[REL] patSH3r

[Fader_Berg]

http://cjw.tuxxor.net/patSH3r-medium.png
V 1.1.0

　
- [ supersubsonic ] -


- - -
　

patSH3r changes the way Silent Hunter III works by bringing new functionallity to the game. It uses a technique called code injection, which adds/replaces code in live memory while running the game. Thus it doesn't make modifications to any of the original game files. When the files belonging to this project are removed, the game is left as nothing ever happened.

While playing SH3 for some time now. I've been missing a major part of the game, where I wished that the crew actually made a difference. To day they don't. At least not to the extent I want it anyway. So that is where the main focus of the patSH3r project will be. ...to start with.



FEATURES:

Crew rotation

This patch apply a auto rotation feature to the crew, so you don't have to manage them in such detail as in the original. This method is still quite simple and needs development, but it works just fine for the purpose.


Range estimation fix

This fix is a further developed version of h.sies V15D (http://www.subsim.com/radioroom/showthread.php?t=174225) range estimation fix, (thanks for the info h.sie). It makes the respective officers qualification (watch/helms), experience and endurance influence the results of range estimations.

INSTALLATION:
Unzip the downloaded file and copy the two files (patSH3r.act & patSH3r.cfg) to the directory where your SH3 installations resides.
Open the patSH3r.cfg-file with notepad and change the values (enable/disable) the features as you wish.
Next time you start the game, the changes will apply.

CHANGELOG:

C h a n g e L o g
-------------------------------------------------------------------------------
V1.1.0
· Added crew rotation
· Removed V15D patch switching.

V1.0.1
· Corrected WP range estimation bug.
· Changed the range estimation calculation.
Before, the range estimation errors came in large chunks (e.g. -2000, 0,
+2000 for > 12000). Now they come as any one hundred meters in between.


Get your copy here (http://cjw.tuxxor.net/files/silent_hunter).

Best wishes

/FB

[nikbear]

So.... what does this do??:06:

[Magic1111]

So.... what does this do??:06:

Yes, that´s a very good question....:06:

I don´t understand the MOD from Fader_Berg too :o ! What must I do with them and what do the MOD with the game ??? :hmmm:

Please Fader_Berg, can you clearify us ? :D

Best regards,
Magic

[Fader_Berg]

If the range estimation fix is enabled in the config file, the range estimations done by the watch- and weapons officers will suffer in presicion depending on three variables. Their qualification, experience and their endurance.

An unqualified, exhausted and/or unexperienced officer will more likely make errors in hes estimations.

Unzip the downloaded file and copy the two files (patSH3r.act & patSH3r.cfg) to the directory where your SH3 installations resides. Open the patSH3r.cfg-file (with notepad) and change the value for range_estimation from off to on if you want to enable this feature.

When you've done that, the changes will apply the next time you start the game.

[Magic1111]

If the range estimation fix is enabled in the config file, the range estimations done by the watch- and weapons officers will suffer in presicion depending on three variables. Their qualification, experience and their endurance.

An unqualified, exhausted and/or unexperienced officer will more likely make errors in hes estimations.

Unzip the downloaded file and copy the two files (patSH3r.act & patSH3r.cfg) to the directory where your SH3 installations resides. Open the patSH3r.cfg-file (with notepad) and change the value for range_estimation from off to on if you want to enable this feature.

When you've done that, the changes will apply the next time you start the game.

Hi !

Aaaah, okay, now I understand !!! :yeah:

Can I do this with the other fixes from h.sie too (I use his V15D Patch) ?

I mean, I want for example, that the persiscope don´t move down automatically. Is this with your MOD possible ?

Is this then the right entry in your .cfg File ? :hmmm:
hsie_periscope off

Best regards,
Magic

[Fader_Berg]

I mean, I want for example, that the persiscope don´t move down automatically. Is this with your MOD possible ?

Is this then the right entry in your .cfg File ? :hmmm:
hsie_periscope off


Yes. If you have 'manage_hsie_fixes' enabled.

[NGT]

Thank you very much for your work.:up:

However, I have a couple of questions for you:

1. How much erroneus can be an estimation -maximum %- and how much exact can be in the best case -1, 10, 100 meters precision-?

2. I can see in your download server: sh3rr-patch.tar.bz2 with the remark:

SH3 Refresh Rate Patch - removes SH3's 50Hz refresh rate request at startup

If I apply that, what (good) will happen exactly?

