SUBSIM Radio Room Forums - Combat Radius planning (confused)

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Combat Radius planning (confused)

Hello all; been playing SH4 (1.4) for a month now and found this site to be a great resource.

Just began a career on full realism and obviously have to keep fuel consumption in mind.
I did some tests running south out of pearl on the surface in a Gar class, till I got to 50% fuel level (combat radius) got these results:

standard=3000nm (+/- 60nm/1%)
2/3 = 5500nm (+/- 110nm/1%)
1/3 = 7600nm (+/- 152nm/1%)

2nd patrol had me south of Kyushu. Completed mission and headed east to refit at Midway (3350nm away) w/ 57% fuel remaining (presumably +/- 6270nm @ 2/3), set time comp and let it ride. Ended up running out of fuel (and then battery) 30nm from Midway??????

Obliviously running 1/3 &/or partially on batts would save fuel.

I'm just really confused how far off my fuel plan was and would appreciate any insight.

Thx

Combat Radius planning (confused)

Welcome to SUBSIM :-)

See this post-thread:http://www.subsim.com/radioroom/show...47&postcount=3

Quote:

Originally Posted by Cdux (Post 2280304)

2nd patrol had me south of Kyushu. Completed mission and headed east to refit at Midway (3350nm away) w/ 57% fuel remaining (presumably +/- 6270nm @ 2/3), set time comp and let it ride. Ended up running out of fuel (and then battery) 30nm from Midway??????

I don't understand how this would happen, unless you made a mistake in your math, or your procedures. (You must let the boat reach an equilibrium before you have your navigator estimate the max. range, otherwise, his figures will be inaccurate.) Did you charge batteries on the way back? Could you have set the speed higher than you meant to?

In general, it is best to avoid using the battery as far as fuel is concerned. Charging uses up a significant amount.

I follow the same general procedure you do; that is, tabulating the fuel consumption at different speeds, and then computing what I will need as the patrol progresses. It always works for me. However, I, and most others here, play v1.5 of the game, with mods, so there may be oddities in v1.4, that I don't know about.

Well here is an update.
replayed from my save point at patrol station, did 1/3 back to midway. consumption seemed to be the same but was able reach the refit point on battery power after running out of fuel.

while steaming back did a report for a time stamp & got assigned Luzon straight,

so did another save point (an overwrite of the patrol one) at midway & headed SW at 2/3, checked weather every sun rise/set, and marked progress @every 10% drop. made it 2250nm on 50%, 450 every 10th of tank, there and back. only had a 130 mile stretch that was not fair seas or better. every that was still 450nm/10%.

reloaded from save point, exact same #s doing 1/3, reload again & tried standard, again 450nm/10th. Turned around and tried running on batteries & recharging on standard, and got the same damn thing. ????

refitted (on the same game, didn't reload) and headed home to pearl at 2/3s, but after 200nm notice the fuel isn't dropping as fast, I'm still @ 98%.
head her WSW towards Luzon & get 1000nm from 98-88% @ 2/3s, knock it down to 1/3, get 1500nm on the next 10%. Make it all the way there with plenty to spare, (where promptly I got wasted by a destroyer). ????

I doubt bad fuel modeled in this game; not that that would account for the same mpg no matter the speed.

I guess the next test is to re-load, run just outside of midway & turn back in to refit.

I'm not sure I follow the details of your patrols, but you should be aware that the fuel consumption is a function of the engine speed output, not the telegraph setting. Standard for you may be 14 kn., but may be 12 or 16 for someone else, as these settings are modded often. It doesn't matter what you call it, it is the speed for that model of boat that is important.

I've never noticed irrational variations in fuel consumption myself. If you think that is happening, you should be watchful of battery charging, weather, and possibly problems caused by Alt-Tabbing out of the game. This last has been known to cause problems with CO2 buildup, and for me, has caused battery drain problems.