General Discussions  
This is the place to discuss general issues related to the U-boat war or the war at sea in WWII. 
Underwater speed and range
Posted by: SuperKraut ()
Date: December 20, 2000 09:39AM

<HTML>The underwater top speed of the XXI is a bit academic since the batteries were flat in around 40 minutes. Note that the battery capacity at quick discharge (1 hr.) is about 1/3 of what it is at slow discharge (100 hrs.) The battery range of an XXI at top speed was only around 12 NM, but it could run 365 NM at 5 knots. The big advantage was the long range at medium speed, for example 110 NM at 10 knots. Just for comparison, a VII C could only go 80 NM at 4 knots and around 20 NM at its top speed of 7.6 knots.

BTW, the XXI as built had some voltage drop problems with the electrical system which were not foreseen and therefore battery life at top speed and available maximum power were below design levels.

Your comment on high speed dives is interesting and it was probably the best use of the high top speed. It would only take a power burst of a few minutes to get down to 200 meters.

Incidentally, the time to dive was an important issue in connection with the XXI top speed. Depending on the size of the flood openings, the top speed varied by almost 1 knot. Using the small flood openings and assuming the voltage drop problem was fixed, the XXI could make 18 knots on battery and, of course, have a longer range at medium speed.

Regards,
SuperKraut</HTML>

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Subject Written By Posted
type xxi phil 12/17/2000 12:41PM
RE: type xxi David W 12/18/2000 06:36AM
RE: type xxi Dietzsch 12/18/2000 09:12AM
RE: type xxi Rainer Bruns 12/18/2000 01:35PM
RE: type xxi Nannia 12/18/2000 02:37PM
RE: type xxi Takeo 12/18/2000 03:16PM
fallout? Tom Iwanski 12/18/2000 03:39PM
RE: type xxi kurt 12/18/2000 05:43PM
RE: type xxi Rainer Bruns 12/18/2000 03:40PM
RE: type xxi Steve Cooper 12/18/2000 04:54PM
RE: garbage? Antonio Veiga 12/18/2000 08:16PM
RE: garbage? Rick Mann 12/19/2000 07:58PM
RE: gaijin kurt 12/19/2000 11:47PM
XXI and the 300 U-boats SuperKraut 12/18/2000 09:41PM
Scary thought J-E 12/19/2000 01:27PM
RE: type xxi kurt 12/18/2000 05:41PM
RE: type xxi MCE 12/18/2000 06:00PM
RE: type xxi kurt 12/18/2000 05:55PM
You have missed the point SuperKraut 12/18/2000 09:30PM
invisible snorkels at the XXI Kurt 12/18/2000 11:23PM
XXI capabilities SuperKraut 12/19/2000 08:27PM
RE: invisible snorkels at the XXI Craig McLean 12/20/2000 03:19AM
Underwater speed and range SuperKraut 12/20/2000 09:39AM
Snorkels and The Bismarck Add On Fin Bonset 12/20/2000 01:07PM
Bismarck Fleet Add On Fin Bonset 12/20/2000 01:09PM
RE: Bismarck Fleet Add On Fin Bonset 12/20/2000 01:10PM
RE: type xxi Steve Cooper 12/19/2000 06:20PM
RE: type xxi Stewart 12/19/2000 07:29PM
Blair SuperKraut 12/19/2000 08:49PM
RE: Blair kurt 12/19/2000 11:40PM
RE: I meant 1950\'s kurt 12/19/2000 11:48PM
RE: Blair Jim, 12/20/2000 01:35AM
RE: mystery radar kurt 12/20/2000 10:10PM
Radar and snorkels SuperKraut 12/20/2000 09:09AM
Wilhelm Bauer Type XXI Rick Mann 12/20/2000 05:06PM
RE: Wilhelm Bauer Type XXI SuperKraut 12/21/2000 10:08AM
RE: Wilhelm Bauer Type XXI Rick Mann 12/25/2000 05:01PM
RE: Wilhelm Bauer Type XXI SuperKraut 12/28/2000 12:41AM


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