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-   -   Best way to cross the pond (https://www.subsim.com/radioroom/showthread.php?t=131509)

bertockamus 02-22-08 11:05 PM

Best way to cross the pond
 
I've just started a GWX 2 career in 1940 with the 2nd and have given up my trusted VII for a IX so I can cross the atlantic. What is the best way to cross and have enough fuel to make the hunt worthwhile?

Do you hit the tanker by Greenland on the way over and the way back? What is the best use of the electric engines to conserve fuel? Is ahead standard the most economical?

Thank you for your advice.

Antiacus 02-22-08 11:42 PM

I've found almost double the endurance at ahead 1/3 vs ahead standard.

Tessa 02-22-08 11:45 PM

Cruising via standard speed is not the most economical way to get the most mileage out of your fuel. The slower you go the farther you can get with the same amount of fuel. Cruising at slow speed your range increases tremendously; the downside being it takes a lot longer in real time waiting to get from point A to B (even at 1024x speed).

If you want to squeeze more mileage using the batteries you just need to cruise submerged till they hit 10% or less and then surface to recharge. Once they hit 100% submerge and repeat. This works well if you burn up too much fuel on patrol and need a few more hundred k's to make it back to dock; its a lot of work to do. :damn:

neron 02-23-08 01:10 AM

hi
if you do a search youll find some posts giving you best speed for each type
i think the vii 8 kts
the ix may be 11 not sure
just ask the nav officer for max range at current speed and adjust up and down one knot at a time
im sure you can get 45,000 kms out of a ix

skookum 02-23-08 01:21 AM

Best fuel speeds:

IIA and IID: 6 Knots

VIIB and VIIC: roughly 7 and a half knots.


If you ring in all stop while charging your batteries, you will burn nothing. Theoretically you could cruise around the world and not burn a drop of fuel.

ToySoldier 02-23-08 01:49 AM

Hello out there!

Quote:

Originally Posted by skookum
Best fuel speeds:

IIA and IID: 6 Knots

VIIB and VIIC: roughly 7 and a half knots.


If you ring in all stop while charging your batteries, you will burn nothing. Theoretically you could cruise around the world and not burn a drop of fuel.

Do I understand you right?
If I comand the LI to recharge the batterys the Boot donīt need fuel?
A bug????
I canīt believe this!!!
:o

In diesem Sinne
Gott mit Uns
Frank B. aus K.

Elmer Kosterman 02-23-08 07:09 AM

I'm pretty sure that using the electric engines doesn't save fuel because they have to be charged with the diesel engines anyway. Thus, using the electrics and then charging them on the surface uses more fuel than only using the diesels on the surface.

That said, one can certainly use the electric engines to get back to base after the diesel has run out, if one is close enough. If not, there used to be a cheat, whereby the batteries would be automatically recharged if out of fuel... something about surfacing and ordering the charge. I don't know for sure because I've never used it.

One thing to keep in mind is that the faster the electric engines are run, the faster the batteries will drain. On the surface, there is one ideal engine setting for optimal fuel consumption for normal cruising and another, much higher, setting for travelling while charging. This is because the single engine used for propulsion while charging needs to work harder to bring the boat up to its ideal speed.

Taz1969 02-23-08 08:01 AM

Quote:

Originally Posted by Elmer Kosterman
I'm pretty sure that using the electric engines doesn't save fuel because they have to be charged with the diesel engines anyway. Thus, using the electrics and then charging them on the surface uses more fuel than only using the diesels on the surface.

That said, one can certainly use the electric engines to get back to base after the diesel has run out, if one is close enough. If not, there used to be a cheat, whereby the batteries would be automatically recharged if out of fuel... something about surfacing and ordering the charge. I don't know for sure because I've never used it.

One thing to keep in mind is that the faster the electric engines are run, the faster the batteries will drain. On the surface, there is one ideal engine setting for optimal fuel consumption for normal cruising and another, much higher, setting for travelling while charging. This is because the single engine used for propulsion while charging needs to work harder to bring the boat up to its ideal speed.

I have limped a long ways with bingo fuel before,well not totally out but close.If u surface with engines stopped u will recharge the batteries without useing fuel although the diesels are running.If it does use fuel then i have never noticed the gauge move.So like someone else said earlier,i think u could cruise the world without useing any fuel if one wanted too

T.Von Hogan 02-23-08 08:14 AM

I set my IXB at 9 knots for the best fuel results.

Brag 02-23-08 09:55 AM

I found, 8 knots works well for me in a IXB.
Take along a good book, preferably mine, now available in USA, UK, Germany. You won't get bored, hehe. :up:

Sailor Steve 02-23-08 09:57 AM

Quote:

Originally Posted by Tessa
If you want to squeeze more mileage using the batteries you just need to cruise submerged till they hit 10% or less and then surface to recharge. Once they hit 100% submerge and repeat. This works well if you burn up too much fuel on patrol and need a few more hundred k's to make it back to dock; its a lot of work to do. :damn:

Too bad that wouldn't work in real life.

STEED 02-23-08 10:04 AM

There is a supply ship SE of Greenland if your that worried. :roll:

i_b_spectre 02-23-08 10:46 AM

There does seem to be a bug of sorts. Returning from my first foray across-the-pond, I was watching my fuel carefully, knowing it would be close. My navigator's prediction on maximum range at the given speed versus the distance-to-end indicated I would make it with some fuel to spare. Imagine my surprise when I ran out of fuel short of the milch cow as confirmed by the pull-out fuel gauge. Figuring I could crawl the remaining distance on batteries, I submerged and pressed on. However, my batteries ran out a few kms short, but when I surfaced, the diesels came online and I made it the rest of the way.

Lesson learned: the navigator's calculation of max distance is an estimate, not 100% reliable. I don't recall the sea state at the time, but the calculation may be based on "best case" with calm conditions, therefore subject to the effects of less than optimum weather. In this case, the bug worked in my favor, but I'd rather not rely on it for planned operations. It might not be a bad idea to plan your arrival with a 10%-20% reserve.

johnm 02-23-08 10:48 AM

I found 9 knots in a IXB works well, asking the N.O. distance at this speed helps to check it.

Since installing GW2 he always replies that that info is not available.

bertockamus 02-23-08 01:29 PM

Thanks for all the advice.:lurk:


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