Underwater range and endurance

[Sniper297]

I know there's been discussion about the S boats submerged range and recharge time, but I noticed the range is a problem for all the fleet boats as well.

All the data I can find indicates all US fleet boats from Porpoise to Balao, and the U-boats from type VII on, list endurance as 48 hours at 2 knots. So 96 miles in 48 hours before the batteries are dead.

Not getting that here, at 2 knots the battery is down to 50% after 14 hours, down to 10% after 26 hours. Total range about 50-55 miles.

So I started tinkering with the files;

\Data\Submarine\NSS_Gato\NSS_Gato.cfg

and

\Data\Submarine\NSS_Gato\NSS_Gato.sim

CFG is pretty simple so the surfaced and submerged speed percentages use the same datablock;

[Unit]
ClassName=SSGato
3DModelFileName=data/Submarine/NSS_Gato/NSS_Gato
HumanPlayable=YES
Interior=data/Interior/NSS_Gato/NSS_Gato
UnitType=200
MaxSpeed=21
MaxSpeedSubmerged=9
Length=95
Width=8.3
RenownAwarded=130


[EngineProperties]
AllStop=0.00
AheadSlow=0.40
AheadOneThird=0.57
AheadStandard=0.80
AheadFull=0.94
AheadFlank=1.00
BackSlow=-0.26
BackStandard=-0.40
BackFull=-0.53
BackEmergency=-0.66

40% of 9 knots is 3.6, so you have to switch to the knots dial to manually set 2 knots for the cruise test.

In the SIM file;

11:unit_submarine

Under the ranges\submerged it's;

miles=96
knots=2

Which is the correct values, but starting a career with a brand new sub diving to 100 feet and cruising at 2 knots I don't GET 96 miles, I get half that.

So I added more to the range including ridiculous numbers like miles=2500 but still don't get anywhere near 96 miles at 2 knots. Did the programmers make a m!$Take converting from metric hectares to nautical miles, or is there another file I'm missing that affects submerged range and endurance?

[Sniper297]

Okay, this is ridiculous. Under ranges/submerged it says miles=96, note underneath specifically says "Maximum range in miles". By all that's holy changing that number to 960 should give it 10 times the range, but it changes nothing - still down to 50% battery after 12 hours and 24 miles, down to 10% after 22 hours and 44 miles. The only thing that number ACTUALLY affects is the recharge time - the higher the number the longer it takes to recharge the batteries! Apparently that number is not consulted at all while discharging the batteries, only when charging, so the screwy thing is programmed to look at that number after you surface to calculate how many miles you ran while discharging the battery to the current level, then uses some kind of bizarre formula to decide how many hours (days!) it should take to recharge according to the number of imaginary miles you ran.

I see now why this was never fixed, some of these labels are a flaming lie. :down:

[ETR3(SS)]

Yeah, quite a few of us figured that out a while ago. Welcome to the club though! :yeah:

[Sniper297]

Thanks, does the club have a secret handshake or will a salute do? :salute:

I'm a glutton for punishment (and there's nothing on TV) so I went back to the unmodified copy to look at the numbers.

S-18 has range 100 miles speed 5
Porpoise has range 72 miles speed 2
All the rest have 96 miles speed 2.

Test I ran submerged to 100 feet while stationary, then ran ahead 1/3rd until the time acceleration went to 1 with the "battery down to 10%" warning. All the boats went about 40 miles, some at 3 knots some at 4 (the percentage of full speed in the CFG files can be changed so any boat does 2 knots submerged, but that also affects surface speed and doesn't seem to make any actual difference in the submerged range - ahead slow is ahead slow). Stop and surface, without moving, time the recharge rate from 10% to 100% without moving (so all the engine power goes to the batteries instead of a percentage to propulsion).

S-18 - 57 hours.
Porpoise - 2 hours 15 minutes.
All other fleet boats 2 hours even.

The rate for the fleet boats is way too fast, should take 6-8 hours. Sugar boat, as has been discussed before, is glacial.

So what happens if I change the numbers in the S-18 from 100 miles 5 knots to 96 miles 2 knots? Nothing to the range, but the recharge from 10% to 100& takes 9 1/2 hours. :-?

