You're welcome. Why did you change your nickname?

Currently looking into the compressed air issue mentioned by Rubini, but after reading this post

http://www.subsim.com/radioroom/showthread.php?t=163651

I must admit that I'm a little bit confused. It will take some time simply to understand what exactly the problem is....

In a nutshell, the main problem is that compressed air does not get used (And exhausted) unless you blow ballast. Changing depths with little speed (At higher speeds the dive planes do the job) would need use of compressed air, but in Sh3 is almost unnoticeable. Also, even if you changed depth upwards with the dive planes, a bit of compressed air should be used, as you would need to empty the ballast tanks a bit to remain buoyant at the new chosen depth. Otherwise you would be too heavy and sink again if you slow down.

While I have absolutely no historical data to back my opinion, I think that the difference might be too excessive. Silent running as proposed by you sends crewmen who were unnecessary for operating the sub to their bunks with the Dräger device (Which is historically correct in some situations). But if they were not necessary, then they were not doing any physical tasks (The ones where more oxygen is consumed) and it is safe to asume that the difference in oxygen consumption will not be that much.

For example, if we take 100% oxygen consumption as base case for a normal situation, and asuming that a man in physical tasks consumes twice as much as resting, and 4x than when sleeping, it would look like this:

-50% Watch crew on tasks: 75% oxygen consumption
-50% Watch-off crew resting or sleeping: 25% oxygen consumption

Total = 100%

Now, on silent running situation you are reducing by half only the consumption of the off-watch crew, and hence:

-50% of crew active on physical duties: 75% oxygen consumption
-50% of crew resting with Drägers: 12,5%

Total = 87,5%

In a more radical situation, where only a barebones crew is active during silent running, it would look like this:

-25% of crew active on physical duties: 37,5%
-75% of crew resting with Drägers: 18,75%

Total = 56,25 %

Well, those are quick numbers, but you get the idea :hmmm:

http://www.subsim.com/radioroom//sho...27&postcount=8

If someone with legal starforce sh3 will be searching for appropriate sh3.exe, please direct him to me.

Hi Hitman,

thank you for the input. The factor of 2,0 regarding CO2 & diving time was only my assumption some days ago, also without deep historical background. Since there was no protest from the people here, I used that factor for the fix, but all factors I used, can easily be changed in the next version V15D and after some deeper research for that topic. I am just a programmer with very limited historical background, and I would be thankful if someone could do some investigation regarding this topic.

Unfortunately, without SDK, I have to restrict on easy-to-fix-solutions. I cannot find out for every crew member if he is currently working or not. So my only chance is to analyse the Silent-Running Status bit, which has only 2 states: Silent-Running ON or OFF. Maybe it's a good idea to assume that the ON state lies between the second and the third (radical) of the three cases you described, which results in an average value of (87% + 56%)/2 = 72%, so that we get a new factor of 1/0,72 = 1,4 instead of 2,0.

One thought (which cannot be assigned 100% to the topic above): In my opinion, it sometimes makes sense to have gameplay-balance in focus instead of pure historical data. As an example, let's say, according to badly implemented physics, the destroyers accelererate too fast. In this case it would not be a good idea to make the Uboats accelerate slowly according to historical values. For good gameplay-balance, they also have to accelerate too fast, so that they get no disadvantage. We should keep this in mind when we are discussing about realism/historical data and so on.

Have a good night.
h.sie

yes that was the idea :up: I know you can only set two states alternatively, I just wanted to point out that in the current choice we have, probably 70% or so would be better.

Okay. But with a factor of 1,4......1,5 we don't achieve the historical maximum diving times, except I raise/extend their default values by a certain correction factor (what I already did for the XXI).

By the way: It would be easy for me to take the crew number into consideration when calculating CO2 cumulation/diving times. But:

1) I have only incomplete historical data regarding standard crew numbers and diving times.

2) Since the sh3.exe differentiates only between 4 main types (II, VII, IX, XXI) we would have to use average values regarding standard_crew_number and max_diving_time_with_standard_crew_number, e.g. for IXB, IXC, IXD2.

3) We must be sure that no additional oxygen supply is loaded for additional crew, because in this case diving times would not depend on crew number.

