Re: [PSUBS-MAILIST] Yunk Yard Wars Submarine Building

[irox <irox@ix.netcom.com>]

Hi Brent,

there is a ton of info in the archives about propane tanks and why they do
not make good pressure vessels, as well as the problems of installing stiffiners
into a propane tank (you need to avoid a radial cut to open it and cut it 
length wise).

Cheers,
  Ian.


-----Original Message-----
>From: Brent Hartwig <brenthartwig@hotmail.com>
>Sent: Jul 21, 2008 3:25 PM
>To: PSUBSorg <personal_submersibles@psubs.org>
>Subject: [PSUBS-MAILIST] Yunk Yard Wars Submarine Building
>
>
>Can a reasonably safe basic submarine be built for under $2,000 US?   I suspect a lot of guys are mostly thinking about 1 ATM subs and not ambient and/or wet subs, of which tend to cost less. Some times far far less. 
> 
>Can a reasonably safe ambient or wet, oil drum submarine be designed and built? I believe there are lots of options. The Chinese oil drum submarine builder will likely put his sub in shallow water for testing and see he needs a lot more keel weight before he even gets into it. He can add more weight to the wheel assemblies and/or a keel of some sort below the hull. The RV Needlefish had the same basic metacenter problem, and Bill found that out without ever diving it.
> 
>How many people have died in 1 ATM and/or ambient propane tank sub? 
> 
> I have literature in my K-250 paperwork that has the George Kittredge saying that you can build your whole K-250 sub out of A-36 mild steel and be just fine. He did say how ever that A516 Gr 70 is a great upgrade. Here is the quote.
> 
>"You will find an apparent discrepancy between the steel listed on the plan (A-36) and the steel recommended in the building instructions (ASTM 516 Grade 70).
> 
>When the plans were approved by Lloyd's Register of Shipping in March of 1978, A-36 steel was acceptable. At about the same time, The American Society of Mechanical Engineers was promulgating their ANS1/ASME PVHO 1-1977 (Safety Standards for Pressure Vessels for Human Occupancy). In it, they dis-allowed the use of A-36, A-283 (Grades A, B, D) and A-515.
> 
>What does this mean to you? A-36, A-283, and A-515 steels are good quality steels. A516 Gr 70 is a superior steel for low temperatures. It has excellent notch toughness properties for cold weather operations. If there is any chance that you are going to want to have you K-250 classified by either the American Bureau Of Shipping of Lloyd's Register of Shipping, you should use A-516 Gr 70, but if you are just going to use your K-250 for recreational purposes do not worry about either A-36 or the A-285C. Probably the last bridge you drove over was constructed of A-36. The last sky scraper building you were in was probably constructed of A-36."
> 
>Designing a $2,000 US 1 ATM sub that anyone in the world could find the same materials for the same price, is not likely. When one has the need and/or desire to construct a inexpensive sub, it's not always about getting new products cheaply, but usually about found objects that are very cheap or even free. To build those same objects brand new would be in many cases very expensive.  I have two used, but solid nice 500 gallon propane tanks with half hemisphere heads that I got for free from a neighbor. Should I not use them for a 1 ATM sub because they are not made of new A-516,they have a little bit of rust on them, and they smell funny?  The heads are robot welded with three passes. Most of us can't weld even close to that good. Besides I would likely have to cut one end off to install the ribbing unless I cut the ribbing into three sections. Or if your going to install fairings and/or you are not worried about speed then install the ribbing in the outside.
> 
>One thing that this group needs to be reminded of from time to time, is that the synergy of experiences and combined brain power of this global group, is incredible, if not impeded. One person may post a half baked idea, of which will give one or more people an idea or two of how to make it a more and/or completely baked idea. A problem might put all of use and are friends, family, and acquantents to task, to solve.     So let if brew. 
> 
>Just because you have a valid proven point of why an idea in it's current configuration will not work, doesn't mean that after you post why you think the idea will not work, that other people will not be able to figure out how to solve that puzzle. We very much need group members to tell use why they think some thing will not work as presented, but if possible try to be part of the solution by posting other options you think will work and/or you think might need to be looked into to solve the problem you presented. Even if there is a chance they might turn out to be a dead end. 
> 
>This is a group of discovery.         Savor it. 
> 
>We are a think tank, that wants' to be in the world tank.
> 
>Stir the pot with a bigger egg beater, with more horse power if need be.
>
>Cheers,Brent Hartwig




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