Methinks a programmer somewhere labeled something wrong, because the submerged range value has zip point diddly squat to do with the submerged range. But those looking to improve the recharge time on the sugar boats without affecting anything else might want to take a look at that data.

[TorpX]

Test I ran submerged to 100 feet while stationary, then ran ahead 1/3rd until the time acceleration went to 1 with the "battery down to 10%" warning. All the boats went about 40 miles....

I have seen the same thing with my tests. I didn't bother with all the sub classes; after getting nowhere with the S-class and Porpoise class, I figured I was wasting my time.


As far as why all this doesn't work, I have no idea. It doesn't make sense to me. I thought perhaps there was a hard coded limit according to what U-boat performance was, but you said they had similar endurance, so that can't be it. While the game ignores higher numbers, it is possible to reduce sub. range.

The only thing I have to add, is that the recharge times are also a function of the eng power and E eng power. The relationship didn't seem to be linear, however, and I didn't really try to pin it down. Messing with those, would screw up propulsion, and I had no intention of jacking up everything else, to improvise a fix for the batteries.

You would think they would have fixed this sort of thing, before getting to version 1.5 of the game.

[Sniper297]

Yeah, the one experiment I made years ago with the S class diesel horsepower worked, the batteries recharged in a reasonable time. It didn't change the top speed at all, but it changed the acceleration characteristics - IIRC from a dead stop to 12 knots took about a minute without the hack, 10 seconds with the hack. I'm wondering if SKWAS misread what did what to who (and who paid the bail if anyone got arrested) when he was programming S3D. Or possibly the original programmer of the subroutine put a comment in the wrong place.

[Sniper297]

Fun being senile, I was off in several places. It was about one year ago - this is 2014 or 2041? Never mind. Anyway it went 0-12 about 40 seconds in stock, 5 seconds with the horsepower hack, and only cut the charging time in half.

http://www.subsim.com/radioroom/showthread.php?t=200773&page=3

Since the range miles and speed numbers don't seem to have any effect on anything else, that's probably a better way to get close to realistic recharge times.

If we could find the recharge times, possibly THAT data would actually have nothing to do with recharge times but extend the range. :shifty:

[Sailor Steve]

Don't forget that S-boats weren't a part of the original program. They were added at the last minute when potential players insisted, and people pointed out then that they weren't completed properly. Whether they can be properly fixed is a question no one has been able to answer yet.

[Sniper297]

Meantime try the improper fix and see what you think - change the numbers in the S boat SIM file to match the fleet boats, see if it affects anything other than the recharge time.

[TorpX]

Don't forget that S-boats weren't a part of the original program. They were added at the last minute when potential players insisted, and people pointed out then that they weren't completed properly. Whether they can be properly fixed is a question no one has been able to answer yet.

The battery problem seems to go across the board. I couldn't get the Porpoise batteries to proper spec, either.





I was wondering if S3D was somehow malfunctioning (not actually putting in the values we enter), but I guess that is unlikely.

[TG626]

I don't know much about the inner workings of these files, but I do know that as time went by in the world of flight simulator, there were variables that became ineffective. They were vestigal left over a from earlier versions that while they would appear in the config files of later versions, were ignored.

Perhaps that's what is going on here?

[Sniper297]

Hard to tell, SH4 was essentially SH3 version 2 with a few changes for the Pacific war. There's probably a few hundred megs of SH3 u-boat files that aren't used at all but were never removed because the programmers either didn't have time or were unsure which files weren't used.

[Sniper297]

Testing with just the Sargo, I copied my original NSS_Sargo.sim file in to run some tests, original numbers;

Miles=96
Knots=2

I ran the test 10 times because the second run I got a recharge time from 10% to 100% of 5 minutes! :huh: (Honest Chief not a drop. Unless you count rum. :arrgh!: ) The rest were consistent, about 50 miles range and a 3 hour 15 minute recharge time. So;

Miles=96
Knots=2
Actual distance 50 miles
Recharge time 3:15

On to the hacks;

Miles=100
Knots=9
Actual distance 63 miles
Recharge time 11:30

Miles=6
Knots=50
Actual distance 63 miles
Recharge time 48 hours

Miles=1
Knots=50
Actual distance 63 miles
Recharge time 9 hours

Miles=0.5
Knots=90
Actual distance 63 miles
Recharge time 20 hours

Miles=1
Knots=30
Actual distance 59 miles
Recharge time 2 hours

Dunno what to make of all that, it seems to have some kind of digital effect on the range - it's either 49 to 50 miles or 59 to 63 miles, change either number and the recharge time changes a lot, the range changes between one of two values. I ran that last test three times to confirm it was actually 59 miles rather than 63, and was extra careful with the distance measurement. Not sure if 0.5 is actually accepted, possibly it just reads it as 1, but since the miles and knots appear to be an integrated system it's hard to tell.