Thank you again for sharing your work with us. :yeah:

:salute:

[h.sie]

Congratulations. Not tested yet, but it seems you finally got it to work and it could make peoples life easier.

Could you provide me the information (source code) how you got the crew qualification, endurance and so on, because I'll also need these parameters for a future fix (crash dive fails depending on crew qualification)?

Thanks,
h.sie

[Fader_Berg]

1. How much erroneus can be an estimation -maximum %- and how much exact can be in the best case -1, 10, 100 meters precision-?
At best (all times) = ±50m.
Worst:
< 2000: ±100m
2000 - 4000: ±200m
4000 - 9000: ±500m
9000 - 12000: ±1000m
> 12000: ±2000m
2. I can see in your download server: sh3rr-patch.tar.bz2 with the remark:

SH3 Refresh Rate Patch - removes SH3's 50Hz refresh rate request at startup

If I apply that, what (good) will happen exactly?
It's only ment for linux-users having problems to run SH3 under wine in fullscreen.

[NGT]

Thank you very much for answering.

I wait with big interest your next "deep-tweak".

:salute:

[Volk2]

A great idea and fix, thanks!

[Pisces]

I suggest you add the link to h.sie's "Realistic Repair- and Flooding Times (and more!)" thread:

http://www.subsim.com/radioroom/showthread.php?t=174225

Since this does some hacking of the Sh3.exe. (as far as I've read not definitively, but only at runtime) I'm sure alot of people like to know the details about it before they apply it.

[Fader_Berg]

I suggest you add the link to h.sie's "Realistic Repair- and Flooding Times (and more!)" thread:

http://www.subsim.com/radioroom/showthread.php?t=174225

Since this does some hacking of the Sh3.exe. (as far as I've read not definitively, but only at runtime) I'm sure alot of people like to know the details about it before they apply it.

Good points...

[Magic1111]

Yes. If you have 'manage_hsie_fixes' enabled.

Thanks for Reply !

Sorry for my further dumb question, but can you please tell me whether these are the right entries is for my wish with the periscope:
This now looks like my File:


# patSH3r config
# h.sie fixes
#
# If you run a sh3.exe that have been patched by h.sie's V15D patch, you can
# enable and disable those fixes here. Uncomment these lines below.
#
#manage_hsie_fixes yes
#hsie_repair_time on; Repear time fix
#hsie_wo_estimation on; WO range estimation inaccuracy fix
#hsie_wp_estimation on; WP range estimation inaccuracy fix
#hsie_co2 on; CO2 calculation / dive time fix
#hsie_snorkel on; Snorkel speed fix
#hsie_periscope on; Periscope speed fix
#hsie_hydrophone on; Hydrophone fix
# range_estimatmation
#
# This patch gives more realistic range estimates by the WO and WP. The result
# is influenced by their qualification (watch/helms), experience and endurance.
# (Will overide V15D WO & WP estimation fixes if enabled)
#
# This patch is based on the range estimation patch by h.sie (thanks).
#
range_estimation off
manage_hsie_fixes yes
hsie_periscope off


Is this so correct ? Or must the File looks like this:

# patSH3r config
# h.sie fixes
#
# If you run a sh3.exe that have been patched by h.sie's V15D patch, you can
# enable and disable those fixes here. Uncomment these lines below.
#
manage_hsie_fixes yes
#hsie_repair_time on; Repear time fix
#hsie_wo_estimation on; WO range estimation inaccuracy fix
#hsie_wp_estimation on; WP range estimation inaccuracy fix
#hsie_co2 on; CO2 calculation / dive time fix
#hsie_snorkel on; Snorkel speed fix
hsie_periscope off; Periscope speed fix
#hsie_hydrophone on; Hydrophone fix
# range_estimatmation
#
# This patch gives more realistic range estimates by the WO and WP. The result
# is influenced by their qualification (watch/helms), experience and endurance.
# (Will overide V15D WO & WP estimation fixes if enabled)
#
# This patch is based on the range estimation patch by h.sie (thanks).
#
range_estimation off

The difference between the both Variants is, in the first version I added new entries below, just in the second variant I only removed the # and change from "on" to "off"!

What is now correct ? :oops:

Thank you very much for help,

Magic:salute:

[Fader_Berg]

They are both right.

