SUBSIM Radio Room Forums



SUBSIM: The Web's #1 resource for all submarine & naval simulations since 1997

Go Back   SUBSIM Radio Room Forums > Silent Hunter 3 - 4 - 5 > Silent Hunter III
Forget password? Reset here

Reply
 
Thread Tools Display Modes
Old 01-06-07, 04:07 PM   #1
Ducimus
Rear Admiral
 
Ducimus's Avatar
 
Join Date: May 2005
Posts: 12,987
Downloads: 67
Uploads: 2


Default Good at math? I have a problem for you.

It's all about FUEL! Im sure this will draw Letum like a magnent


One of the biggist mysteries to me, is exactly how much fuel is in a uboat, and.. the rate of consumption. But to boil the fat away, ive always wondered exactly how much fuel a trip to X destination would consume.


Awhile ago, i made this observation. Its a bit from Donitz's war diary:
(Picture linked cause it skews the page)
http://www.ducimus.net/sh3/BDU_on_Fuel.JPG

From this i make 4 assumptions:
1.) He's talking about Nautical Miles

2.) CBM means, Cubic Meters

3.) Hes noting how much fuel a uboat will have after making the trip To that area. Not how much they have to operate in that area, with the to and from trip already accounted for. (or do i have this backwards?)

4.) These are ballpark figures, not exact ones. We have no idea under what conditions or assumptions (if any) he made these calculations.


Now, according to this page:

http://www.uboataces.com/uboat-type-ix.shtml
A....
IXB has 165 Tons of fuel
IXC has 208 tons of fuel
IXC/40 has 214 tons of fuel.

So my thought is, to take BDU's estimate of how much fuel is remaining in the tanks after making a trip to X locaton, convert it to metric tons, and then convert that to a percentage against its total capcity?

What im having trouble with, is the density of the fuel, and finding an applicable formula to apply it too. And, i have to admit, mathimatics was never my most keen subject.
Ducimus is offline   Reply With Quote
Old 01-06-07, 04:10 PM   #2
azn_132
Grey Wolf
 
Join Date: Apr 2005
Posts: 950
Downloads: 0
Uploads: 0
Default

Quote:
Originally Posted by Ducimus
It's all about FUEL! Im sure this will draw Letum like a magnent


One of the biggist mysteries to me, is exactly how much fuel is in a uboat, and.. the rate of consumption. But to boil the fat away, ive always wondered exactly how much fuel a trip to X destination would consume.


Awhile ago, i made this observation. Its a bit from Donitz's war diary:
(Picture linked cause it skews the page)
http://www.ducimus.net/sh3/BDU_on_Fuel.JPG

From this i make 4 assumptions:
1.) He's talking about Nautical Miles

2.) CBM means, Cubic Meters

3.) Hes noting how much fuel a uboat will have after making the trip To that area. Not how much they have to operate in that area, with the to and from trip already accounted for. (or do i have this backwards?)

4.) These are ballpark figures, not exact ones. We have no idea under what conditions or assumptions (if any) he made these calculations.


Now, according to this page:

http://www.uboataces.com/uboat-type-ix.shtml
A....
IXB has 165 Tons of fuel
IXC has 208 tons of fuel
IXC/40 has 214 tons of fuel.

So my thought is, to take BDU's estimate of how much fuel is remaining in the tanks after making a trip to X locaton, convert it to metric tons, and then convert that to a percentage against its total capcity?

What im having trouble with, is the density of the fuel, and finding an applicable formula to apply it too. And, i have to admit, mathimatics was never my most keen subject.
What? I dont get what this is all about.
azn_132 is offline   Reply With Quote
Old 01-06-07, 04:14 PM   #3
Ducimus
Rear Admiral
 
Ducimus's Avatar
 
Join Date: May 2005
Posts: 12,987
Downloads: 67
Uploads: 2


Default

Quote:
Originally Posted by azn_132
What? I dont get what this is all about.
In a nutshell.

