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What if the OKM had approved the Walter Submarine when he first mentioned the concept?

Discussion in 'What If - European Theater - Western Front & Atlan' started by Shadow Master, Mar 11, 2009.

  1. Sbiper

    Sbiper Member

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    Rossler is pretty much the bible, though there are several other books that support/illuminate Rossler's work, I'm in work right now so I'll post them later, off hand Freidman's 'US Submarines Since 1945' has some very interesting stuff in the chapter called 'The High Speed Submarine' which goes through the USN's early post war attempts to develop what we would now call AIP propulsion. The options were they selected were 1. Walter drive 2. Closed cycle diesel 3. High Pressure Steam Turbine (2 and 3 running off stored O2 underwater, atmospheric air while surfaced/snorting; technology developed for option 3 later appearing in 1960's USN DD power plants) and 4. Nuclear. This pretty much shows that in an operational submarine of that time frame closed sycle drives (non nuclear) were a rather unattractive option; the weight of the plant and oxidiser resulted in either a sub with reduced operational capability or one that was excesively large.

    It is interesting to read that even at this early stage nuclear power became increasingly attractive as it rapidly matured, though part of the attraction was that the USN designers had radically underestimated the weight and bulk of a sub nuclear plant. It was only when detailed design began for the 1st and later 2nd generations of SSN's that the USN realised that submarine nuclear power systems had different power scaling laws than conventional power plants i.e. nuclear systems suffer from a much higher 'fixed weight' penalty than conventional power plants.

    I'll also try and post a .pdf document I have about the Jap high speed designs (its a USN Intel document from the immediate post war, not paticularly good but the best source I've found so far for info on IJN high speed subs).

    In relation to high speeds, the 'Type XXI concept' of packing the hull with batteries and installing more powerfull moters along with streamiling the hull quickly brought conventional hulls up against their speed and control design limitations, even without research into exotic propulsion conventional lead acid battery subs would have needed a new hull form to fully expolit the Hp they now could generate underwater i.e. taking a conventional 'electrobbot' style diesel electric drive of the time and wraping a 'body of revolution' type hull around it would have given you 20knts at the 1 hour rate, while the same powerplant fitted into a 'streamlined hull' would give you 15/16kts tops, assuming that the displacement of the two designs remained roughly the same.

    There is an interesting power curve diagram in the book 'Albacore, forerunner of the future' that shows the Hp needed to drive various types of hulls at certain speeds; the Hp required to drive an 'ideal' body of revolution hull is vastly lower for any given speed than that of even the best conventional streamlined hull.

    Even since I read about Heinbergs work I've been fascinated as he seems to be the only possible way that the KM could have developed and deployed more advanced U-Boats before they did, without resorting to some sort of foreknowledge etc. which as I've said opens up a huge can of worms etc.

    Sbiper
     
  2. Sbiper

    Sbiper Member

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    Based on what I've read about the subject you would need a 'sea change' (pun intended) to get the KM and the Nazi's to make the expensive and intense investment in Sub technology to give them a proper fighting chance of defeating the allies at sea.

    First off the leadership of the KM were a highly conservative bunch, secondly Germany's naval design talent pool was small, along with a rather limited industrial base to support shipbuilding an thirdly and prehaps most importantly Hitler did not regard the UK as a potential enemy, up until mid 1938 France and the Soviet Union were seen as the main enemies. Fleet priorities were set out with this in mind, the Anglo German Naval Agreement of 1935 explicitly wedded the KM to a 'balanced fleet' concept with a limited U-Boat complement.

    To overturn the above obstacles would be to my mind a very difficult thing to acomplish IMHO.

    Sbiper.
     
  3. Sbiper

    Sbiper Member

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    Two good books are Submarine Design by Ulrich Gabler (he was a junior naval architect at the end of WW2 and post war he was the man prehaps most responsible for the 201 to 290 classes of submarine, the most sucessful post war western diesel electric designs) and Submarine Design and Development by Norman Friedman.

    Sbiper.
     

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