[Sniper297]

Miles=1
Knots=45
Actual distance 63 miles
Recharge time 6 hours

That's as close as I can get to reality for the Sargo right now, about 22 hours at 3 knots, about 63 miles range before battery down to 10%. The game apparently doesn't factor in number of engines on charge, because stopped dead for six hours (drifting with all 4 engines on charge) or cruising ahead standard for six hours makes no difference to the recharge time.

I can't remember where I saw what numbers, but it was something like 1 hour charge = 4 hours (or maybe it was six) submerged at slow speed. That may have been for the type VII U-boat, data on the Gato I read indicates 36 hours at 2 1/2 knots rather than 48 hours at 2 knots (IIRC that was the figure for the type VII) but the difference is only six miles, 90 miles for US fleet boat versus 96 miles for Das Boot. Don't really matter since whatever I do I can't get near 90 miles or 36 hours at present.

[TG626]

Since we know what it does with 96 miles and 2 knots, I wonder, what does it do with 2 miles and 96 knots?

[ETR3(SS)]

The problem with the recharge times and endurance has to do with the speed you travel at. I don't recall the exact speed offhand but traveling at less than that speed will drain the batteries faster than if you were traveling faster than speed X. Adjusting the range at speed endurance typically results is longer recharge times. In short, you're chasing a ghost. The problem is in a part of the game that we don't have access to.

[Sniper297]

"...what does it do with 2 miles and 96 knots?"

Something similar to 0.5 miles and 90 knots, about 62-63 miles and about 20-30 hours recharge time.

ETR3, I did try the speed control dial, set 1 knot, 2 knots, 4 knots, all result in less range than the default 3 knots I get with ahead 1/3rd on the standard engine telegraph control.

Curious, I was an AX which is also an electronics rate, but the BEEP school at NAS Memphis was overcrowded so the sent a bunch of us to BEEP at SSC/NTC San Diego. Did you go to BEEP there, and where was your A school?

[ETR3(SS)]

Not sure what BEEP is offhand, but I was a striker and struck radio after trying for STS which was a waste of time. I didn't go to A school but it would've been back in Groton, CT with the rest of the A schools except for MT and nuc. C school would've been in Bangor, WA for the Trident Radio Room setup. Think the pipeline was about a year/ year and a half.

[Sniper297]

BEEP = Basic Electricity and Electronics Preparation. When I was active there were two, one at NTC San Diego for all the blackshoes and the other at NAS Memphis for airdales. Most of those bases are closed these days, and of course this;

https://scontent-b-iad.xx.fbcdn.net/hphotos-ash3/t1/q71/s720x720/1798536_689195187791431_918332513_n.jpg

Was retired long ago, replaced by the SH-60.

[ETR3(SS)]

Ah ok. We had SECF which was a common intro for all the "T" rates and then you would branch off from there to your specific rate. SH-3 right? For all the training we did for ASW assets helos never figured prominently into it. P-3's on the other hand was drilled into us.

[Sniper297]

Yep, the Orion crews used to call our Sea Kings "Winnebagos", but I didn't take offense since they were right - I got a few rides in P-3s and it's like comparing a Volkswagen Beetle to a Rolls Royce limo. Smooth ride, no vibration, lots of room inside. The standard joke was that a helicopter was 1000 mismatched parts flying in close formation around an oil leak while waiting for metal fatigue to set in.
But then again, a P-3 can't hover or land on a ship. :salute:

Forgot some other tests, working on those when I'm not tearing my hair out trying to figure out the texture mapping on these blasted subs. All Stop, Ahead 1/3rd, Ahead 2/3rds, Ahead Standard all have the same recharge rate, about 6 hours. Ahead Full takes 11 hours, Ahead Flank 22 hours. Discharge is keyed to speed rather than power, running at Ahead Flank, diving, then going to All Stop the battery continues to drain while the sub is coasting. 9 knots submerged you get 10 miles in a little over an hour before the battery drops to 10%, and the speed is down to 4 knots.