60 CBM is how many ton's?

X number of tons converted from the CBM is how much of the total fuel capcity as a percentage?

edit: and to me the question still remains, is BDU talking about how much fuel is in the tanks after making the trip, or how much fuel the boat has to operate in that area, not counting the fuel used going to and from that area. I think that answer lays in how large or small a percentage the "CBM" is against a boats total fuel capcity
Ducimus is offline   Reply With Quote
Old 01-06-07, 04:20 PM   #4
hyperion2206
Ace of the Deep
 
Join Date: Jul 2006
Location: Cologne, Germany
Posts: 1,227
Downloads: 8
Uploads: 0
Default

I searched the internet and found that for example 140 CBM equals 140000 liters or 36984.087330141 US liquid gallons. Hope that helps.
__________________
Career of Captain Jack Shaftoe:


hyperion2206 is offline   Reply With Quote
Old 01-06-07, 04:21 PM   #5
nightdagger
Officer
 
Join Date: Nov 2006
Location: Houston, TX
Posts: 243
Downloads: 0
Uploads: 0
Default

Density = Mass / Volume.

Find the density and either the mass (tons) or volume (cubic meters) and you can convert.
__________________
nightdagger is offline   Reply With Quote
Old 01-06-07, 04:31 PM   #6
bigboywooly
Rear Admiral
 
Join Date: Apr 2006
Location: Swindon, England
Posts: 10,151
Downloads: 35
Uploads: 0
Default

From the way it reads
The Uboats will have that much fuel left to operate IN the region

In other words journey to and from removed from equation and thats whats left
Of course it has to be guess work figures as weather/engine condition and usage and evasive tactics employed on either route would all impact on fuel reserves

And I dont think they had at that time actually ran a boat to those locations
And of course you dont know whether that includes refuelling
__________________


My mediafire page http://www.mediafire.com/?11eoq19bq9r41
bigboywooly is offline   Reply With Quote
Old 01-06-07, 04:51 PM   #7
hyperion2206
Ace of the Deep
 
Join Date: Jul 2006
Location: Cologne, Germany
Posts: 1,227
Downloads: 8
Uploads: 0
Default

If you look at this page Sydney seems to be the nearest location, therefore they U-Boats must be stationed in Penang, right? But why does a IXC only have 140 cbm of fuel left (I mean it's only 2200 miles). So I guess 140cbm is the amount of fuel that can be "wasted" in the operation area, when 140cbm are used it has to return.:hmm: But that's just crappy guesswork.
__________________
Career of Captain Jack Shaftoe:


hyperion2206 is offline   Reply With Quote
Old 01-06-07, 06:27 PM   #8
Ducimus
Rear Admiral
 
Ducimus's Avatar
 
Join Date: May 2005
Posts: 12,987
Downloads: 67
Uploads: 2


Default

Quote:
Originally Posted by hyperion2206
If you look at this page Sydney seems to be the nearest location, therefore they U-Boats must be stationed in Penang, right?
He meant the OTHER sydney

http://en.wikipedia.org/wiki/Sydney,_Nova_Scotia
Ducimus is offline   Reply With Quote
Old 01-08-07, 02:48 AM   #9
fabel
Shore leave
 
Join Date: Jan 2007
Location: Netherlands
Posts: 70
Downloads: 9
Uploads: 0
Default

Quote:
What im having trouble with, is the density of the fuel, and finding an applicable formula to apply it too. And, i have to admit, mathimatics was never my most keen subject.
I always let my navigator calculate the maximum range at current speed. It's interesting though, one time I got the message 'We're out of diesel fuel, Sir!', but the engines still could ran an additional 200 km. So I think you also got a reserve or something?
__________________
fabel is offline   Reply With Quote
Old 01-08-07, 08:11 AM   #10
Dietrich
Sparky
 
Join Date: Jul 2006
Posts: 152
Downloads: 0
Uploads: 0
Default

[quote=fabel]
Quote:
It's interesting though, one time I got the message 'We're out of diesel fuel, Sir!', but the engines still could ran an additional 200 km. So I think you also got a reserve or something?
If you're really desperate, go to periscope and get another 50+km out of your batteries.
Dietrich is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 01:53 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright © 1995- 2025 Subsim®
"Subsim" is a registered trademark, all rights reserved.