Fuel Efficiency and SOP...

Jarhead0331 · 03-25-07, 02:10 PM

Long time lurker, first time poster here...

Anyway, I seem to be having an issue with fuel efficiency. I've tried starting a career, but my first patrols seem to not go over too well. My biggest problem seems to be fuel. These cruises take me across the ocean and I find that I will not have enough fuel to make it back. Does your speed impact upon fuel consumption? If so, what is the most fuel efficient speed? I usually travel on the surface at standard, just because it seems right...What is standard operating procedure?

Also, when am I supposed to start running underwater? From a historic approach, at what point did sub commanders begin to spend more time below the surface than on it...is it a tactical consideration in terms of location, range of land-based aircraft, etc.? Or was there something in a FM somewhere that dictated this procedure?

To conserve fuel, I've tried running on electric, but those batteries wear down so fast and you never know when you're going to need them in an emergency!!!!

Thanks in advance...

Semper Fi

Banquet · 03-25-07, 02:24 PM

Hi Jarhead,

I think the most fuel efficient speed is 2/3. I too went at Standard on my first patrol and never made it back to Midway, let alone Pearl. 2/3 seems to work better but I still refit at Midway if I'm heading up to Japan.

For the electric batteries I think they deplete too fast. NVDrifter is hopefully going to do a mod that will fix that so you can run underwater for longer. US subs generally ran underwater during the day and on the surface at night. Certainly the one's patrolling near Japan did.. I'm not so sure what the operating procedure was for subs patrolling other area's.. I imagine it depended on whether the area was in range of Japanese aircraft (which would be a lot of places)

AirborneTD · 03-25-07, 02:25 PM

I usually run on the surface at about 2/3 speed until I get close to suspected air zones. I dive during the daylight hours (and some moonlit nights) and run submerged at around 2 knots speed. This keeps me on batteries all day and they won't go much below 50 percent.

With early war boats, I found I had to manually adjust the speed to around 7-10 knots or my fuel would be consumed too rapidly.

Running on batteries will not get you very far.

For War Patrols out of Pearl, I'll stop and top off at Midway if I'm heading over to Empire Pacific waters (or thereabouts).

Hope this helps

Jarhead0331 · 03-25-07, 02:26 PM

Thanks...refit! I didn't know you could do that...so I can pull into port at another base and refuel? I had actually meant to ask about that...

Banquet · 03-25-07, 02:30 PM

Yep, I plotted a course right into the harbour but as soon as you get close a popup box asks if you want to refit.. sorts you out for fuel, ammo, torps.. very useful indeed!

oblivionenigma · 03-25-07, 02:38 PM

Assuming the fuel consumption principle is the same as in SHIII, as a general rule, the slower you go, the farther you can go.
Standard should get you pretty far.. slower should get you even farther.

That said, you can go to any dock and chose to "refit" which I believe will get you more fuel.

Faamecanic · 03-25-07, 02:53 PM

With my Tambor class I set my speed to 9 kts (Maximum speed for 1/3 ahead slow). I made it from Midway (where I also top off as I am coming from Pearl) to the Imperial coast with only 25% of my fuel used.

As in SH3 I just play with the Knots setting unitl I hit the max speed that ahead slow 1/3 will give me ( the first speed setting on the telegraph is 1/3 I think)

Tigrone · 03-25-07, 04:45 PM

It was the same with a type IX in SH3. A steady 9 knots gave you a huge range and a good search zone coverage. You want to be able to stay out as long as you can with only: no more torps or running out of provisions forcing you in.

Samu* · 03-25-07, 06:55 PM

Hi Jarhead!

As stated here, usually the most efficient speed is the 1/3rd. But its pain in the *** to cross the ocean with that speed

..So 2nd best option is to use 2/3. Remember, when submerged the slower speed you are using, less likely enemy destroyers hear you.

You can safely travel at surface (and save batteries..) until you come under enemy air coverage. And even then you can stay surface if you dare

Umh, seriously depends on weather of course and other variables. Remember the difference how (far..) your crew will spot enemies if you´re surface drive versus you´re submerged.

03-25-07, 02:10 PM	#1
Jarhead0331 Swabbie Join Date: Mar 2007 Posts: 7 Downloads: 20 Uploads: 0	Fuel Efficiency and SOP... Long time lurker, first time poster here... Anyway, I seem to be having an issue with fuel efficiency. I've tried starting a career, but my first patrols seem to not go over too well. My biggest problem seems to be fuel. These cruises take me across the ocean and I find that I will not have enough fuel to make it back. Does your speed impact upon fuel consumption? If so, what is the most fuel efficient speed? I usually travel on the surface at standard, just because it seems right...What is standard operating procedure? Also, when am I supposed to start running underwater? From a historic approach, at what point did sub commanders begin to spend more time below the surface than on it...is it a tactical consideration in terms of location, range of land-based aircraft, etc.? Or was there something in a FM somewhere that dictated this procedure? To conserve fuel, I've tried running on electric, but those batteries wear down so fast and you never know when you're going to need them in an emergency!!!! Thanks in advance... Semper Fi

03-25-07, 02:25 PM	#3
AirborneTD Engineer Join Date: Nov 2004 Location: Pennsylvania, USA Posts: 204 Downloads: 23 Uploads: 0	I usually run on the surface at about 2/3 speed until I get close to suspected air zones. I dive during the daylight hours (and some moonlit nights) and run submerged at around 2 knots speed. This keeps me on batteries all day and they won't go much below 50 percent. With early war boats, I found I had to manually adjust the speed to around 7-10 knots or my fuel would be consumed too rapidly. Running on batteries will not get you very far. For War Patrols out of Pearl, I'll stop and top off at Midway if I'm heading over to Empire Pacific waters (or thereabouts). Hope this helps __________________ "You know, you might get surrounded." "We're paratroopers, Lieutenant. We're supposed to be surrounded." --Band of Brothers

03-25-07, 04:45 PM	#8
Tigrone Commander Join Date: Dec 2001 Location: Newport Beach, CA Posts: 470 Downloads: 41 Uploads: 0	9 knots should take you anywhere It was the same with a type IX in SH3. A steady 9 knots gave you a huge range and a good search zone coverage. You want to be able to stay out as long as you can with only: no more torps or running out of provisions forcing you in. __________________ Commander Hiram Cassedy: "Tigrone has saved the Air Force and is now returning to Iwo Jima with 28 rescued zoomies." B-29 SNUFFY & THE SHIF'LESS SKONKS among them. I've a broom at the mast said he, for the broom is a sign for me, that wherever I go, I sweep the mighty sea.

03-25-07, 06:55 PM	#9
Samu* Watch Join Date: Mar 2005 Location: Finland Posts: 29 Downloads: 1 Uploads: 0	Hi Jarhead! As stated here, usually the most efficient speed is the 1/3rd. But its pain in the *** to cross the ocean with that speed ..So 2nd best option is to use 2/3. Remember, when submerged the slower speed you are using, less likely enemy destroyers hear you. You can safely travel at surface (and save batteries..) until you come under enemy air coverage. And even then you can stay surface if you dare Umh, seriously depends on weather of course and other variables. Remember the difference how (far..) your crew will spot enemies if you´re surface drive versus you´re submerged. __________________ Meine Ehre Heist Treue "My loyalty is my honor" -The motto engraved on the belt buckles of SS troops.

03-25-07, 02:24 PM	#2
Banquet Machinist's Mate Join Date: Mar 2005 Posts: 122 Downloads: 0 Uploads: 0	Hi Jarhead, I think the most fuel efficient speed is 2/3. I too went at Standard on my first patrol and never made it back to Midway, let alone Pearl. 2/3 seems to work better but I still refit at Midway if I'm heading up to Japan. For the electric batteries I think they deplete too fast. NVDrifter is hopefully going to do a mod that will fix that so you can run underwater for longer. US subs generally ran underwater during the day and on the surface at night. Certainly the one's patrolling near Japan did.. I'm not so sure what the operating procedure was for subs patrolling other area's.. I imagine it depended on whether the area was in range of Japanese aircraft (which would be a lot of places)

03-25-07, 02:26 PM	#4
Jarhead0331 Swabbie Join Date: Mar 2007 Posts: 7 Downloads: 20 Uploads: 0	Thanks...refit! I didn't know you could do that...so I can pull into port at another base and refuel? I had actually meant to ask about that...

03-25-07, 02:30 PM	#5
Banquet Machinist's Mate Join Date: Mar 2005 Posts: 122 Downloads: 0 Uploads: 0	Yep, I plotted a course right into the harbour but as soon as you get close a popup box asks if you want to refit.. sorts you out for fuel, ammo, torps.. very useful indeed!

03-25-07, 02:38 PM	#6
oblivionenigma Watch Join Date: Mar 2007 Posts: 19 Downloads: 8 Uploads: 0	Assuming the fuel consumption principle is the same as in SHIII, as a general rule, the slower you go, the farther you can go. Standard should get you pretty far.. slower should get you even farther. That said, you can go to any dock and chose to "refit" which I believe will get you more fuel.

03-25-07, 02:53 PM	#7
Faamecanic Ace of the Deep Join Date: May 2005 Location: Off your Stb side with good solution Posts: 1,065 Downloads: 44 Uploads: 0	With my Tambor class I set my speed to 9 kts (Maximum speed for 1/3 ahead slow). I made it from Midway (where I also top off as I am coming from Pearl) to the Imperial coast with only 25% of my fuel used. As in SH3 I just play with the Knots setting unitl I hit the max speed that ahead slow 1/3 will give me ( the first speed setting on the telegraph is 1/3 I think)