[Sniper297]

Well, after modding a Sargo to run at a max of 12 knots submerged I found that flank speed wasn't draining the battery nearly as fast as I thought it should, and running all ahead standard actually drained the battery faster than flank and decreased the range. Fiddled with the numbers again;

miles = 2
knots = 25

Then ran some tests;

5 1/2 hour recharge from 10%

2 knots (1/3rd)
70 miles

5 knots (2/3rd)
37 miles

8 knots (Standard)
16 miles

10 knots (Full)
51 miles

12 knots (Flank)
47 miles

The first three make perfect sense, increase from 2 to 5 knots cuts the range almost in half, increase to 8 knots less than a quarter, but then 10 knots INCREASES the range, and flank is better than 2/3rds. There must be other files and/or data factored in here, horsepower and/or drag possibly.

[TorpX]

I can't say just why you would get these kind of wonky results, but there is direct relationship between eng_power and drag.

If you have a sub with a eng_power of 1000 and a max speed of 10 there is a certain drag force at 10 knots. If you increase the eng_power to 2000, the drag will be greater. If you decrease it to 500, the drag goes down. There is no useable variable for drag. IOW, the game mechanics presume the vessel can reach the max speed specified, with the power specified, and adjusts the drag forces to fit.

The only other thing I can think of that might cause the odd results, is the Is_DieselElectric = True. If you changed that, it might mess things up.

I never tried making arbitrary changes to the surface eng_power, but the ratio between the surface and submerged eng_power values might be involved here.

[Sniper297]

One interesting item, the CFG file;

[Unit]
ClassName=SSSargo
3DModelFileName=data/Submarine/NSS_Sargo/NSS_Sargo
HumanPlayable=YES
Interior=data/Interior/NSS_Salmon/NSS_Salmon
UnitType=200
MaxSpeed=2
MaxSpeedSubmerged=1
Length=94.6404
Width=8.1788
RenownAwarded=130

The percentages at the bottom;

[EngineProperties]
AllStop=0.00
AheadSlow=0.20
AheadOneThird=0.40
AheadStandard=0.62
AheadFull=0.85
AheadFlank=1.00
BackSlow=-0.26
BackStandard=-0.40
BackFull=-0.53
BackEmergency=-0.66

Are applied to both surfaced and submerged speeds, but the max speeds at the top are not used in game - those come only from the SIM file, change the speeds in the CFG to whatever and it has no effect.

In the sim file I have;

Propulsion
Max speed = 25
Max force = 0.0
eng power = 6140
eng rpm = 280

E propulsion
Max speed = 12
eng power = 2660
eng rpm = 270

Power and RPM are default, the only thing I changed was the max speed.

For the submerged range I just now tried;

miles = 4
knots = 15

3 1/2 hour recharge from 10%

2 knots
68 miles

5 knots
34 miles

7 knots
20 miles

10 knots
34 miles

12 knots
30 miles

Really odd that whatever you do has more effect on the recharge time than anything else, and why the range for 5 knots and 10 knots are the same is completely baffling.

Only drag I can find is up/down and left/right, no idea what that applies to - induced drag fore and aft will increase with speed and would not drop off except with a planing hull (or hydrofoil), which certainly doesn't apply to a WWII submarine - especially when submerged. But the increase in range from Standard to Full speed seems to be more or less consistent.

[Sniper297]

Gets more bizarre by the minute. Restored the original file;

miles=96
knots=2

Then started playing with the e propulsion;

eng power = 2740
eng rpm = 270

Increase either one and it reduces the range, decrease and it increases the range;

eng power = 740
eng rpm = 70

That results in 130 miles at 2 knots and recharge from 10% in one hour. What I'm shooting for here is about 90-100 miles at 2 knots and 6 to 8 hours recharge time from 10%, but near as I can tell there's no way to affect the range without also affecting the recharge time.