[Magic1111]

They are both right.

Okay, I understand, there are two ways to edit the file, and both are right ! :yeah:´

Thank you very much for your excellent work ! :up:

Best regards,
Magic:salute:

[Magic1111]

Short question: Can I enable the MOD (copying into SH3 Directory) during Mid-Patrol ? Or after Patrol when I´m beeing back in port ?

Best regards,
Magic

[Fader_Berg]

You can do it whenever you like. It shouldn't matter.

[Magic1111]

You can do it whenever you like. It shouldn't matter.

Many thanks !!!! Now everything is clear ! :up:

Best regards,
Magic:salute:

[Hitman]

Sorry but I think I don't yet completely understand this excellent mod: Does it work without h.sie's patches? Even if only for some minor functions? Or does it need to work on a h.sie's fixed exe? :06:

[Fader_Berg]

Sorry but I think I don't yet completely understand this excellent mod: Does it work without h.sie's patches? Even if only for some minor functions? Or does it need to work on a h.sie's fixed exe? :06:

Yes, patSH3r is a standalone project and works without a V15D patched exefile. You'll only get the possibility to run the range estimation fix in patSH3r though.

[Hitman]

You'll only get the possibility to run the range estimation fix in patSH3r though.

Now I understand, many thanks :yeah:

[Fader_Berg]

Beta release of next version is getting closer. I've done some changes to the range estimation code to make it further more realistic. Before the changes, the errors where made in large chunks (e.g. +2000, 0 or -2000 for > 12000), now it's made with any one hundred meters in between.

A new feature that will be implemented is crew rotation, which rotates the crew for you. It's done by fatigue but I hope to be able to make it by schedule too. Some coding remains, but I'm planning to have it done by the end of this week. No promises though...

I've added a poll to decide what to do next. Make yourself heard...

---

Make the crew sensible to distress and discontent
While being locked up in a sub hundreds of meters below the surface and depth charges detonates around it. The crew are under such massive psychological pressure that it affects their endurance and morale.
Also, the miserable conditions the crew was living under for many weeks leaves no one unaffected. Poor sleep, the moisture and limited space plus the constant smell of diesel fumes doesn't come without a price to pay.
Introduce damage/disaster by human factor
Anyone - but most of all exhausted crew - makes mistakes. Sometimes something bad comes out of it...

Pre-heating of G7x torpedoes
The G7-series of torpedoes must be pre-heated or its performance will be reduced, (Personally, I've got a problem with the self-discipline-mod).

[Volk2]

A new feature which will be implemented is crew rotation, which rotates the crew for you. It's done by fatigue but I hope to be able to make it by schedule too.

Are you serious? Wow... I thought it is impossible :yeah:

(The options in poll are too enigmatic for me, so I didn't choose anything).

[Magic1111]

---

Make the crew sensible to distress and discontent
While being locked up in a sub hundreds of meters below the surface and depth charges detonates around it. The crew are under such massive psychological pressure that it affects their endurance and morale.
Also, the miserable conditions the crew was living under for many weeks leaves no one unaffected. Poor sleep, the moisture and limited space plus the constant smell of diesel fumes doesn't come without a price to pay.


I vote for this....:up:

[danzig70]

Great work!

[Fader_Berg]

I'm not that familiar to the SH3 files and their content, but I know some of you are. So I got a question to anyone that can answer it.

I've read the code that do the fatigue calculation and noticed that it take some strange (to me unknown) values into consideration. I guess this is mod-able values from some file/files.

Where (in which file/files and which values - if possible) can you affect the fatigue model?

[Magic1111]

Where (in which file/files and which values - if possible) can you affect the fatigue model?

Look in Basic.cfg and search for Entry [Fatigue Coef] or similar !

Best regards,
Magic

[Hitman]

See if this information can help you, it's from an old post by Der Teddy Bär:

All credit for the following goes to the relevant individuals within Ubisoft and the SHIII Dev Team.

