Limited Fuel

GoldenRivet · 02-05-09, 12:50 AM

The best procedure for long range cruise performance in the type VII is to set the speed to 8 - 9 knots.

This should yield the longest range and best fuel economy.

The best way to get an accurate measure of your remaining range is to set time compression to about 512x and ask the navigator to report the remaining range about every 2 or 3 seconds until you have 4 or 5 reports.

you can do the math by pencil and paper or just guess at an average of the 4 or 5 numbers. this average is your best estimate.

usually his first estimate is in error by a large margin, so it is best to ask for 4 or 5.

If you are in any kind of rough sea, this will affect the reported range substantially.

hope this information helps!

Robert Fulton · 02-05-09, 01:41 PM

Quote:

Originally Posted by GoldenRivet

The best procedure for long range cruise performance in the type VII is to set the speed to 8 - 9 knots. This should yield the longest range and best fuel economy.

The best way to get an accurate measure of your remaining range is to set time compression to about 512x and ask the navigator to report the remaining range about every 2 or 3 seconds until you have 4 or 5 reports.

you can do the math by pencil and paper or just guess at an average of the 4 or 5 numbers. this average is your best estimate.

usually his first estimate is in error by a large margin, so it is best to ask for 4 or 5.

...

Could you please expand on this a bit. Why does 512x TC improve the estimates? I have been getting estimates at 1x TC thinking they were close to accurate.

Also, my navigator advises me that we get much better range at 3kts than we do at 7kts. Does range jump higher at 8-9kts from what it is at 7kts or is do I need to replace my navigator when I get back to port?

GoldenRivet · 02-05-09, 01:55 PM

it improves the estimates because you get multiple estimates over a longer period of time versus getting the same number of estimates over a period of a minute or two.

here is why.

your navigator will give you the estimate at the current speed... not what you have ordered.

so for example - if your bow is burying itself into a roller when you give the order to report range, and at the exact same time your speed is dropping due to hitting head first into the wave... your navigator is giving you an estimate based on that speed... not what you have ordered.

i have seen as much as a 50% margin or error in his estimates because of rough weather.

he once told me something like 6,000 KM and in the very next report some minutes later told me 11,000 Km (give or take)

so getting multiple reports spread out over the span of say 30 minutes to an hour in game is the best practice IMHO.

my process is to order the 4 or 5 estimates over the span of an hour.

then i will average them and subtract 1,000 km

this will give me an estimate with a 1,000 km reserve

Robert Fulton · 02-05-09, 02:05 PM

Thanks. Good explanation.

What about the my navigator, though? Is he incorrect in advising me that I get better range at 3kts?

Freiwillige · 02-05-09, 02:23 PM

Its like any combustion engine in that the lower the RPMs' the lower the fuel consumption. You have to find that balance between fast enough to get there and fuel savings.

Its like your car. Sure you could get a hell of a lot further per tank if you idled everywhere you went at 15 MPH but you would take allot longer to get there. So you do 40 on average which is a good compromise for speed vs fuel savings

Piggy · 02-05-09, 02:29 PM

Quote:

Originally Posted by Robert Fulton

Thanks. Good explanation.

What about the my navigator, though? Is he incorrect in advising me that I get better range at 3kts?

Ive always found my range esitmated range at 3 knots is a lot less then it is at 9 knots, even though Im burning much less fuel.

The reason I say this is because Ive noticed the Navigator gives you the most range at ~9knots, but if you go to 3 knots your esitmated range is quite a bit lower even though you're burning a lot less fuel. At 3 knots you can stay on your patrol area for a long time, but you wont get very far at that speed?

I imagine endurance and range to be two different things?

If that makes any sense?

GoldenRivet · 02-05-09, 02:50 PM

endurance is how long your engine will run over time

range is how far you will go at the current speed

as freiwillige pointed out you have to strike a balance between speed and efficiency. too slow and you dont cover much ground, too fast and you run out of fuel sooner

i have found that - if i want to go a LONG way on a tank of gas then right about 8 or 9 knots is perfect.

You can really stretch the fuel if you remain submerged all day long at ahead slow and then run surfaced all night long at 8-9 knots.

another problem we run into in SH3....

the map is a "Mercator projection"... ie it is a flat surface representation of a spherical world.

The SH3 world gets its information as to where land and ocean are from the map... so the world in SH3 itself is in fact completely flat too!!

the further you go from the equator north or south, the more distorted the map becomes, this is why Greenland on the SH3 map nearly dwarfs north America.

ideally, the game would use curved nautical charts... which - if you had a large enough wall you could tape all the nautical charts together end to end and they would form a massive circle of charts.

the end result, even though a real life U-boat would have no real problem leaving St. nazaire and heading to New York... the game has added a significant distance between the two locations by "flattening" the earth.... so GWX crew had to mod the ranges of the U-boats to compensate for this mathematical travisty.

