Loss of fuel efficiancy!?!
 

After departing from Pearl, steaming to Midway, refueling, departing for some missions over at Honshu, killing everything in site I have 60% fuel left and im 200 nm east of tokyo. I try to sail back to midway with 60% fuel and I run out of fuel before I get there! I used the same cruising speed of 9.5 kts that i used to get to japan but i cant make it back and I had more than half my fuel left! I have no hull damage and nothing is broken (or was broken for that matter) Please help!

Fade

Do the dials still register fuel in the tanks or are the tanks dry? If there dry you may need to lower to crusing speed a touch to try and get some extra range.

The tanks are dry. I have tried making the cruise at 9.5kts and 9 kts and both times I am still 1000nm away when i run out of fuel. I am attempting a third try and am going to see if i can turn off battery recharging

Never dive when trying for fuel economy. Diving means your wasting fuel to recharge the batteries, and if auto recharge is on your not getting fuel efficiency. Thats what your problem is.

Well it looks like the third time is the charm. For some unknown reason for the second half of this cruise I have to turn the "recharge batteries" button off every time I surface dispite never being damaged this cruise and having 100% battery charge.

My biggest regret is an entire night (I dont get nearly enough) wasted trying to sail accross the pacific... real life is a bitch, i want to play computer games :(

Uh use time compression. Press the + or - keys on the number pad to increase/decrease the time compression amount. And as I said when your charging your batteries you use fuel, so you need to take that in to account on fuel economy. If you dont like the fuel/battery limits simply untick them in gameplay options.

I will try to make this clear while trying to not be a jerk. I understand how to play this game, I play at or near 100% realism. I understand all the finer points of fuel management and battery reacharge. I also understand how to use TC but with the constant planes flying over and framerate limitations due to my computer (8000x is not any faster than 1500x for me) coupled with the fact that I cruise at 9.5 kts, three full trips accross the pacific takes up a very large chunk of my night.

In this particular case I believe a glitch is causing extra engines to be run to charge my batteries at surface even though i already have 100% charge and I NEVER incured damage to my sub, let alone batteries. This has cropped up only once for me in all my in game time.

I believe my problem was outside of the normal scope of fuel consumption/ battery recharge

Thank you for your time and help

Do you also understand that when you dive you can go to all stop...not drain your batteries...and therefore not waste fuel recharging when you surface and resume course ? Do you understand that battery recharge needs to be turned off eveytime you surface? Do you understand that repaired damaged batteries will not always recharge 100% and continue to recharge,thus waste fuel, until you turn off recharge?

If you have trouble making it from Japan to Midway with a 60% fuel range remaining then there is something definitely wrong with your ship handling. I do it rountinely at Ahead Full...even Flank at times ...forget 9 knots...:nope:..I save that for patrols when I'm down to 20-30% and need to get back to Midway. Sometimes I have to head south to refuel before I RTB via Midway or Johnson's Atoll.

Also this....LOL...3 trips across takes up a huge chunk of my week...if you are trying to play a full patrol in a single session then...no wonder....

That, in fact, is why my latest career is Asiatic fleet. I got tired of spending 1 of my 2-3 play sessions per week in transit. Now, I still spend 1 play session in transit, but that's because I'm transiting through a target-rich environment. Not 2000+ nm of empty ocean.

I posted a reply after reading only the first post, so I thought you'd suffered some battery damage somewhere along the way. It's acting as if you did. So, you're going to have to manually turn it off every time for the duration of the patrol. It'll be fixed when you get back to your home port.

As Quillan said

Did you recieve any damage and then repaired it?

There is a 'bug' where if you recieve damage to the batterys and later they appear to be repaired to 100% yet will only take on some percentage of full charge. Lets say 90%.

This causes your battery charging system to run continusually wreaking havic with your 'milage'. To stop this you have to manually select 'normal propulsion' after every time you dive. You can check the battery charge state by hovering the cursor over the 'gauge'.

This is the most likely scenario as fuel leaks are not modeled in the game.


Also when going submerged for whatever reason cut your speed to ahead slow. That way you can run for several hours without totally draining the batterys and therefore taking less time to re-charge.

I had the same problem.
And yes it was a battery thing (recharching up to 99%) and yes manually canceling auto-battery-charge really helped BUT...
it was not always the case. There were some cases were I felt that the problem was weather conditions. Making 10 kts with an opposing storm that lasts days isn't the same as making 10 kts in swimming pool conditions fuelwise, at least in Real Life! :yep: Maybe this is also somehow included in the game engine (which would be a great :up: for the devs, by the way!).
Anyway, I got transfered to Fremantle and as the war progresses (now I'm in Spring '44) you also get some forward refueling posts, much closer to the action!
Life is so much easier when you're winning the war! :lol:

Currents are not modeled in the game.

Im not sure if sea state influences fuel consumption, but Ive sailed in all kinds of sea states and never really noticed a loss in fuel effency.

Perhaps the 'battery bug' can also be applied to the diesels. In as much if one of the diesels is damaged at some point, then repaired, it still will not reach 100% efficency.

Im pretty sure that neither sea state, wind, or currents do not effect fuel consumption in the game.

Well another one of my SH4 theories going out of the window! :rotfl:

I think I'd have to disagree on a technicality. While sea state, wind, and currents may not directly affect fuel consumption, how deep you are in the water does. To set the technical portion of the discussion: Using the bell (Ahead 1/3, 2/3, etc) basically tells your engine crew to maintain a fixed number of RPMs (actually it's run 1, 2, 3, or 4 engines at cruising rpms except for flank which is run all engines flat out). Using the knots annunciator tells your crew to maintain a speed regardless of how many rpms you turn.

Now, if your decks are awash, that takes more work than if they aren't. And this must be modeled because when your decks are awash, ahead 2/3rds isn't as fast as if they aren't. So if the waves are setting your decks awash (generally indicated by your depth to keel indicator bouncing up and down) then it stands to reason that would affect RPMs (and therefore fuel consumption) if set to maintain speed, since it affects speed if set to maintain RPMs.

Decks awash means that you're running on batteries hence the lower speed with the same general engine setting (1/3, 2/3 etc).

Sometimes when sea is really high and you're on the bridge you might instantly find yourself in the control room. High waves have caused you to involuntarily submerge!:yep:

From what I've seen (1.4, no significant boat mods), it sounds like (based on ambient engine noise) that the electrics don't kick in until your Depth to Keel is around 30. So if you're fluctuating between 15 and 25, the electrics never kick in, yet I've noticed my speed reduced.

Decks awash = ~10m =~30ft
Stock 1.4, no mods here as well

While currents may not be modeled in the game, speed reductions due to rough seas are modeled. Getting swamped is not required. Try it once and see: set Ahead Standard when setting out from your port at the beginning of the patrol and see what speed you get with calm seas, then do the same at some point when you have 15 m/s winds; you'll find you're going a knot or two slower.

That implies a fault in the game. Surely having a tail wind should increase your speed, whilst a head wind would reduce it? You imply there is no differentiation in the wind direction's effect on your submarine's speed, thus that is a fault.

I have similar concerns over the 'decks awash' theory. There's a very real chance that only the keel depth is taken into account when calulating surface speed and wave height (also known as wind speed) has nothing to do with it. Unless observations have been taken to the contrary. The only test to confirm that would be to run at x depth with y wind speed for all cases of y and x.