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Old 11-01-07, 06:01 PM   #1
Archive1
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Default Diesel consumption too high in type IXB

It seems to me that the fuel consumption for the type IXB is way too high. Historically R. Hardegen (U123) went 8,918 NM with only 50 NM submerged in second patrol to the US East coast (Op Drumbeat) in 1942. I tried to duplicate this: required at least 50% time submerged, surface speed ahead 1/3rd and arrived at US coast with only enough fuel remaining for 3,000 Km (not, note, 3,000 NM) - no way to get back to Lorient. Should point out that Hardegen did not refuel at sea and ran out of fuel in the approach to Lorient - entered surfaced with E engines.
I cannot comment on the type VIIs.
Any comments on how to revise diesel consumption downward?
Running GWX1.3 by the way.
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Old 11-01-07, 06:13 PM   #2
ref
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Quote:
Originally Posted by Archive1
It seems to me that the fuel consumption for the type IXB is way too high. Historically R. Hardegen (U123) went 8,918 NM with only 50 NM submerged in second patrol to the US East coast (Op Drumbeat) in 1942. I tried to duplicate this: required at least 50% time submerged, surface speed ahead 1/3rd and arrived at US coast with only enough fuel remaining for 3,000 Km (not, note, 3,000 NM) - no way to get back to Lorient. Should point out that Hardegen did not refuel at sea and ran out of fuel in the approach to Lorient - entered surfaced with E engines.
I cannot comment on the type VIIs.
Any comments on how to revise diesel consumption downward?
Running GWX1.3 by the way.
Had you have a lot of wind in the travel? it affects fuel consumption.

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Old 11-01-07, 06:15 PM   #3
von Zelda
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Quote:
Originally Posted by Archive1
I tried to duplicate this: required at least 50% time submerged, surface speed ahead 1/3rd and arrived at US coast with only enough fuel remaining for 3,000 Km
Any comments on how to revise diesel consumption downward?
Surface speed of 1/3 burns more fuel; instead try 8 knots, set manually. Wheather conditions also a factor.

While running submerged uses no fuel, it does require more fuel to recharge batteries. Most, if not all, u-boats ran on the surface in mid Atlantic at the time of Drumbeat.
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Old 11-01-07, 06:39 PM   #4
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Ref:
Nope, mostly quiet seas (Hardegen had terrible weather.)

von Zelda:
If I ask the Navigator to give me an estimate of distance available at present speed, frequently the answer indicates that ahead 1/3 is more efficient than ahead slow...or any manually set speeds. And yes they (UBoots) stayed surfaced most of the time, that's my point I guess. There is no way one can get to the US surfaced at any speed I can find and still have fuel to get back in SHIII...this isn't the only time I've tried it - only the first time I've posted anything on the forum. (Old hand at SH going back to SHI, BTW.)

Maybe no answer, but seems something's not correct.

Thanks for the answers from you both.
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Old 11-01-07, 06:48 PM   #5
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I use 8 Knots manualy set fro best fuel/range in my IXB, this drops to about 6 or 7 in slightly rougher seas. I have been to the Canadia coast after passing through the channel whilst transfering from Willhelmshaven to Lorient. head 1/3 consumes more fuel of course, but even so there should be enough to get there and back. Not sure what it could be.
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Old 11-01-07, 07:01 PM   #6
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Archive1:

I have noticed the same problem and not only with the IXD2 and I have chosen to solve it by slightly adjusting the operational range upwards using the Jonesoft Tweaker

That Kilometre feature in SHIII is something that really annoys me by the way! Distance has always been measure in NM and nothing else
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Old 11-01-07, 09:56 PM   #7
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Quote:
Originally Posted by 3Jane
I use 8 Knots manualy set fro best fuel/range in my IXB, this drops to about 6 or 7 in slightly rougher seas. I have been to the Canadia coast after passing through the channel whilst transfering from Willhelmshaven to Lorient. head 1/3 consumes more fuel of course, but even so there should be enough to get there and back. Not sure what it could be.
I'll try it, although I think I've used most every variation of manual speeds. And if Ahead 1/3 is more 'thirsty' than Ahead Slow why does the Navigator often (frequently) respond to queries about "...distance available at current speed..." by giving greater available distance for 1/3 than for Slow? I used to intuitively believe 'Slow' must be more fuel efficient than '1/3rd', but that does not display as the fact.

[Werewolf] I have noticed the same problem and not only with the IXD2 and I have chosen to solve it by slightly adjusting the operational range upwards using the Jonesoft Tweaker.

I have the MiniTweaker program and have used it (great program!) but am unaware of an operational range adjustment utility...or maybe I just don't know where the code is that needs to be tweaked. Can you provide info on where/what it is?

Thanks to you both for the reply.
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Old 11-02-07, 05:06 AM   #8
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Yeah it's a great program, all of the Jonesoft programs are

The file you need is the NSS_Uboat9b_sim.txt, then you open the "Categories" menu and choose "Diesel Propulsion", then you'll see a line called "milesSurfaced" that's the one, just alter it to another value
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