Piggy · 02-05-09, 03:06 PM

Quote:

Originally Posted by GoldenRivet

the end result, even though a real life U-boat would have no real problem leaving St. nazaire and heading to New York... the game has added a significant distance between the two locations by "flattening" the earth.... so GWX crew had to mod the ranges of the U-boats to compensate for this mathematical travisty.

Yeah I noticed that the range my navigator gives me in my VIIC is more then that of a IXC, quite a bit more...

Must be using some new fangled "compressed fuel oil tank".. top secret!

PS: Before I realized how the map was stretched I was making runs to north america via a circular route north, somewhat like how an airplane would fly. Its shorter to go up north, across and then south rather straight across the (or around) the middle of the atlantic. Of course this doesnt make a difference in game, but it feels "real"...

02-05-09, 12:50 AM	#1
GoldenRivet Subsim Aviator Join Date: Mar 2007 Location: Texas Posts: 8,726 Downloads: 146 Uploads: 0	The best procedure for long range cruise performance in the type VII is to set the speed to 8 - 9 knots. This should yield the longest range and best fuel economy. The best way to get an accurate measure of your remaining range is to set time compression to about 512x and ask the navigator to report the remaining range about every 2 or 3 seconds until you have 4 or 5 reports. you can do the math by pencil and paper or just guess at an average of the 4 or 5 numbers. this average is your best estimate. usually his first estimate is in error by a large margin, so it is best to ask for 4 or 5. If you are in any kind of rough sea, this will affect the reported range substantially. hope this information helps! __________________

02-05-09, 01:55 PM	#3
GoldenRivet Subsim Aviator Join Date: Mar 2007 Location: Texas Posts: 8,726 Downloads: 146 Uploads: 0	it improves the estimates because you get multiple estimates over a longer period of time versus getting the same number of estimates over a period of a minute or two. here is why. your navigator will give you the estimate at the current speed... not what you have ordered. so for example - if your bow is burying itself into a roller when you give the order to report range, and at the exact same time your speed is dropping due to hitting head first into the wave... your navigator is giving you an estimate based on that speed... not what you have ordered. i have seen as much as a 50% margin or error in his estimates because of rough weather. he once told me something like 6,000 KM and in the very next report some minutes later told me 11,000 Km (give or take) so getting multiple reports spread out over the span of say 30 minutes to an hour in game is the best practice IMHO. my process is to order the 4 or 5 estimates over the span of an hour. then i will average them and subtract 1,000 km this will give me an estimate with a 1,000 km reserve __________________

02-05-09, 02:50 PM	#7
GoldenRivet Subsim Aviator Join Date: Mar 2007 Location: Texas Posts: 8,726 Downloads: 146 Uploads: 0	endurance is how long your engine will run over time range is how far you will go at the current speed as freiwillige pointed out you have to strike a balance between speed and efficiency. too slow and you dont cover much ground, too fast and you run out of fuel sooner i have found that - if i want to go a LONG way on a tank of gas then right about 8 or 9 knots is perfect. You can really stretch the fuel if you remain submerged all day long at ahead slow and then run surfaced all night long at 8-9 knots. another problem we run into in SH3.... the map is a "Mercator projection"... ie it is a flat surface representation of a spherical world. The SH3 world gets its information as to where land and ocean are from the map... so the world in SH3 itself is in fact completely flat too!! the further you go from the equator north or south, the more distorted the map becomes, this is why Greenland on the SH3 map nearly dwarfs north America. ideally, the game would use curved nautical charts... which - if you had a large enough wall you could tape all the nautical charts together end to end and they would form a massive circle of charts. the end result, even though a real life U-boat would have no real problem leaving St. nazaire and heading to New York... the game has added a significant distance between the two locations by "flattening" the earth.... so GWX crew had to mod the ranges of the U-boats to compensate for this mathematical travisty. __________________

02-05-09, 02:05 PM	#4
Robert Fulton Mate Join Date: Oct 2008 Location: USA Posts: 59 Downloads: 2 Uploads: 0	Thanks. Good explanation. What about the my navigator, though? Is he incorrect in advising me that I get better range at 3kts?

02-05-09, 02:23 PM	#5
Freiwillige The Old Man Join Date: Mar 2008 Location: Phx. Az Posts: 1,458 Downloads: 24 Uploads: 0	Its like any combustion engine in that the lower the RPMs' the lower the fuel consumption. You have to find that balance between fast enough to get there and fuel savings. Its like your car. Sure you could get a hell of a lot further per tank if you idled everywhere you went at 15 MPH but you would take allot longer to get there. So you do 40 on average which is a good compromise for speed vs fuel savings