Graf Paper
02-07-08, 08:15 PM
Though this has likely been covered before, the recent influx of many Kaleuns fresh out of training and running short on fuel in their first patrols has prompted me to chip in my own two cents on the matter.
Being a fairly recent graduate of the Academy, the lessons I learned early on about managing fuel are still fresh in my mind. I now have eight patrols under my belt and have never run out of fuel getting back home.
I'd have to say the hardest thing for any new Kaleun to get the hang of, next to crew management, is managing fuel.
Direct experience for my own command is this...
Type IIA stock configuration best speed for maximum range is 5 kts.
Type VIIB stock configuration best speed for maximum range is 7 kts.
Type VIIB upgraded with GWK turbo diesels best speed for maximum range is 8 kts.
If you're stationed at Kiel or Flensburg in a type II boat it is highly recommended you use the Kiel Canal to shave some distance off your trip when travelling to patrol grids south of the Firth Of Forth. Use SH3 Commander to change your time compression max setting when near land from 4 to 512 or else transiting the Kiel Canal is about as much fun as having a root canal at the dentist!
To find out what speed will give you the best range for your particular boat, stock or upgraded, is to simply set a speed in calm seas and then ask your Navigator to report the Maximum Range At Current Speed.
His answers can vary by quite a bit each time you ask, so it is best to ask about three or four times spread out over a few minutes of mission time. This will give you a rough idea of the average range at any given speed.
Bad weather, high seas, running with decks awash, and sprinting to intercept targets will cause you to burn more fuel. The rough seas also reduce your speed by as much as 3-4kts below what you ordered due to the boat nosing into waves and the stern heaving out of the water, exposing the props. Having decks awash will similarly affect your boat and reduce speed by 1-2kts.
Don't take your fuel gauges too seriously. I find them to be horribly inaccurate and impossible to read the markings, especially the one that is part of the slideout gauges when you point your mouse at the lower left side of the screen.
The Chief Executive officer's gauges that pop up when you ask him to report are more accurate, especially for battery and CO2 levels, but the Navigator's report for Maximum Range At Current Speed is much more reliable when you need to know if you have enough fuel to make it home (so long as you can maintain your speed in calm seas).
You also need to be aware that dashing off at Ahead Full or Ahead Flank to catch a convoy or task force that shows up two or three grids away will seriously eat your fuel reserves. It's usually just not worth the trouble to do that. Save your fuel for intercepting targets close to your course or in your patrol zone.
You can catch up to a slow moving vessel fairly well at Ahead 1/3 (near) or Ahead Standard (far) if you plot your intercept course correctly.
Vessels moving at medium speeds means you need Ahead Full (near) or Ahead Flank (far) speed.
For vessels reported as moving Fast or Very Fast, forget it unless you're lucky(?) enough to already be positioned ahead of their course.
Ahead Flank will burn fuel far more than you expect and so use of it should be reserved for evasive maneuvers, attack maneuvers, and quickly getting ahead of a target over short distances for setting up an attack.
Submerging to run on batteries to conserve fuel is a mistake many new kaleuns make. The fuel consumption while recharging the batteries more or less cancels out any fuel-saving benfits of running submerged. While it is true you're not using any fuel when cruising submerged you will use fuel recharging your batteries because one engine powers the recharge generator, leaving one engine to propel the boat at reduced speed (and use more fuel).
Bear in mind that U-Boats are very limited with batteries. My VIIB can only stay under for long periods at 3 kts or less, 2 kts being the ideal for best range. Faster speeds consume battery power rapidly.
Submerge only when doing a hydrophone check, avoiding contact with the enemy, making a torpdeo run against a target, or to go under very stormy or rough seas when remaining surfaced would consume more fuel than recharging the batteries later or you need to rest your crew in the quieter depths.
Remember, U-Boats are slow compared to many other ships, especially warships, and it is just not practical to attempt intercepting targets that are very far away or moving fast. Keep your speed set to whatever gives you the best range and stick to it while cruising unless you're intercepting a contact, attacking a target, or avoiding an enemy.
Following these guidelines means I usually have more than enough fuel to sail from Kiel to near Scapa Flow for a 24-hr patrol and then go around to the Irish coast for some deep-water convoy attacks before heading home in my trusty Type VIIB.
