Are all Volkswagens Bugs Joe? ;)' "Remember, the water doesn't care whats inside, the volume remains the same, therefore you need to be same weight as original if you build to original dimensions." Right, but the equipment can be lighter allowing for more weight to be added to the keel and/or drop weight(s) and what equipment that is used can be in many cases placed lower. The intake and exhaust systems in the conning tower can be lighter and/or removed all together for a all electric version. Also using a thinner A516 Gr 70 pressure hull then the original would change the metacentric height. http://www.rnsubmus.co.uk/submarines/biber.htm Brent From: joeperkel@hotmail.com To: personal_submersibles@psubs.org Subject: RE: [PSUBS-MAILIST] Restoring a Biber (or Beaver) midget submarine Date: Tue, 12 Aug 2008 17:34:13 +0000 Brent, No, no no! Not a look alike! :) If someone were to do this, it would be best to stay within the original design dimensions, why,...it would be a historically significant replica. that would be noteworthy, (see my post to Jens), just don't operate it looking for treasure! Otherwise a Volkswagon painted to look like a tank, is still a Bug!! "....Also since there would be no need for the WWII very heavy equipment inside that would change a lot as well......" Remember, the water doesn't care whats inside, the volume remains the same, therefore you need to be same weight as original if you build to original dimensions. Joe From: brenthartwig@hotmail.com To: personal_submersibles@psubs.org Subject: RE: [PSUBS-MAILIST] Restoring a Biber (or Beaver) midget submarine Date: Tue, 12 Aug 2008 10:03:01 -0700 Hello Joe, The front and rear MBT's can easily be enlarged with out changing the external look of the sub. Lighter yet stronger modern materials can be used in the conning tower. Also since there would be no need for the WWII very heavy equipment inside that would change a lot as well. Even if you didn't do that, the existing freeboard height the Biber's have is more then a lot of PSUB's I've seen, including mine. Look at the last picture on this link. http://www.channel4.com/science/microsites/S/salvage_squad/machines/sub/index.html#4 Small saddle tanks like on some of the Seehunds, could be added as well, if one wanted the added surface stability. The torpedo battery pods, could also be lowered a few inches, and change the height of the main pressure hull indents that receive them to reflect that change, to gain a better metacentric height. This wouldn't really change the look enough for most to notice. Brent From: joeperkel@hotmail.com To: personal_submersibles@psubs.org Subject: RE: [PSUBS-MAILIST] Restoring a Biber (or Beaver) midget submarine Date: Tue, 12 Aug 2008 10:56:23 +0000 Hi Brent, The issue with those two in particular is how they lie in the water with minuscule reserve buoyancy. Not conducive to safe open water ops any time the hatch is opened. Assuming historical accuracy in a replica, no amount of modernization would change that. Assuming a historically accurate Biber, .....well now gasoline in a sub? Replace with the tiny Yanmar and you still have a low lying narrow beam ship. Best then to up the size to what Kraka became. Not to mention UC3. Thanks Brent! Joe From: brenthartwig@hotmail.com To: personal_submersibles@psubs.org Subject: RE: [PSUBS-MAILIST] Restoring a Biber (or Beaver) midget submarine Date: Mon, 11 Aug 2008 23:05:55 -0700 Greetings Joe, I've been meaning to tell you how much I enjoyed looking at you new CAD work on your float plane replica. You could make a very nice scaled down RC plane off those assembly models. With regards to making a Biber and/or Seehund looking PSUB, if a person really wanted to design and construct one, I don't see any massive road blocks in making a safe one. We have so many material, processes, and equipment options now days. They are a pretty sleek hydrodynamic design when compared to many PSUBs and they can be configured so many different ways internally. There shape isn't really all that odd for a sub. I don't think that not knowing what the results of a weights and moments calcs, would be on ones first configuration efforts, shouldn't be a reason to not even try. I see so many guys with now successful PSUBS, that likely didn't do any real serious weights and moments calcs on there PSUB having to place a lot of lead and other things in different places when they first put there sub's in water to get them to work as desired. I would be interested to know what percentage of PSUB's had proper professional weights and moments calcs done on that subs design before it was finished, and what percentage of those are now reasonably functional subs. Ya I know, I'm a pain in the arz. I just don't throw in the towel on ideas because I can't know for sure how every thing will work out in the end design in advance. Yes a Biber and/or Seehund PSUB look alike sub would likely be more work then a basic modern PSUB design, and they might have some operational disadvantages when compared to a given PSUB. But like we talk about from time to time, are subs should be designed for what we want them to do. So in this case, we would want them to look like really scary cool WWII German Midget subs, that also work for a lot of different kinds of adventures. Then much later they them selves would likely be in a museum for many more to enjoy. Mine however would be placed in my live aboard submarines living room, as a fish tank for sharks. ;)' A balanced submarine has a midget sub attached on each side. Cheers, Brent Hartwig From: joeperkel@hotmail.com To: personal_submersibles@psubs.org Subject: RE: [PSUBS-MAILIST] Restoring a Biber (or Beaver) midget submarine Date: Mon, 11 Aug 2008 22:23:18 +0000 ".......but found many constraints and would have found more once he became involved with weight and balance along with stability calculations......." True, so true! I kept putting off weight and balance calcs despite the software capability. More than any other single source, I found Jay's input the most valuable in remaining on course for a viable design. A military replica PSUB is possible, just look at Kraka for U-boat influences but, a Biber, or Seehund (In my opinion) should be considered as museum display candidates for the very reasons Jay points out. The sea will never leave me. I am building after all,...a seaplane but, as you can see, I still keep tabs on what you guys are doing. I also found a way to dedicate my psub efforts on my website http://sopwith-baby.com/Project_Genesis_II.html Take care! Joe |