[MEDALS_CREW]
DecreaseFatigueMax=0.1 <== For “Wound Badge” – max level of wearer decrease with 10%
IncreaseMoraleMin=0.1 <== Minimum morale level of wearer increased by 10% - pt U-Boat Badge
HpStep=5 <== Add 5 hit points to the wearer of “U-Boat Front Clasp” - permanent
HpStep1stClass=10 <== Add 10 hit points to the wearer of “Iron Cross 1st Class” - permanent
Experience=1.25 <== Gained experience multiplied by 1.25 for the wearer of “Iron Cross 2nd Class”
StepForMorale=0 <== For “German Cross” and “Knight’s Cross” the morale should be on maximum all the time - this means step 0
StepForFatigue=0 <== For “German Cross” and “Knight’s Cross” the fatigue should be on maximum all the time - this means step 0

The min/max values for morale and fatigue where given accordingly with the rank of the officer/seaman.

========================================

[CREW_0] ;SEAMAN
MoraleMin=0.30 <== minumum that moral can go. Effects ability to perform. Nothing negatively affects moral besides the wounded and dead
MoraleMax=0.60 <== maximum and starting moral
MoraleStep=0.05 <== how quickly moral is recovered when in the rest quarters
FatigueMin=0 <== equals no fatigue i.e. 100% endurance
FatigueMax=0.5 <== maximum % from 100% i.e. in this case 50% is maxed fatigue
FatigueStep=0.2 <== how quickly fatigue is recovered when in the rest quarters
CoefMorale=0.4 <== used in the equations
CoefFatigue=0.2 <== used in the equations
QualEffect=1 <== multiplies base effect of a qualification by #
Hp=10 <== the amount of hit points for a entity i.e Resilience equals life/health. Rank dependent
Wounded=-0.02 <== The % hit to moral when someone gets wounded. Affects only the morale
Dead=-0.05 <== The % hit to moral when someone gets killed. Affects only the morale
SunkShips=0.1 <== the amount of moral added when a ship is sunk
TorpedoHit=0.05 <== ?? Does not appear to have any effect – Does not appear to work.
Experience=0 <== As per the experience for achieving promotion/s

========================================

If the damage in a compartment is > 50% the fatigue is not increased if is < 50% is increased with FatigueSpecificTime. FatigueSpecificTime depends of the U-Boat position - surfaced/underwater.

========================================

[FATIGUE_COEF]
RegularFactor#0 <== One off hit being placed into compartment
RegularFactor#1: <== ???
SpecificFactor#0 <== Continuous loss while within compartment while surfaced
SpecificFactor#1 <== Continuous loss while within compartment while submerged
Badweather <== surfaced and submerged

========================================

[SUBMARINE0]
TimeRecovery01=# <== Corespond with DaysRecovery inside code and this means how much time should be added in base if some subsystems are damaged.

[SUBMARINE2]
…
Comp0=0; Tower Watch
Nb0=5
Subs00=AttackPeriscope
AttackPeriscope=0; E_AttackPeriscope
TimeRecovery00=1

e.g. The AttackPeriscope will take 1 day to be replaced/repaired in base

========================================

The formula used to calculate compartment efficiency is:

- if the compartment is not destroyed or flooded and all the men inside are healthy:
Moral *(10fCoefMorale_per_grad) + fCoefMoral_per_grad*(1-fatigue*(1-CoefFatigue_per_grad)

- if there is a petty officer and has the right qualification for that compartment (e.g. if is a PO with Torpedo man qualification inside the Bow Torpedo Room)
Moral *(10fCoefMorale_per_grad) + fCoefMoral_per_grad*(1-fatigue*(1-CoefFatigue_per_grad)* QualEffect

- if there is a superior officer - the officers have 3 qualifications (similar with petty officer only that is good in other two critical situations than a petty – the officers are your jolly jokers)

========================================

Interval1_0=7.1
Interval2_0=9.6
Interval3_0=19.7

Those intervals are used to establish when the compartment efficiency is:
- 33% - means < 7.1
- > 33% but < 66% - means < 9.6
- Maximum - means > 19.7

[Fader_Berg]

Thank you very much...

[LGN1]

Hi,

I think the posted equation for crew efficiency is wrong. At least, if you set 'fCoefMorale_per_grad' equal to zero the crew efficiency should be zero according to the formula. But that's not what you see in game.

I'm not sure whether it's correct, but I found the following equation for crew efficiency:

http://174.123.69.202/~subsimc/radioroom/showthread.php?t=172432

If someone could confirm or correct this equation I would be happy. Also if someone could fill the missing gaps in the crew efficiency issue.

