Did this happen in real life?

tiger_tim_34 · 01-14-08, 06:51 AM

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 · 01-14-08, 07:02 AM

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 · 01-14-08, 07:07 AM

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 · 01-14-08, 08:01 AM

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.

Pisces · 01-14-08, 09:53 AM

Quote:

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 · 01-14-08, 09:57 AM

6 knots it is. Thank you.

Will resume stickleback terror duties with renewed confidence.

tiger_tim_34 · 01-14-08, 08:10 AM

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.

01-14-08, 06:51 AM	#1
tiger_tim_34 Gunner Join Date: Apr 2005 Posts: 93 Downloads: 5 Uploads: 0	Did this happen in real life? 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] Last edited by tiger_tim_34; 01-14-08 at 08:17 AM.

01-14-08, 07:02 AM	#2
Abd_von_Mumit The Old Man Join Date: Jan 2007 Location: Warszawa, Polska Posts: 1,453 Downloads: 46 Uploads: 4	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: __________________ Long, hard, wet and full of seamen. My precious. SH3+GWX+OLC — sunk x4, retired x2; SH5+TDW — still exploring My SH5 mods: EQuaTool - Elite Quality Map Tools, Patrol Routine Scripts, No Logo Intro Menu_Animation, Less Annoying Stopwatch Links: SH5 mods I use, FileFront, Manual plotting how-to

01-14-08, 08:01 AM	#4
seafarer Commodore Join Date: Feb 2005 Posts: 622 Downloads: 0 Uploads: 0	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. __________________ My Father's ship, HMCS Waskesiu (K330), sank U257 on 02/24/1944 running SHIII-1.4 with GWX2.1 and SHIV-1.5 with TMO/RSRDC/PE3.3 under MS Vista Home Premium 32-bit SP1 ACER AMD Athlon 64x2 4800+, 4GB DDR2 RAM, 400GB SATA HD Antec TruePower Trio 650watt PSU BFG GeForce 8800GT/OC 512MB VRAM, Samsung 216BW widescreen (1680x1050) LCD

01-14-08, 08:10 AM	#7
tiger_tim_34 Gunner Join Date: Apr 2005 Posts: 93 Downloads: 5 Uploads: 0	re: Type IIA mainly for training / local stuff 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. Last edited by tiger_tim_34; 01-14-08 at 08:28 AM.

01-14-08, 07:07 AM	#3
Uncle Goose Torpedoman Join Date: Dec 2007 Location: Belgium Posts: 113 Downloads: 1 Uploads: 0	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.

01-14-08, 09:57 AM	#6
tiger_tim_34 Gunner Join Date: Apr 2005 Posts: 93 Downloads: 5 Uploads: 0	6 knots it is. Thank you. Will resume stickleback terror duties with renewed confidence.