How exactly does fuel work?

[Ducimus]

Inquiring fuel miser's want to know:

1.) THere isnt another "Nasa" type error in the sim files with fuel range is there? My assumption is no, but i have to wonder because the orginal values were (a much lower value then what youd expect) @ 12 knots. For example, (out the hat number) 8000 @ 12 kts instead of say 13,450 @ 10 kts. Of course those 2 extra kts add alot of fuel by themselves. Which leads me to my next question.

2.) Exactly how much fuel is in a boat that can do 13,450 @ 10 kts? Or any variation of that figure thereof? I wish i knew exactly how many cubic meters, tons, gallons, whatever are in the fuel tanks of a boat. WHich brings me to my next question.

3.) Anyone figure out how exactly fuel consumption works? My assumption is its based on RPM, much like noise and E motors. The higher the RPM, the more fuel you burn. RPM's are going to range from 100 to 500. So if you could put a figure on how much fuel you have (see question 2), then how much fuel of that same measurement are you burning at 100 RPMs, or 500 RPMs?


Maybe im making a moutain out of an anthill but every time i plan out a patorl, all of the above nags at me.

All i know for sure is recharging batteries, uses the starboard diesal (regardless if the boat is in motion or not), and it runs at 500 RPMs for as long as it takes to recharge the bats. Usually 3 to 4 hours. Ever wonder how much fuel that burns up? I do, constantly.

[Montbrun]

Good question. My Chief Engineer always tells me I'm out of fuel, when the Navigation Officer tells me I have another 600-800km left, and the Navigation Officer is always right....

[Patboot]

Engineers are historically Scottsmen, and miserly about things.

When a reserve drops to 10% they go into apoplexy, and howl at the Captain that the world will end soon.

'course 10% of 60 tons of diesel will get you a good ways...

Math is left as an exersice for the student.

[don1reed]

The U.Boat Commander's Handbook lists the max fuel of a IXc as 209.2 tons.

edit:

Appendix II: U-Boat Specifications, 1935-1945, Eberhard Rössler's book, THE U-BOAT, lists the IXc/40 at 214 tons.

[VonHelsching]

1.) THere isnt another "Nasa" type error in the sim files with fuel range is there? My assumption is no, but i have to wonder because the orginal values were (a much lower value then what youd expect) @ 12 knots. For example, (out the hat number) 8000 @ 12 kts instead of say 13,450 @ 10 kts. Of course those 2 extra kts add alot of fuel by themselves. Which leads me to my next question.

Probably no. Check one of my last messages in the Nasa Advanced Battery fix thread. I was hoping that Ubi would repeat the Nasa mistake but they didnt. What they did, though, IMHO is that they pulled a real quick n dirty fix about the fuel. I modified the sim file and put 100 miles for range. Did quite a lot of testing. The boats finish their fuel (Fuel Tank Empty, Sir!) and continue to "drift" for IIRC 9 miles for every 100 miles in their fuel tank. This offsets at least partially IIRC for a possible nasa mistake.

.2) Exactly how much fuel is in a boat that can do 13,450 @ 10 kts? Or any variation of that figure thereof? I wish i knew exactly how many cubic meters, tons, gallons, whatever are in the fuel tanks of a boat. WHich brings me to my next question.

3.) Anyone figure out how exactly fuel consumption works? My assumption is its based on RPM, much like noise and E motors. The higher the RPM, the more fuel you burn. RPM's are going to range from 100 to 500. So if you could put a figure on how much fuel you have (see question 2), then how much fuel of that same measurement are you burning at 100 RPMs, or 500 RPMs?

Don't know about 2)

For 3) probably RPM, BUT there are many factors that affect consumption and some of them are probably not modeled (wind, engine fatigue, leaks etc.) Furthermore you cannot measure the distance traveled a) beacuse the navigation model in SH3 is simplified and b) you need a special type of map to do this and I'm not sure if it can be done with many degrees of lattitude. I mean
it might be OK to plot Ireland to NY but not Azores to Freetown with one map.

[U-Bones]

A basic engine will inhale pretty much the same amount of fuel mix for every rev - thus the cylinder rating by volume - be it cubic inch or cc or litre. This is pretty much independant of RPM.

The primary reason lower speeds get better efficiency has to do with the physics of pushing a displacement hull through the water, ie displacing water at varying rates.

Cruize speed is the sweet spot - any time you take it beyond this speed, the energy expense skyrockets.

For sailboats, hullspeed (max speed possible for the hull) is primarily a function of length at waterline, with cruize being somewhat under that. No idea how it was calculated for a sub of that era.

[kptn_kaiserhof]

i got the same qustion only for oxygen: how do i maintain same level of oxygen while suberged and with no shnorkel

is it a cfg or what??

[VonHelsching]

Originally Posted by kptn_kaiserhof

i got the same qustion only for oxygen: how do i maintain same level of oxygen while suberged and with no shnorkel

is it a cfg or what??

You can do it with the realism settings.

[kptn_kaiserhof]

no no no not that way i dont mean realism setings ether

i want my subs air supply to last at least 2 months

beacuse she peformes like a soviet november class sub/k 19 style