Being a fairly recent graduate of the Academy, the lessons I learned early on about managing fuel are still fresh in my mind. I now have eight patrols under my belt and have never run out of fuel getting back home.
I'd have to say the hardest thing for any new Kaleun to get the hang of, next to crew management, is managing fuel.
Direct experience for my own command is this...
Type IIA stock configuration best speed for maximum range is 5 kts.
Type VIIB stock configuration best speed for maximum range is 7 kts.
Type VIIB upgraded with GWK turbo diesels best speed for maximum range is 8 kts.
If you're stationed at Kiel or Flensburg in a type II boat it is highly recommended you use the Kiel Canal to shave some distance off your trip when travelling to patrol grids south of the Firth Of Forth. Use SH3 Commander to change your time compression max setting when near land from 4 to 512 or else transiting the Kiel Canal is about as much fun as having a root canal at the dentist!
To find out what speed will give you the best range for your particular boat, stock or upgraded, is to simply set a speed in calm seas and then ask your Navigator to report the Maximum Range At Current Speed.
His answers can vary by quite a bit each time you ask, so it is best to ask about three or four times spread out over a few minutes of mission time. This will give you a rough idea of the average range at any given speed.
Bad weather, high seas, running with decks awash, and sprinting to intercept targets will cause you to burn more fuel. The rough seas also reduce your speed by as much as 3-4kts below what you ordered due to the boat nosing into waves and the stern heaving out of the water, exposing the props. Having decks awash will similarly affect your boat and reduce speed by 1-2kts.
Don't take your fuel gauges too seriously. I find them to be horribly inaccurate and impossible to read the markings, especially the one that is part of the slideout gauges when you point your mouse at the lower left side of the screen.
The Chief Executive officer's gauges that pop up when you ask him to report are more accurate, especially for battery and CO2 levels, but the Navigator's report for Maximum Range At Current Speed is much more reliable when you need to know if you have enough fuel to make it home (so long as you can maintain your speed in calm seas).
You also need to be aware that dashing off at Ahead Full or Ahead Flank to catch a convoy or task force that shows up two or three grids away will seriously eat your fuel reserves. It's usually just not worth the trouble to do that. Save your fuel for intercepting targets close to your course or in your patrol zone.
You can catch up to a slow moving vessel fairly well at Ahead 1/3 (near) or Ahead Standard (far) if you plot your intercept course correctly.
Vessels moving at medium speeds means you need Ahead Full (near) or Ahead Flank (far) speed.
For vessels reported as moving Fast or Very Fast, forget it unless you're lucky(?) enough to already be positioned ahead of their course.
Ahead Flank will burn fuel far more than you expect and so use of it should be reserved for evasive maneuvers, attack maneuvers, and quickly getting ahead of a target over short distances for setting up an attack.
Submerging to run on batteries to conserve fuel is a mistake many new kaleuns make. The fuel consumption while recharging the batteries more or less cancels out any fuel-saving benfits of running submerged. While it is true you're not using any fuel when cruising submerged you will use fuel recharging your batteries because one engine powers the recharge generator, leaving one engine to propel the boat at reduced speed (and use more fuel).
Bear in mind that U-Boats are very limited with batteries. My VIIB can only stay under for long periods at 3 kts or less, 2 kts being the ideal for best range. Faster speeds consume battery power rapidly.
Submerge only when doing a hydrophone check, avoiding contact with the enemy, making a torpdeo run against a target, or to go under very stormy or rough seas when remaining surfaced would consume more fuel than recharging the batteries later or you need to rest your crew in the quieter depths.
Remember, U-Boats are slow compared to many other ships, especially warships, and it is just not practical to attempt intercepting targets that are very far away or moving fast. Keep your speed set to whatever gives you the best range and stick to it while cruising unless you're intercepting a contact, attacking a target, or avoiding an enemy.
Following these guidelines means I usually have more than enough fuel to sail from Kiel to near Scapa Flow for a 24-hr patrol and then go around to the Irish coast for some deep-water convoy attacks before heading home in my trusty Type VIIB.