Please give suggestions for Realism
 

I was wondering if there are stats available for the war that list the average tonnage sunk per mission for each type of sub. I'm interested to know the avg for a typeII and TypeVIIB especially.

Also would like suggestions on how to adapt my play style to get closest to actual tonnage averages in real life. I have some guidelines that I already use that I will list below.

As suggested by Sailor Steve I believe, I set my minimum reload time for the deck gun to 10 seconds using SH3 Commander. Someone else suggested to only use deck guns on ships that are 1.5 tons or less.

What I do now is I only use my deck gun to finish a ship that has been torpedoed. For a ship of 4 tons or more, I don't use my deck gun until it has two fish in it. For a ship less than 3 tons I will use my deck gun after it has 1 fish in it.

I only allow 10 rounds of HE to be fired at any given ship. Then my deck gun mysteriously jams. I only allow 2 ships to be finished off with guns per mission.

With patrols. I patrol my grid for 24 hours. Then I allow myself to patrol a grid up to 2 grids away from my patrol grid for 24 hours. Then I start back to base and take the shortest route, only engaging targets I meet along the way and not searching prime areas.

I engage merchants in the order that I discover them. No letting a small merchant go to save torps for a T3 tanker. If I do miss a ship of 3 tons or less, (rare occurance but it happens sometimes if I play when too tired) I do not take another shot at it. Over 3 tons though is grounds for lining up a second attack.

I don't target escorts in a convoy first s0 I can attack the merchants at leisure. Only will attack a DD if it has discovered me and is DC'ing me. Then I will try to slip away, but if I can't then I may attack it. How long I try to slip away depends on what mood I am in and if I need to save quick I am more apt to finish the DD in order to save.

No harbour raids. There was only one during the War. I play with crew transfers and malfunctions using SH3 commander.

I found this graph that compares tonnage sunk to u-boats lost. Its kinda hard to get a feel for tonnage per mission this way. I'm going to try to see if I can break this down into something easier to understand.

http://www.centroeu.com/uboote/effic.html

Clay Blair's two-volume tome Hitler's U-Boat War has appendices in the back that comprehensively list how many tons each boat sank on each patrol.

The average tonnage sunk by U-boats gets dragged down during the course of the war, because a lot of U-Boats came back empty-handed or never got to make an attack. The earlier in the war you commanded a U-Boat, the better your boat's averages probably were.

During World War II, some 1,171 U-boats were operational. Of these only some 325 actually carried out attacks on enemy shipping, sinking or damaging the enemy. Over 800 U-boats therefore, were used only on training duties, were never used operationally, or were used but failed to find or attack the enemy or were sunk before ever sinking a ship.

Total Allied shipping losses to U-Boats were in the order of 3,000 vessels representing over 14,000,000 tons. Over 4,000,000 tons of that shipping was sunk by the elite top 3% of the U-Boat commanders. Of all Allied shipping lost 70% was lost to U-Boat attacks. The vast majority of these losses, well over 2,600 vessels, were to torpedo attack alone or a torpedo attack followed by gunfire. Around 160 ships were sunk by deck gunfire alone.

Thanks for that great info Torplexed. Just what I was looking for. I just ordered a copy of that book by Blair online.

Obviously we all have to find our happy medium for game play. I'll read that book and see what types of tonnages the elite boats were getting and go from there. I know the tonnages per u-boat lost go way down as the war progressed. Just read that in the later stages of the war the average u-boat survived 3 missions. Ouch.

Blair's book is an excellent resource. Here's a scan from the appendices of the May 1943 patrols where things start to turn grim. It's an interesting comparison to 1940 where just about every boat is sinking tonnage.

http://neptoon.homestead.com/April-1943.jpg

Here is a gook link, probably a lot of people know already but what the hey. I'm still newbieish.

http://www.uboat.net/men/aces/top.htm

These are the top 34 aces. On 259 war patrols these 34 men sank 873 ships for a total of 4,825,554 tons. That works out to 3.3 ships sunk per patrol and 18,631 tons per patrol. Note that the top ace's name was Otto :rock:

I broke it down further and found that in 8 missions in a type VIIB, Otto avaerage 35,594 tons. His 8 missions in a Type II averaged 3,453 tons. Huge difference. He survived the war and passed away in 1998. There are audio files on that site where you can listen to his accounts of the war.


edit-thanks for the scan Torplexed, was posting the same time you put it up. :D More info. Great stuff.

Probably the best way to limit tonnage towards historical amounts is to limit the number of ships you find. Quite simply there are far too many ships in the game.

