any enlightenment would be helpful.

Gave you what I could for now. I like the idea.

[andqui]

I've been going throught the KTB and standing orders, and this is what I have come up with so far. I've only gotten up to the fall of 1941. My own shorthand about missing things are included, and if anyone can fill me in on some of the details, feel free.

Prize rules: (London 1936 Submarine agreement)
1. With any merchant, surface and order to halt, boarding party checks for contraband. Exempt: Escorted, refuse inspection, troop/military transports
Prize rules disbanded by May 1940, when exactly|||||NEED INFO

Torpedo settings:
Early 1939 to October 2, 1939: Torpedo fuses are only set in patrol- can't be changed
Sep 14, 1939: All targets under 3000 tons to be attacked with impact
Sep 18, 1939: No magnetic shots
October 7, 1939: Magnetic fusing allowed with TII, TI still use impact
October 19, 1939: Impact only
November 1, 1939: Torpedoes run up to 2 m deeper than set. Set depth 2 m less than draft. Depth must be at least 3 meters, 4 m in big waves. Coup-de-grace must be set at 3 m. Means five m is the minimum draft to engage a target.
November 8: New magnetic pistol introduced. Magnetic shots to be used, depth to draft minus 1 meter. Impact only on TI fast.
January 20, 1940: Magnetic fusing: All targets less than 40,000 use 4 m depth. Targets under 1000 are not to be magnetically attacked. All targets greater than 4000, use draft plus 1
March 14: No magentic shots E of 30 degrees longitude (needs confirmation)
March 19: Fast speed on G7a forbidden. Use impact in situations where boat's concealment is essential. Same magnetic depth rules apply. Minimum distance is 500 meters. 9 seconds between magnetic fan shots, no double shots
April 11: Boats in zone O and north: Keep three bow torps set impact, one with magnetic. Attack large targets with impact a 2 meters. Double shot against destroyers, with impact at 3 meters and magnetic shots at draft-1 8 seconds later. No change for southern Norway area
April 17:	1. G7a probably runs 2+ meters deeper than set.
		2. Zone O: Fire with magnetic, except inside of fjords
		3. Magnetic: No salvoes, and at least 8 second interval between shots
		4. Magnetic. Set depth to draft, 4 meters v destroyers, 3/4 m against submarines. Impact to 4 meters, 3 in good wx.
April 21: TII: Magnetic set depth to draft-1 meter. Against targets under 4000, set to 2 m in good weather, 3 m in bad. For impact, 3 meters against all, 2 in good wx. TI is same except for minimum depth 3 meters. All capital ships attack with 5 meters impact.
June 1: Abandon magnetic fusing, impact only. April 21 depth rules apply. Try for shallow angle hits if possible- 30 degrees is optimal
June 4: Depth to draft-3 meters, not shallower than 3 m (running depth partially fixed?). Torpedo depth has been largely corrected, +_1 m can be expected.
June 20: G7a high-speed allowed again. Set depth to draft-3, and not shallower than 3 (2 in good wx). Destroyers can now be attacked
July 30: G7a high-speed banned again (WHEN ALLOWED AGAIN?)
Feb 1942: Torpedo depth keeping completely fixed|||||DATE? Maybe May 1942?
WHEN ARE MAGNETICS REINTRODUCED? (Paper says Nov 1942 tests in the mediterranean, by April 1943 standard) 

1939
Sep 1: All Polish Vessels to be attacked, no attacks on English except for defense

Sep 3: Engage British warships, merchants with prize law. Evening, French ships are targets, do not attack French merchants

Sep 4: Reiterate no action at all against passenger vessels

Sep 6: No action against anything French at all

Sep 7-Sep 12: No attacks on capital ships (Does this really end Sep 12? Sep 12 is guess based on when Courageous was sunk)

Sep 10: Enemy convoys may be attacked north of Brest, even if they include French forces. No passenger ships, even if under escort.

Sep 24: French ships are valid targets (Channel troop transports can be attacked). Passenger order still in force.

October 2: Narrow area around England where darkened ships may be attacked without warning. No attacks in baltic and North Sea. PAX ship is one with 120+ passengers, 4 or more lifeboats along side, promenade decks, etc

October 4: Darkened ships attacked w/out warning zone extended to 15 west. Any armed vessel can be attacked without warning, PAX ships not included. Save crew w/out endangering boat.

October 5: Baltic approaches between Abelo and Skagen, submerge by day due to enemey s/m

October 27: Prize rules: No boarding, sink with torpedoes (no guns/scuttling)

October 29: PAX ships in convoys are valid targets. Keep distance in any gun action.

November 17: Armed PAX ships are valid targets

December 4: No using the Channel
//1940

Mid/Late March/early April: Weseruebun: No attacks on merchants, radio silence. Warships and screening are priority, remain undetected.