Cheers, LGN1

PS: Fader_Berg, how do you plan to model the pre-heating of the G7e torpedoes? The way that the player has to give a command and then the speed and range of the G7e increases over a specified time? Do you know how long the pre-heating took in real-life? And how the crew dealt with a situation in which the torpedo was only partially heated (i.e., exact torp. speed unknown)?

[Fader_Berg]

PS: Fader_Berg, how do you plan to model the pre-heating of the G7e torpedoes? The way that the player has to give a command and then the speed and range of the G7e increases over a specified time? Do you know how long the pre-heating took in real-life? And how the crew dealt with a situation in which the torpedo was only partially heated (i.e., exact torp. speed unknown)?

I don't have the answers right now. The three options are merely some ideas to look into. This is things I have come to think about when playing the game and thought would make SH3 a more dynamic game. I can't guarantee to fix any of them, but I sure want to give some of them a try.

Yes, the first thing I thought about was reducing speed and/or range. If there where crew in the torpedo compartment the performance would raise gradually to a maximum.
I don't got all facts though, so I would have to ask people here on this forum for help. What was the loss in performance? How many crew members where needed and how long did it take. Did it increase the risk for malfunction? E.t.c. e.t.c... If no one knows answer, maybe we can make something up.
On the other hand... Maybe the performance loss was so small and out of no game value, that it ain't worth to do anything about it. I don't know. I'll worry about that when/if the time comes.

Thank you

/FB

[Fader_Berg]

Found a bug in previous release where the WP made wrong estimations by 40000 meters or so. New bug-corrected realese 1.0.1 available.
The new range estimation method is included too.

I haven't had as much time I wanted to work on it, but I'm still working with the crew rotation. The logics for this was much harder than I thought. It may take some more days.

Just hang in there...

[Magic1111]

Found a bug in previous release where the WP made wrong estimations by 40000 meters or so. New bug-corrected realese 1.0.1 available.
The new range estimation method is included too.

I haven't had as much time I wanted to work on it, but I'm still working with the crew rotation. The logics for this was much harder than I thought. It may take some more days.

Just hang in there...

Many thanks FB! :up:

Best regards,
Magic:salute:

[Fader_Berg]

Allright... here goes.

Beta release of patSH3r version 1.1...

This release contains the new crew rotation code. It leaves much to be desired, but it is a start.

For now, the rotation will only work for bridge, radio/sonar, helms and the engine compartments. Only for petty officers and sailors...

It comes in two different modes, strict (qualification through SH3 Commander) and float.

More info in the archive... You're welcome to try it out!

Get your beta copy here (http://cjw.tuxxor.net/files/silent_hunter/)
For more information, check head post (http://www.subsim.com/radioroom/showpost.php?p=1571491&postcount=1)

/FB

[Magic1111]

Allright... here goes.

Beta release of patSH3r version 1.1...

This release contains the new crew rotation code. It leaves much to be desired, but it is a start.

For now, the rotation will only work for bridge, radio/sonar, helms and the engine compartments. Only for petty officers and sailors...

It comes in two different modes, strict (qualification through SH3 Commander) and float.

More info in the archive... You're welcome to try it out!

Get your beta copy here (http://cjw.tuxxor.net/files/silent_hunter/)
For more information, check head post (http://www.subsim.com/radioroom/showpost.php?p=1571491&postcount=1)

/FB

Many thanks FB ! :yeah: I´ll try it ! :up:

Best regards,
Magic:salute:

[Hitman]

Thanks for the new release :up:

Again sorry to bother with the same question, but after reading the readme it does not mention H.Sie's fixes. Can I understand that the Range estimation and Crew rotation features work directly on any SH3 exe file, without any need to use H.Sie's work?

A suggestion for the crew rotation:

It would be nice to see the crew rotate in full watch sections, i.e. in the german UBoats there was a "Port" and a "Starbord" watch, which rotated every 4 hours (I think it was 4, NYGM readme has accurate information about this). Even if the player wants to drag a crewmember around for exceptional situations (Attacks), could you make the crew rotate in those 2 watches :up:

[Stiebler]

This is a little embarrassing...

I was unaware of Fader_Berg's new work, and I have delivered to H.sie a general purpose Options Selector so that users can toggle on and off the options that he wants from H.sie's patch updates as they become available. (H.sie needs only to change a text file for each upgrade). This program will be released with H.sie's new patch updates for SH3.exe in a week or two.