So, you can do things to reduce your detection effectiveness, or you can fiddle with the campaign files to remove ships. So far, I have been doing the former. I now almost never conduct a hydrophone search myself unless I have already learned about the contact through some other means (like my crew found it earlier, or I got a radio report). I run submerged at 32xTC when patrolling and leave it to my sonar operators to find targets. When surfaced, I patrol at 32xTC if in enemy airspace, or at a higher TC if there are not likely to be any enemy aricraft around. The higher TC reduces the number of contacts I make. (I am considering increasing my TC in enemy controlled space, because I think there may be too many aircraft as well.)

In the future I may edit the campaign files to reduce the percentage chance of random units spawning, and I will definitely get rid of those two-merchant unescorted mini-convoys which are just a giveaway of free tonnage.

Not quite. You're right in saying it was rare, but Prien's raid wasn't the only harbor attack. Albrecht Achilles of U-161 attacked Port of Spain, Trinidad in 1942.

I stand corrected. Also the St. Lawrence River in Canada was attacked several times because Canada devoted all resources to convoy escorts and only have maybe 5 units to Patrol the St. Lawrence entrance. These attacks were not planned and happened sometimes because The sub was experience difficulties in rough water and picked the river because the water was calmer.


@RoaldLarsen Regarding there possibly being too many planes. I think you may be right. I was checking reports of when subs were attacked from one of the sites I posted a link to earlier. The most attacks in a single mission I saw from planes was three. I didn't read them all but took a fair sampling. In game I have gotten 3 air attacks on a single day in 1939.

I had a look at the airstrike.cfg file and looks like this could easily be adjusted in there by changing the probability. The probability also goes up if you radio a report.

I play in the 16k environment. This helps give you a better chance to avoid the bombs from a plane because your WO sights the planes further away. This also gives me a greater chance to visually spot ships which I don't really want. I may go back to the 8k environment and decrease air strike probability to offset the fact that by the time my WO spots them they already are droping bombs.

There is a setting in Contacts.cfg for visual contacts but I think this is just for how the range is classified. Either short, medium or long. Not sure if it actually sets the limit on how far away my WO will spot them.

The Campaign.SRC file is beyond my grasp at this point. I think I could reduce the number of merchants by changing their Roster.cfg. There is a folder for each country that has every ship in it. I am thinking of moving back the availability dates of some of merchant ships for Britain. For example I could move the Granville Frieghter availibility to 1941 instead of 1939. Not sure i the game would just substitute another merchant ship or if this would actually lead to less ships being generated early on.

You gave me good ideas. I am going to back up all my game files and play around with this.

Something you could do is simply ignore the ships reports sent to you by bdu unless they're convoys. I am not sure how realistic it is at the moment that you get a sighting message for ships in your area so often.

I found the cfg file that affects this and changed the range of radio contacts from 250 to 100k and the important contacts(Convoys/task forces) from 750 to 250K

I also found the setting that effects range of visibility and after changing it my initial ship sightings on a clear day went from about 14500m to 8500m. Plus I reduced airstrike probability from 35 to 20. Left my hydro alone, because I like to use it myself and the reduced visibility and radio sightings should have a big effect.

Tested out a Sept 1939 mission from Kiel in a typeII. In a mission to grid AN47 (Not a great grid for ships) I found i neutral merchant and that was it. So I got skunked. Perfect, never got skunked before. I think the contacts may be as I like them now because things will pick up in early 1940 and once in a typeVIIB I will have access to better patrol grids.

I'll run at least 8 missions with it and see how it goes compared to real life tonnage during the same period in the same sub.

Something else you can try to increase your level of realism is to only load external torpedoes when the sea state is 6m or less. The stock game (& GWX too I think) allows you to load torpedoes in practically any kind of weather.

Which files, keys and values, please?

Personally i dont think there is an abnormal amount of ships in the game. You have to understand that most of the time that contact was made whether by hydrophone or visual, there were many factors that had to be accounted for before a U-boat commander could even think about making an attack or attempting an intercept. Here is just a small sample of what went into the equation.

(sea conditions)would affect a U-boats surface speed and thus their ability to overtake or intercept a target. Not accuratley moddeled into the game IMO.

(time of day) If during daylight hours had a much higher probability of being spotted on the surface.

(Fuel remaining)depending on how far away you are patrolling from your base had a dramatic influence and impact on how far away a Kaptain was willing to track distant contacts, especiallly if you were already mid patrol!

these are just a few, there are literally dozens of other factors that came into play.