April 12: Norway Uboats attack all targets (not just warships/troop transports)

April 20: All uboats pull out of zone O due to torpedo failures

//1941
April 4, 1941: Unrestricted submarine warfare against all vessels in England blockade area- excepting Finnish and RUssian

May 8: At sea refueling only during night

May 16: Cleared to attack without warning (outside blockade zone):
	1. British merchants, not including unarmed/unescorted PAX ships (120 passenger rule)
	2. French/Norwegian/Dutch/Belgian ships which are armed
	3. All darkened ships
	4. Only warships if absolutely identified as enemy or darkened
	Make efforts to rescue crew provided no danger to boat

June 20: Only attack US Warships if they are 20 or more nm inside of the eastern boundary of the blockade area.

June 21: No incident at all with US forces. Only attacks on warships will be on bb, ac, or cruisers and only if recognized as enemy. Darkened warship does not count as enemy.
//AMERICAN SAFETY ZONE- where?

To mirror the torpedo depth problems, I'm using this SH3 commander mod, see post #17.
http://www.subsim.com/radioroom/show...=158642&page=2

[HW3]

There is some general confusion about what these regions actually are. So extending the "darkened ships" region to 20 deg. W doesn't really mean anything to me. Also what are these coastal area designations? As far as I can tell it is not related to the Kriegsmarine map system.

This map might be of some help. I do not remember where I found it.

[Sailor Steve]

Good job!

[rudewarrior]

@HW3: Great work, I have been looking around to see if I can figure out where you found it. No luck, tho. I'll keep looking to try and find more info anyway.

@SS: Thanx for the info, your commentary helps a lot!

@andqui: Wow! That is some fantastic work! It looks like pretty boring research tho. Is there any way I can help? Two of us working on it might lighten the load.

[andqui]

Here is the website with standing orders and the official war diary:

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

As for working together, maybe it would be simplest if I keep going from where I am, and you start in Jan 1945 and work backwards? We're just looking for any SOP's with the appropriate dates they are in effect.

The hard part is often finding when certain orders ended- for example, in your collection, you have an entry about hugging the French/Spanish coast with RWR off in order to avoid Biscay- this was the Piening Route.
http://www.uboat.net/maps/piening-route.htm
When did it stop being used? That link says it was around briefly until the Spanish gov't started following the rules a bit more. Also from your compilation, there is mention of an order to stay and fight a/c on the surface- http://www.uboat.net/history/fight_back_order.htm. This lasted for 97 days, and only applied to boats with a wintergarten platform. Anyways, hopefully more details come up the further I go through the war diary.

[rudewarrior]

Originally Posted by andqui

As for working together, maybe it would be simplest if I keep going from where I am, and you start in Jan 1945 and work backwards? We're just looking for any SOP's with the appropriate dates they are in effect.

Roger that! I'll start looking at it this afternoon.

[Iron Budokan]

That is an awesome list! Thank you for compiling that for us, I think it will be quite helpful on future patrols.

[rudewarrior]

@andqui: Just a quick update. I've gotten up to July '44, going backwards from January '45.

[andqui]

Good to hear. I'm up into Feb 1942.

[FIREWALL]

Originally Posted by HW3

This map might be of some help. I do not remember where I found it.

I saved pic to my SH3 folder. Will print for use with other maps I have.

I hope you upload it in SH3 Downloads. At the bottom there's a section for maps, documents and, other usefull stuff.

[HW3]

I would but, not remembering where I got it from means I can't give proper credit for it, so I won't upload it.

[rudewarrior]

@andqui: I'm up to March '44. I'll PM you with any other updates. I have some ideas for this mod I wanna share.

[rudewarrior]

Originally Posted by rudewarrior

Area of Operations
10/19/1939 Darkened ships extended to 20 deg. W. Sunk by torpedoes only.
10/29/1939 No surface approach of shipping in the North Sea to include W of Orkneys
1/6/1940 Submerged attacks in eastern coastal area A.
1/10/1940 Submerged attacks in English Waters.
1/12/1940 Submerged attacks in eastern coastal area A & B.
1/24/1940 Submerged attacks in eastern coastal areas A, B, & C.
1/24/1940 A extended 2 deg E, B S and SW to 10 deg W including Irish Sea.
5/24/1940 Submerged W of Scotland and off French Atl. Coast, zones E & F.
5/24/1940 "

Quoting my own post, but does anyone know what the original source for these messages are? I can't find them in the KTB's (well the first two are, sort of, and the others aren't), and I have spent a week looking for them all over the Internets. Is there anyone that can point me to the original source of these particular messages? I would really like to get some context.

Thanx in advance.