Technology and Operations  
This forum is for discussing technological & operational matters pertaining to U-boats. 
RE: technological differences?
Posted by: Tom Manson ()
Date: June 28, 2000 02:51AM

Les wrote:
"Why then the propensity towards hull shapes similar to surface vessels?"

Because prior to the Type XXI, submarines were not actually submarines, they were surface vessels with the ability to submerge for brief periods (i.e. they were submersibles, not submarines). Since they spent the vast majority of their time on the surface, it was only logical to design a hull shape which was more efficient on the surface. Prior to 1941, submarines usually dove only to evade a counterattack. They would sometimes dive to make a submerged attack, but it was more common to attack on the surface. For the rare occassions when they submerged, they could put up with a noisier and less hydrodynamic hull shape.
Again, since they were designed as surface warships before WWII, the submarines were given a deck gun (or two) plus some anti-aircraft guns. To accommodate the guns, flat and wide decking and/or platforms around the gun mounts, railings, ready ammo lockers, etc. had to be added. A boat which spends most of its time on the surface needs other external features such as a wide open bridge and the flashing around it to reduce the effects of waves crashing against the conning tower. You also end up with net cutters, jumping wire supports, bollards, cleats, topside torpedo canisters on U-boats, deck planking, etc.
When you design a true submarine which will spend most of its life under water, you design a hull shape which is hydrodynamically effficient underwater even if it is less efficient on the surface since you won't spend much time there. Since you will not be fighting aircraft, you don't need anti-aircraft guns with all of their platforms and gun shields. Since the crew will not be walking around outside of the pressure hull, there is no need for a flat deck or hand rails.
By designing a boat with great underwater endurance, you change the fundamental purpose of the boat from a diving torpedo boat to a submarine. Simply adding a schnorchel to an older design of U-boat (Type VII or Type IX) to extend its underwater endurance helps, but it still leaves the vessel dependant on the surface for a significant portion of its day if it intends to cover any decent distances.

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Subject Written By Posted
technological differences? Les 06/27/2000 01:49AM
RE: technological differences? Ted Armstrong 06/27/2000 06:46AM
RE: technological differences? Mike Sung 06/27/2000 12:47PM
RE: technological differences? Rainer Bruns 06/27/2000 03:27PM
RE: technological differences? rabbit 06/27/2000 05:02PM
RE: technological differences? Rainer Bruns 06/27/2000 06:46PM
RE: technological differences? Les 06/27/2000 10:02PM
RE: technological differences? Joe 06/28/2000 06:14AM
RE: technological differences? Rainer Bruns 06/28/2000 03:31PM
RE: technological differences? Joe 06/29/2000 07:20AM
RE: technological differences? Rainer Bruns 06/29/2000 02:01PM
RE: technological differences? Joe 06/30/2000 05:41AM
RE: technological differences? - RN? Rainer Bruns 06/30/2000 01:06PM
RE:measures and countermeasures. Don Dirst 06/30/2000 07:29PM
RE:measures and countermeasures. Tom Manson 07/01/2000 02:14AM
RE:measures and countermeasures. Don Dirst 07/01/2000 11:12AM
RE:measures and countermeasures. Rainer Bruns 07/01/2000 02:29AM
RE:measures and countermeasures. Rainer Bruns 07/01/2000 03:20AM
RE: technological differences? - RN? Rainer Bruns 06/30/2000 01:08PM
RE: technological differences? - RN? Rainer Bruns 06/30/2000 01:09PM
RE:measures and countermeasures. Joe 07/01/2000 12:43AM
RE:measures and countermeasures. Les 07/01/2000 01:20AM
RE: technological differences? Les 06/29/2000 02:39AM
RE: technological differences? Tom Manson 06/28/2000 02:51AM
RE: technological differences? Rainer Bruns 06/28/2000 03:27AM
RE: technological differences? Rick Mann 06/29/2000 12:51AM
RE: technological differences? - RN? Andrew Hetherington 06/30/2000 10:25AM
RE: technological differences? - RN? Rainer Bruns 06/30/2000 01:14PM
RE: technological differences? - RN? Robert Eno 06/30/2000 03:48PM
RE: The more things change...ya know the rest... rabbit 06/30/2000 05:43PM
RE:measures and countermeasures. Tom Manson 07/01/2000 02:31AM
RE:measures and countermeasures. Old Salt - Once There 06/30/2000 11:51PM
RE:single screw maneuverability AL Wellman 07/01/2000 04:16PM
CO2 Filters DS 07/04/2000 03:15AM


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