What we have: Technical requirements for:
-IIA/D: ?? hours with ?? men
-VIIC: 72 hours with 37 men
-IXC: 72 hours with 44 men
-XXI: 150 hours with 50 men

So has anyone information for the Type II??
h.sie

Well, regarding my own experience with stock 1.4, it's not exactly true.
For a very long time of play, I haven't notice anything about compressed air. But a few months ago, I modified some tactics when ordered to patrol along England shore early war.
I travelled underwater very slowly, less than 3 knots, and surfaced every 6 hours, but stayed on surface only the time to get fresh air, only a few minutes, then I looped the cycle.
After some time I noticed that my compressed air slowly decreased. So surfacing, even with some speed, consumes air. But so few that you need a great number of cycles without "resupplying" to notice.

I also discovered that some compressed air is used when hitting "S" in order to surface.

Hi all,

Not sure if its any help to you for your calculations, but i use breathing apparatus at work which hold 1800 litre compressed air cylinders.

Now air consumption is based on 40 liters per min for an average person doing a steady rate of work, which gives 45 mins duration. However when doing hard physical labour i have known this to drop to about 15 -20 mins, with 30 - 35 a more realistic max time.

If resting though 45 - 60 minutes are achievable.

Only problem i have no idea how much air a VIIC would hold :)

but hope this can be of some help.

Out of interest i found this (not mine) similar to what i use

http://www.firetactics.com/scba-uk.pdf


regards

slipper

Thank you, slipper.

This gives us an idea about the difference in oxygen consumption and CO2 production between rest and hard work.

Resting: avg. 52min
Normal work: 45min
Hard work: avg. 32min.

So the factor calculated between resting and hard work is 52/32 = 1,6 which differs only a little bit from the value 1,4 which I calculated from Hitmans information.

So in the next version I'll use a factor of about 1.5 instead of 2.0, that means while in Silent-Running, the CO2 production is about 1.5x lower than in standard situation and diving time is accordingly longer.

h.sie

Hi all,

the data for the XXI I posted is from here:

http://www.uboatarchive.net/DesignSt...ypeXXI-S38.htm

It's a US design study from 1946. Look at the first paragraph on page 3. I guess this is the most accurate information we have at the moment.

The factor between CO2 accumulation with and without silent running is, IMHO, not so crucial (it will always be a quite crude modeling in-game because you don't have higher breathing rates because of fear,...). What is much more important is that an accurate submerged endurance is achieved. What I like about the higher factor is that the player has a larger benefit from using silent running. At the moment there is practically no advantage from switching silent running on.

Concerning the compressed air, I have no idea what to do. At the moment it seems pretty useless (is there anyone who was ever influenced by it in-game?). But how to make it useful or influencing your decisions in a somehow realistic way, I have no idea :06:

Cheers, LGN1

Just found out that it will be very easy to enhance my CO2_and_diving_time_fix by also taking the crew number into consideration.

Example Type VII: Historical Data:
Max. Diving time = 72h (with 37 men on board).

Now lets assume there are 42 men on board.
And let's also assume there is no additional oxygene supply for these 5 men (is this second assumption correct???).
Then 42 men will produce 14% more CO2 than 37 men, so that max. diving time will be reduced about 14%:

72h * (1-0,14) = 62h.

What do you think about that?

Every answer is welcome, but expert/'veteran' answers are very welcome.

Thank you.
h.sie

Hi h.sie,

I like it! I don't know for sure whether the oxygen supply was fixed, but I find it hard to believe that they installed additional supplies according to the crew number. I think that if you have space to install additional supplies when the crew is larger, you also have space to do it when there are less crew members (you have even more space for it). So, why don't install them also for smaller crews? It shouldn't hurt :06:

So, if it's easy I would implement your proposed solution. It sounds reasonable.

Cheers, LGN1

Dett hepp ick me dacht

under attack? hunting or hunted?
 

I believe I read somewhere that the game can alter the game speed while hunting or being hunted. I suggest that such times of high stress might be a time of more use of breathable air. So then you would have four states, perhaps five if damaged.
normal, silent-running, hunting (in contact), being hunted (under attack), and damaged with DC crew working. These are suggested signals that you can get from the game, perhaps. Just a suggestion.