Did this happen in real life?

[tiger_tim_34]

A commander of a Type IIA U-Boat, with early rubbish batteries, is ordered to sail from Kiel and patrol AF84 for 24 hours and then sail back again. He 'porpoises' all the way there to maximise his range, he sits just within the patrol square for 24 hours to qualify for 'patrolling' it and then he heads home.

Only to run out of fuel.

How did they manage it? There's barely enough fuel to return to Wilhelmshaven.

[Note: Using GWX2.0]

[Abd_von_Mumit]

What date is it? Are he Norwegian ports friendly allready? If so, couldn't it be intended by BdU that you report in Bergen instead of home port? :hmm:

[Uncle Goose]

This would probably not happen IRL, Type II subs were in most cases used as training boats or as coastal defence, BDU would rather have send a type VII to suchs waters.

[seafarer]

Also, porpoising will not maximize range. Every time you surface you will burn excessive fuel as you are driving the boat and charging the batteries (look at your engine rpm gauges on any boat and you will see one engine, the one charging, running at high rpms regardless of boat speed).

In any class of boat, you will get your maximum range by manually setting the speed to the most efficient (eg. in a VII, that would be about 8 knots) and minimizing submerged time (and hence battery charging time).

I don't know about type II's as I never command them, but for example, running at 8 knots in a VIIB or C, it is entirely possible to achieve operational patrols that cover 15,000-20,000km (eg. to the US coast and back, with plenty of patrol time while off NA).

I'd imagine, and someone can correct me, that optimal speed (optimal in terms of stretching fuel endurance to the maximum possible) for a type II is likely around 5 or 6 knots, steady cruising.

[tiger_tim_34]

Abd_von_Mumit... it said 'Kiel to Kiel' in my orders, unless I missed something. It would make a great deal of sense to park in Bergen.

Uncle Goose... I thought so. Sorry, forgot to mention that I'm at the very start of the war.

Seafarer... if that is so (and it makes sense) you will have saved me a huge headache! I'm pretty sure my fuel depletes at the same rate, whether I'm recharging or not. <-- Can anyone confirm this?

Right, I'm off for a duck-shoot in Hartlepool harbour.

[Pisces]

Originally Posted by seafarer

...
I'd imagine, and someone can correct me, that optimal speed (optimal in terms of stretching fuel endurance to the maximum possible) for a type II is likely around 5 or 6 knots, steady cruising.

Affirmative, I've been to that patrol location in a type IIa (GWX 1.03, sep. or oct. '39) and had enough fuel left to terrorize (asmuch as that 'stickleback' can do anyway) the Orkney-Scapa gap also when I stick to sailing at 6 knots. A type IIa seems to get around 6000km out of it's tank that way.

[tiger_tim_34]

6 knots it is. Thank you.

Will resume stickleback terror duties with renewed confidence.

[Wilcke]

Yeah, its a slow haul to eeck out the mileage....but I just use SH Commander to assign a nearby sector to patrol complete my time and then go "hunting" at my leisure. They were classed as 'coastal patrol' boats afterall.

[Abd_von_Mumit]

Originally Posted by Wilcke

Yeah, its a slow haul to eeck out the mileage....but I just use SH Commander to assign a nearby sector to patrol complete my time and then go "hunting" at my leisure. They were classed as 'coastal patrol' boats afterall.

But you know... it's a war. Your needs are always bigger than your abilities and you have to make choices on a daily basis. One of the choices could be sending 'coastal' U-Boots to patrol deeper in the sea, as there were too few of type VII. And you, as a Kaleun, wouldn't have much to do about that once ordered, as an order is an order.

If BdU decides to send me to Japan in a type VII, I'll do my best to get there. Who said you always have to sink those tankers? From time to time you can buy some gas from them instead.

[Blacklight]

You think you have problems... (I brought this upon myself.. I have "breakdowns/sabotage" enabled to enhance my realism)....

I drive a VIIB out of Wilhelmshaven. Lately, BDU seems to like to send me to patrol all the way to the middle of the ocean, and this time to the southern coast of Africa meaning that I have to stop at a milk cow in Spain along the way. Anyway.. I'm going up around the northern coast of Ireland heading at about 7-9 knots. I submerge for a couple hours to listen for contacts because in that area, there are usually so many allied ships that I have to torpedo them just to get them out of the way. When I surface, my engine konks out. Even with a fresh crew in the engine room with the green bar full, my speed has dropped considerably. The weather is clear with winds of 5 knots so it isn't that. Now, at standard speed, when not recharging batteries, I get 3 knots. At flank, I get 4 knots or maybe 5 occasionally. Submerged, I'm stuck with a maximum of 3 knots at flank. To make matters worse, I seem to be leaking fuel. My fuel is being used up at an accelerated rate. I now doubt that I have enough fuel to make it back to Wilhelmshaven or the nearest milk cow for repairs. (At least according to my navigator).

Ironically, I noticed that one of the crew members I placed in the engine room was the one I used SHIII Comander to rename "Bernard"

Well.. we're going to try to limp off toward that milk cow... if we need a tow.. we'll have to get a tow I guess. Do us U-Boat captains have any kind of U-Boat AAA we can call ? :rotfl: