But where is the real advantage of the design? You still need to have a
rather elaborate framework of steel.
If it's the outward appearance your trying to customize, you can do that
with fiberglass
fairings.
Remember, a sub has to replace it's weight in water so the weight savings
with fiberglass will have to be offset with lead or steel or something
making your sub as heavy as an all steel design.
All I see is, your trading some of the smell of welding for the smell of
fiberglass resin. And also trading a long proven material for one not quite
as proven in the sub world.
Dan H.
----- Original Message -----
From: "Mark Roberts - Harbortronics" <
Mark@Harbortronics.com>
To: <
personal_submersibles@psubs.org>
Sent: Saturday, January 27, 2007 9:59 PM
Subject: Re: [
PSUBS-MAILIST] Fiberglass Hull
>I was just thinking something long those lines too, as I arrived home
>
tonite.... of course the framework will have to be sized to hold all of
>the stresses, but it could be done. The construction process could be
>simplified quite nicely, and
retro-fits would be so much easier.
>
> ----- Original Message -----
> From: "Charles Perkins" <
chuck@memetech.com>
> To: <
personal_submersibles@psubs.org>
> Sent: Saturday, January 27, 2007 12:19 PM
> Subject: Re: [
PSUBS-MAILIST] Fiberglass Hull
>
>
>>
>> On Jan 27, 2007, at 10:37 AM, Mark Roberts - Harbortronics wrote:
>>
>>> One guy per the link points out a very important thing with regards to
>>> fibers.... they can be very strong in tension, but have effectively no
>>> compressive strength. To my mind, that's a show stopper right there.
>>>
>>
>>
>> A show changer, true... but not necessarily a show stopper. All one has
>> to do is put the casing of the pressure vessel under tension, rather
>> than compression.
>>
>> How?
>>
>> As a thought experiment, imagine a soccer ball. Let's replace the seams
>> with steal beams, and the skin with fiberglass... but allow the
>> fiberglass to bow inwards. The fiberglass under tension will transmit
>> the compressive force to the steel framework which can resist it under
>> compression and bending forces.
>>
>> One could make a cylinder similarly... take a hexagonal lattice, roll it
>> up, etc.
>>
>> Chuck
>>
>>
>>
>>
>>>
>>> ----- Original Message -----
>>> From: Brent
Hartwig
>>> To:
personal_submersibles@psubs.org
>>> Sent: Saturday, January 27, 2007 4:34 AM
>>> Subject: RE: [
PSUBS-MAILIST] Fiberglass Hull
>>>
>>> Doug,
>>>
>>> I'm not qualified to
answere your questions about fiberglass composite
>>> sub hulls under external pressure, but here is a interesting
thred
>>> about just that sort of thing. Here is the link and a small quote from
>>> the discussion that has the most meat in it.
>>>
>>>
http://www.eng-tips.com/viewthread.cfm?qid=174497&page=1
>>>
>>> "Spend some time looking through
ASME III (Unfired Pressure Vessels)
>>> for vessels under external pressure. And keep in mind that if you
>>> intend to operate at 100
ft (~45 psi) that you'll want a hefty margin
>>> against any kind of pressure boundary buckling failure. Think in terms
>>> of emergency recovery time from a depth overshoot if you experience
>>> horizontal control plane malfunction while descending at some speed and
>>> down angle when nearly at your maximum operating depth.
>>>
>>> I may be able to find a more specific
ASME reference for you, but for a
>>> number of reasons I don't think I can provide any hints as regards a
>>> design collapse depth, so you're on your own there.
>>>
>>>
>>> Norm
>>>
arto (Mechanical)
>>> 12 Jan 07 9:46
>>> also look under
ASME PVHO (Human occupancy) & Sec. X {fiber reinforced
>>> plastic) pressure vessel codes"
>>>
>>> end quote
>>>
>>> In the past I saw a web site for a deep diving live aboard submarine
>>> project called the Neptune. They were working on a design for a carbon
>>> fiber pressure hull that they claimed could be used down to 6000
>>> meters. The web site
waswww.
neptunesubmarines.com but it's a dead link
>>> now. I was put onto this site originally by a web site for the
Perendev
>>> magnetic motor. At one time I thought it might be a great motor for
>>> subs in general but there is some serious greed problems with the owner
>>> of the company. Neptune Submarines were wanting to put the
Perendev
>>> magnetic motor in there live aboard submarine to replace a nuclear type
>>> power source. Maybe someone here knows what happened to this Neptune
>>> Submarines group out of Switzerland? Here is a
pic of there submarine
>>> design.
>>>
>>>
http://img224.imageshack.us/img224/7608/24243158bk0.jpg
>>>
>>> Regards
>>>
>>> Brent
>>>
>>>
>>>
>>>
>>>
>>> From:
djackson99@aol.com
>>> Reply-To:
personal_submersibles@psubs.org
>>> To:
personal_submersibles@psubs.org
>>> Subject: [
PSUBS-MAILIST] Fiberglass Hull
>>> Date: Fri, 26 Jan 2007 00:35:40 -0500
>>>
>>> I know it's an old to
pic but I have mostly ignored the previous post
>>> regarding fiberglass because I never thought I was going to give it a
>>> second thought. ...wrong again.
>>>
>>> 1) Did anyone ever come up with a way to calculate even a ball-park
>>> working depth given all, or at lease some of the variables for
>>> fiberglass construction? If so can you point me in that direction?
>>>
>>> 2) I know that the externally loaded working psi for a non- reinforced
>>> cylinder is lower than it's internal working psi. That makes even
>>> more scene to me when thinking about the alignment and tensile strength
>>> of glass or carbon fibers compared to their compression strength.
>>> However it seems that there would be a ratio that could be used to
>>> estimate the reduction in loading ability. Would that be true? For
>>> example if pipe section is rated for 1000psi, could it's external load
>>> psi rating be stated as x% lower, say 20% lower, based on the type of
>>> material?
>>>
>>> Thanks --Doug J
>>>
>>>
>>>
>>>
>>> Check out the new AOL. Most comprehensive set of free safety and
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