Naturally, this Option Selector does not contain any of Fader_Berg's work. Indeed, the Option Selector is intended to work only with a *permanently patched* SH3.exe file, so I suppose it would be valueless with Fader-Berg's work anyway.

But I thought that I'd better announce this, so that no one thinks either H.sie or I are trying to negate Fader_Berg's work.

That is what happens when the same kind of work is done in two different threads...

Stiebler.

[Magic1111]

This is a little embarrassing...

I was unaware of Fader_Berg's new work, and I have delivered to H.sie a general purpose Options Selector so that users can toggle on and off the options that he wants from H.sie's patch updates as they become available. (H.sie needs only to change a text file for each upgrade). This program will be released with H.sie's new patch updates for SH3.exe in a week or two.

Naturally, this Option Selector does not contain any of Fader_Berg's work. Indeed, the Option Selector is intended to work only with a *permanently patched* SH3.exe file, so I suppose it would be valueless with Fader-Berg's work anyway.

But I thought that I'd better announce this, so that no one thinks either H.sie or I are trying to negate Fader_Berg's work.

That is what happens when the same kind of work is done in two different threads...

Stiebler.

...merged both works together...;)

Or is this not possible ? :hmmm:

[Fader_Berg]

Can I understand that the Range estimation and Crew rotation features work directly on any SH3 exe file, without any need to use H.Sie's work?
Yes, or at least most of the V1.4 exe-files. You don't need a V15D (h.sie) patched exe-file if you only intend to use features in patSH3r. In this case a range estimation fix and a beta crew rotation fix.

It would be nice to see the crew rotate in full watch sections, i.e. in the german UBoats there was a "Port" and a "Starbord" watch, which rotated every 4 hours (I think it was 4, NYGM readme has accurate information about this). Even if the player wants to drag a crewmember around for exceptional situations (Attacks), could you make the crew rotate in those 2 watches :up:

I'll put it on the wishlist and we'll see. I'll have to find a way to track in-game time.


This is a little embarrassing...
Don't be embarressed. The h.sie patch switching is not a key feature of patSH3r, as I see it. I just added it because it was so simple and I saw there was a need for it. You're more than welcome to bring your own solution to this and I'll drop mine.

[Fader_Berg]

Crew rotation added. Changes since beta release is that the rotation goes for officers too.

Read more here (http://www.subsim.com/radioroom/showpost.php?p=1571491&postcount=1).

[Hitman]

Excellent!! :yeah:

[Magic1111]

Crew rotation added. Changes since beta release is that the rotation goes for officers too.

Read more here (http://www.subsim.com/radioroom/showpost.php?p=1571491&postcount=1).

Wonderful ! :yeah:

But why do you remove the V15xx patch switching ? :06: I liked to switch any funktionality on/off from h.sie´s MOD !

Best regards,
Magic

[Fader_Berg]

Wonderful ! :yeah:

But why do you remove the V15xx patch switching ? :06: I liked to switch any funktionality on/off from h.sie´s MOD !

Best regards,
Magic

I only had that functionality since there was no other alternatives around. For the V15E patch, Stiebler has made a tool which can be used instead. :up:

[Magic1111]

I only had that functionality since there was no other alternatives around. For the V15E patch, Stiebler has made a tool which can be used instead. :up:

Okay, I understand, but the Tool from stiebler is not avaiable yet...:hmmm:

Until then it would be good, when I can use your solution ! ;)

Is this possible please ?

Best regards,
Magic:salute:

[Fader_Berg]

Is this possible please ?

I'm afraid not. I'm sorry...

[Magic1111]

I'm afraid not. I'm sorry...

Okay, thank you ! No matter.....;)

[Fader_Berg]

I'm currently working on the discontent patch. I would like to get some help in retrieving historical facts on what the typical patrol length is for the different subs. What is the historical longest patrol for each one as well.

[Magic1111]

I'm currently working on the discontent patch. I would like to get some help in retrieving historical facts on what the typical patrol length is for the different subs. What is the historical longest patrol for each one as well.

The longest patrol in WW2 was from Korvettenkapitän Eitel-Friedrich Kentrat with U-196 (13.03.1943 to 23.10.1943 = 225 days). Read here:

http://www.uboat.net/men/kentrat.htm

But the typical length with an Typ VII Boat was 4-5 weeks in average !

Best regards,
Magic:salute: