What In Gods Name Are You Babbeling About?

[joho]

When I ask you -"Maximum range at current speed?" you give me a figure and then I ask you -"Range to course end"? and you give me another figure. If the first figure is higher then the second I expect us to reach port safe and sound.

NOW YOU TELL ME WE ARE OUT OF DIESEL AND WE STILL HAVE 500 km TO GO.
So I ask again -"Maximum range at current speed"? And you tell me 800 km ARE YOU NUTS!!!! HOW THE HELL ARE WE GOING 800 km WITH EMPTY FUEL TANKS HUH ????
Should I raise the periscope, hang my trouser in it and SAIL BACK TO WILHELMSHAFEN???

Well I got some bad news and some good news for you my freind. The bad news is I am transfering you of this boat, I dont ever want to see you again. The good news is I will wait with the transfer until we have been towed back to port so you wont have to swim back. You dumb son of a bitch!

Now is there anybod who can tell me what this idiot is talking about and can anybody give me a way to use up to 90% of the fuel without risking to get stuck dead in the water just because the navigator cant count?

[GoldenRivet]

your navigation officer will tell you the exact range at the current speed every time without error... the problem is, your speed fluctuates slightly with every wave you hit.

one second your doing 9 knots, the next your doing 8.3, the next your doing 10 and this speed fluctuation can occur over the course of a few seconds depending on sea state. - especially if you ask him under time compression. which if that is the case you may be asking him your range when your speed has dipped to a more economic level... but as soon as he tells you it speeds back up to a less economic level of fuel consumption.

so what you have to do is ask him about 5 or 6 times in a row and then average the 6 numbers he tells you, because they will all be slightly different.

then and only then will you have a good reliable estimate on the range.

better luck next time

[meduza]

Your CE tells you that you're out of fuel while you still have a small reserve left. A few times I "ran of the fuel" in front of the port, but still managed to get in with the diesels running.

I found that the navigator's prediction is pretty accurate, if the sea condition remains unchanged.

[Brag]

You can't rely on Bernard for accurate endurance.

[joho]

But I mean how can he be 800km of the chart, I get the message We are out of diesel.
And whan I ask he says maximum range at current speed 800 km.

Anyway is it a good rule to never go beneath 1000 km max range, like better safe than sorry?

[Paul_IronCoffin]

To my mind (and no doubt probably wrong) "Maximum range at current speed" & "Range to course end" are different questions.

'Max Range..' is probably the range following Great Circle navigation, ie. in a straight line across the surface of a sphere.

'Range to course end', seems to be exactly that. Distance to go before you reach the end of your course tracks - no matter what bizarre course changes that might involve.

cheers
Paul

[Steeltrap]

I've never really understood how so many people come to run out of fuel, unless they are risking a really long haul to the USA for example.

For starters, u-boats typically run at around 10kts. If you are constantly wanting to go faster because you are impatient, then you're wasting fuel and will run out of it eventually.

You can get greater range by selecting speed in kts rather than just ordering a telegraph setting. At ahead 2/3 you'll tend to do around 6kts, but you can get it to 7-8kts and still be at 2/3.

I use greater speeds only if in pursuit of something. I also use it on the home stretch, but am always careful about leaving at least a 1000km estimate from the navigator in my calculations.

I've never run out of fuel, even when doing a fair amount of the return leg at full.

Bottom line is you don't run when you can walk (modest speed will get you there with plenty of fuel to use for something important), don't run around at standard when you're in a target area (7kts is plenty, and in many weather conditions you're better served being at 30-40m at 1kt), and don't expect to get your fuel estimate down to the last litre when coming home.

[GoldenRivet]

Yeah i agree.

Except for a few rare occasions... I have almost never docked back at home port with less than 1/4 of a tank.

[Paul_IronCoffin]

I'm a pilot and fully understand the difference between available range and course range. Usually the former is far longer than the latter. It's not rocket science.

[scratch81]

i always run out of eels long before i run out of fuel. but if i ever do run out of fuel, im gonna tie a rope to Bernards waist and make him pull us into port.

[meduza]

I never actually ran out of fuel, but (as I already mentioned), on few occasions I was so low that the CE reported I'm out of fuel. That was during the '42 when I was patroling US coast on type IXB.

[Dekessey]

nm.

[gAiNiAc]

Originally Posted by Steeltrap

I've never really understood how so many people come to run out of fuel, unless they are risking a really long haul to the USA for example.

For starters, u-boats typically run at around 10kts. If you are constantly wanting to go faster because you are impatient, then you're wasting fuel and will run out of it eventually.

You can get greater range by selecting speed in kts rather than just ordering a telegraph setting. At ahead 2/3 you'll tend to do around 6kts, but you can get it to 7-8kts and still be at 2/3.

I use greater speeds only if in pursuit of something. I also use it on the home stretch, but am always careful about leaving at least a 1000km estimate from the navigator in my calculations.

I've never run out of fuel, even when doing a fair amount of the return leg at full.

Bottom line is you don't run when you can walk (modest speed will get you there with plenty of fuel to use for something important), don't run around at standard when you're in a target area (7kts is plenty, and in many weather conditions you're better served being at 30-40m at 1kt), and don't expect to get your fuel estimate down to the last litre when coming home.

Yup. I cruise in the Type 7's at 8 knots. Plenty of gas.

[gAiNiAc]

Originally Posted by Steeltrap

I've never really understood how so many people come to run out of fuel, unless they are risking a really long haul to the USA for example.

For starters, u-boats typically run at around 10kts. If you are constantly wanting to go faster because you are impatient, then you're wasting fuel and will run out of it eventually.

You can get greater range by selecting speed in kts rather than just ordering a telegraph setting. At ahead 2/3 you'll tend to do around 6kts, but you can get it to 7-8kts and still be at 2/3.

I use greater speeds only if in pursuit of something. I also use it on the home stretch, but am always careful about leaving at least a 1000km estimate from the navigator in my calculations.

I've never run out of fuel, even when doing a fair amount of the return leg at full.

Bottom line is you don't run when you can walk (modest speed will get you there with plenty of fuel to use for something important), don't run around at standard when you're in a target area (7kts is plenty, and in many weather conditions you're better served being at 30-40m at 1kt), and don't expect to get your fuel estimate down to the last litre when coming home.

Yup. I cruise in the Type 7's at 8 knots. Plenty of gas.

[tomoose]

I've found the reports to be fairly accurate, at least accurate enough that I know when to head home. The other aspect is, depending on the sea state, whether to adjust engine speed to gain more range.