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Old 09-12-06, 09:34 AM   #1
Tolkemec
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Default Optimum speed for Type II

Hello everybody,

I have noticed something unusual (for me, who don't know a thing about engines). Type II sub apparently uses more fuel at <5 and >5 knots. So the optimum speed is 5 knots. Do you know if this this normal?

I have just been transfered to Wilhelmshaven and asked to patrol BE39 AREA which is pretty far away... I will go for the English Channel, though Subgen tells me it is now closed due to high risk...

Thanks!
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Old 09-12-06, 10:01 AM   #2
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Hello

It's been a long time since I've used a type II U-Boat so I'm not too sure on the specs. But the general rule (for me at least) is to go at ahead slow at all times. That way you conserve fuel and you can go quite a long way. Another thing you can do is to set the speed manually to whichever value you require.

As far as the channel is concerned I wouldn’t go through it. It’s full of mines (I’m playing GW) and destroyers.

I hope this makes sense and it’s helpful.
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Old 09-12-06, 10:19 AM   #3
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I vaguely remember in my youth when I commanded a dugout that cruising at ahead slow was the way forward due to the pitiful fuel capacity.

In my VIIB I always cruise at 1/3 which gives a good balance between fuel consumption, speed and range.
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Old 09-12-06, 10:25 AM   #4
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I also travel at 1/3. I find that I run out of torpedoes well before I run out of fuel. When I'm out of fish, I run flank speed back home.
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Old 09-12-06, 12:01 PM   #5
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In ALL subs it's the same thing: the slowest possible speed setting is NOT the most fuel efficient. I you're having trouble comprehending that, just remember your own car's cruising speed (the speed at which it is most fuel efficient) and you'll find that it occurs at about 90km/h... definetly not slow. Hammering the point even more, lets remember that cars give better milage per galon of fuel during highway driving versus the milage they get during city driving.

For a long time the gurus on this forum have pointed us toward 9knts as the most efficient speed for virtualy ALL subs. But I personally don't micro-manage that number too much... I just pres the "2" key on the keyboard and let the ship fall into it's own natural speed depending on the weather.
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Old 09-12-06, 03:36 PM   #6
Myxale
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DAnte has a point guys! The Type II is a small boot and bound to run out of Oil anyway...so why not use most of it! :hmm:
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Old 09-12-06, 04:46 PM   #7
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Hmm, very interesting. Seems to me like its time to call in the experts. Lets hear everyone's personal cruising speed for whatever reason be it fuel efficiency or whatever other reason you have. Break it dowm by type if you can.

GO!
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Old 09-12-06, 04:49 PM   #8
kylania
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Ahead One Third seems to be the best for me for range. So far that's on my VII and IX boats.
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Old 09-12-06, 05:05 PM   #9
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Nine knots.
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Old 09-12-06, 08:16 PM   #10
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I'm a nine-knotter myself. Good for those historically accurate 4 and 5 week patrols. As Gromit said though, I usually run out of fish before I run out of oil.
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Old 09-12-06, 09:03 PM   #11
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If I'm confined to the North Sea, 2/3. If I'm going over to Poland, 1/3...except for the time I decided to go there on the first day of the war and used full speed out and 1/3 back.
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Old 09-12-06, 10:42 PM   #12
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On the IIa for cruise-I click the telegraph and manually put it on 7 kts--still keeps it at "alead slow" even though just clicking on ahead slow by itself will usually only give you 5-6 kts .
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Old 09-13-06, 03:26 AM   #13
Myxale
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10knots for the IX is most effective! IMO
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Old 09-13-06, 04:20 AM   #14
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Default Hullspeed

Every sailor knows that hull has its own ideal speed.
When the Germans finally put all efforts to making the electro boat they found ideal hull for fast going boat modell. It even goes faster under the water than on surface.

In my hometown they make ship engines. (Wartsila) and its known here that its not question of the engine how fast ship goes its question of how the hull is designed.

It is quite good handled in the sim also the hull speed and modelled how the boat behave. When you drive a IIA it stop quite soon when go all stop, then when you drive XXI boat the boat glide and glide long time after all stop order. You must order reverse if need to stop it.

Most ships with round bottom have a hull speed of 8 knots, then flatbottoms have it much higher (like DDs) so a efficient and economic speed is there around 7 - 9 knots.

I tested this also by driving with all speeds and asking navigator how long does we travel with that given speed and when the speed rises the amount of kilometers we travel was quite the same, but time takes much less. (tested wit IID modell)

So I come to a solution that I drive standard speed between patrol area and base.
The BDU dont give long patrols to a IIA modell boat anyway.

Other issue is that I would like to travell Kiel canal, but its frustating when it takes so long time when the time acceletor drops to 16 there.
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Old 09-13-06, 12:28 PM   #15
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slow in my IX boat.
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