You have to understand that in reality, during a typical patrol U-boat Kaptaind did recieve quite a bit of information about ship movements or convoy traffic its just that more than 50% of the time they were not in a favourable positon to prosicute these reports!

For visual sightings by your watch officer. Open data/cfg/Sensors.cfg in notebook.

Change this first setting called Visual range factor. What it is currently depends on if you are playing a mod or a stock game. Mine was at 0.5 and I changed it to 1.0
It appears that the higher the number the shorter the distance that your WO can see.

[SensorParameters]
; Sensors Detection Parameters

;Visual.
Visual range factor=1.0

Since this changed my WO sightings on a clear day from 14500 to 8500 I also edited what the WO considers as long range in the Contacts.cfg file.
Open data/cfg/contacts (see below) My medium was 8000 while my long range was 16000. I changed those to 4000 and 8000 respectively.

[ContactRange]
;under the (right) value a contact is considered as:
Short=1000 ;[m]
Medium=4000 ;[m]
Long=8000 ;[m]


For airstrike Probability open data/cfg/airstrike.cfg
There will be a line that reads something like:
Default Air Strike Probability=20

In my game this was 35 so I changed it to 20.

Be sure to copy the original files elsewhere just in case. I always uncheck the option in vista that reads "Always use the selected program to open this file" when I open in notepad.

Good point. I have also wondered what would happen if the sub had to emergency dive while removing the external torpedoes. I have had to do this and of course when I resurface the process of loading the externals just starts where it got left off. Its entirely possible that they could be lost altogether.

@ Oneshot/Onekill, those are all good points. Daytime attacks were avoided if possible. I am considering not using them after 1940. In my typeIIA fuel does often become the reason I have to return to base and with malfunctions on there have been times in bad weather where my top speed was only 8 knots.

There are also cases where a sub returns to base because of a crew member illness or injury. I have wondered how you maintain silent running if half your crew has colds or the flu.

Thanks, Otto!

Does anybody know what factor constrains the longest range at which a target can be seen?

I don't use a 16k environment mod because of my ancient graphics card. If I reduce the Visual range factor to 0.4, will the maximum range at which I can detect aircraft be increased, or will I just have a higher chance of seeing an aircraft which is far away but still within some maximum range that is established elsewhere?

@Otto Heinzmeir. You can also try this sometime, its what i do. If i recieve a contact on my map and its more than 100km away as a rule of thumb i do not attempt to track it down, UNLESS its on a general course heading to allow me an easy intercept. ie using very little fuel.

What I do is to arbitrarily divide the loading time into phases and then give myself options within each phase.

Phase 1. First 10% of loading rime. Crew setting up, torpedo still in storage. Options: A) Abandon gear. Stay on surface 30 seconds before crash dive, lose ability to load any externally stored torpedos for rest of mission. B) Stow gear. Stay on surface 3 minutes before crash dive. Wait three minutes on surface before next attempting to load this torpedo. C) Stay on surface until next phase.

Phase 2. 10% to 50% of loading time. Crew removing torpedo from stowage and positioning over hatch. Options: A) Ditch torpedo and gear. Stay on surface 2 minutes before crash dive; lose ability to load any externally stored torpedos for rest of mission. B) Ditch torpedo, stow gear. Stay on surface 5 minutes before crash dive; do not attempt to load this torpedo again this mission. C) Stay on surface until next phase.

Phase 3. 50% to 100% of loading time. Crew passing torpedo through loading hatch. No options. Stay on surface until torpedo loaded.

I'll have to respectfully disagree, though admit I do so on the basis of limited research.

All the factors you list are modelled by the game, though perhaps they don't have quite as much effect as they did in real life. In the game, sea state affects a U-boat's speed, light conditions affect chance of being visually spotted and fuel affects range.

I do not disagree very much about the number of radio contact reports. The number might be a bit high, but German naval SigInt (XB-Dienst?) and reconnaisance from other boats and aircraft resulted in a lot of radio contact reports. In fact I don't like mods that remove the colour of contact reports from the map, because in reality, those contacts would often be reported as enemy or friendly.

You seem to be arguing that in real life, u-boats saw as many ships as we do in-game, but they sank a much lower proportion. I take the position that they made fewer sightings than we do. Perhaps they also sank fewer per sighting. I have no opinion on that.

As for the number of sightings, I have read a couple KTB's and a few books. The number of sightings per day on my in-game patrols is higher than what I have read was actual experience. Also, while the number of convoys spawned in the campaign may be similar to historical, in real life the allies were using Ultra to route convoys around u-boats, so fewer were seen than is the case in-game.