[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PSUBS-MAILIST] Reserve buoyancy
Great idea. I had been wondering about that with regards to a WASP unit to
avoid blocking the view from the dome. If the fabric is bonded/retained to
the hull along a seam then you'd have predictable folding and
characteristics (underway) both above and below the surface.
A number of years ago I contacted the materials supplier for Avon & Zodiac.
Almost indestructable stuff. The tech has improved from 15 years ago I'm
sure. Don't know about the price, though.
Gordon (?) wrote an engineering book (~ Why Things Fail) a number of years
ago that stressed the value of using soft or flexible materials as tools
rather than being focused on rigid materials because of their "strength".
Trees/skyscrapers in the wind, etc.
Rick in Vancouver
==============================
----- Original Message -----
From: "Sean T. Stevenson" <cast55@telus.net>
To: <personal_submersibles@psubs.org>
Sent: Thursday, December 03, 2009 8:45 AM
Subject: Re: [PSUBS-MAILIST] Reserve buoyancy
> This suddenly made me think of something - and I'm sorry that I'm not at
> my own workstation right now or I would sketch it - but imagine if you
> will hard ballast tanks (saddle tanks), slung high under the weather
> deck, sized appropriately for the design waterline with tanks blown.
> These tanks would have a flat bottom instead of being faired into the
> hull, and attached to the underside of these tanks are hypalon buoyancy
> tubes which are ordinarily deflated (thus eliminating the extra mass of
> water to be moved, but adding some surface / form drag), but which may
> be inflated to increase the freeboard in specific circumstances, or, if
> appropriately sized, as a salvage measure.
>
> -Sean
>
>
> Alan James wrote:
> > Hi Mark,
> > Re the large ballast tanks, another thought is that the larger they are
> > the more drag, & inertia due to them being filled with water while
> > submerged. I'm not sure how much of a problem or extra drain on the
> > batteries this would be. Someone with experience might like to comment
> > on that.
> > Alan
> >
> > ----- Original Message ----- From: "F. Marc de Piolenc"
> > <piolenc@archivale.com>
> > To: "Personal Submersibles" <personal_submersibles@psubs.org>
> > Sent: Thursday, December 03, 2009 7:00 PM
> > Subject: [PSUBS-MAILIST] Reserve buoyancy
> >
> >
> >> I've been silently following the tender/reserve buoyancy discussion.
> >> As my primary interest is in salvage rather than sightseeing, I have
> >> assumed from the beginning that any sub that I build or am involved
> >> in building will follow safety criteria more like those of cruising
> >> Naval submarines than research subs. But now, reading the report of
> >> the salvage of the Alvin by the US Navy, I see that the allowances
> >> for research subs are inadequate.
> >>
> >> Aluminaut was selected for the salvage op because she was the most
> >> autonomous and robust of the submersibles available. After her first
> >> dive, when she spent several hours trying to insert the lifting
> >> toggle in Alvin's hatch, she surfaced with her batteries exhausted.
> >> It proved to be impossible to recharge her at sea, because the main
> >> hatch had to be kept open to allow hydrogen to escape, and when it
> >> was left open she shipped water! She had to be towed to sheltered
> >> water for repairs and a recharge. This is all the more remarkable
> >> because Aluminaut is the most seamanlike of all the research
> >> submersibles that I've actually seen.
> >>
> >> Battery vented into the crew space? No means of airing the boat
> >> without leaving the hatch open? I can understand not providing a
> >> separate snorkel or air-induction trunk - this is a deep diver, and
> >> every pressure-hull penetration is a potential failure point - but in
> >> that case the saddle tanks should have been made larger and some
> >> means of fitting a funnel over the main hatch to prevent water
> >> ingress should have been provided. And as for venting the battery
> >> into the crew compartment, ANY arrangement is preferable to one that
> >> exposes the crew to hydrogen, or worse - chlorine!
> >>
> >> http://www.archive.org/details/recoveryofdeepre00unit
> >>
> >> I assume that reluctance to add saddle tank volume in a personal sub
> >> is due to the need to trailer it home. If it exceeds maximum highway
> >> specs it must obtain a special movement permit every time it hits the
> >> road.
> >>
> >> Best,
> >> Marc
> >>
> >>
> >>
> >>
************************************************************************
> >>
************************************************************************
> >>
************************************************************************
> >> The personal submersibles mailing list complies with the US Federal
> >> CAN-SPAM Act of 2003. Your email address appears in our database
> >> because either you, or someone you know, requested you receive messages
> >> from our organization.
> >>
> >> If you want to be removed from this mailing list simply click on the
> >> link below or send a blank email message to:
> >> removeme-personal_submersibles@psubs.org
> >>
> >> Removal of your email address from this mailing list occurs by an
> >> automated process and should be complete within five minutes of
> >> our server receiving your request.
> >>
> >> PSUBS.ORG
> >> PO Box 53
> >> Weare, NH 03281
> >> 603-529-1100
> >>
************************************************************************
> >>
************************************************************************
> >>
************************************************************************
> >>
> >
> >
> >
> >
> > ************************************************************************
> > ************************************************************************
> > ************************************************************************
> > The personal submersibles mailing list complies with the US Federal
> > CAN-SPAM Act of 2003. Your email address appears in our database
> > because either you, or someone you know, requested you receive messages
> > from our organization.
> >
> > If you want to be removed from this mailing list simply click on the
> > link below or send a blank email message to:
> > removeme-personal_submersibles@psubs.org
> >
> > Removal of your email address from this mailing list occurs by an
> > automated process and should be complete within five minutes of
> > our server receiving your request.
> >
> > PSUBS.ORG
> > PO Box 53
> > Weare, NH 03281
> > 603-529-1100
> > ************************************************************************
> > ************************************************************************
> > ************************************************************************
> >
> >
> >
>
>
>
>
>
> ************************************************************************
> ************************************************************************
> ************************************************************************
> The personal submersibles mailing list complies with the US Federal
> CAN-SPAM Act of 2003. Your email address appears in our database
> because either you, or someone you know, requested you receive messages
> from our organization.
>
> If you want to be removed from this mailing list simply click on the
> link below or send a blank email message to:
> removeme-personal_submersibles@psubs.org
>
> Removal of your email address from this mailing list occurs by an
> automated process and should be complete within five minutes of
> our server receiving your request.
>
> PSUBS.ORG
> PO Box 53
> Weare, NH 03281
> 603-529-1100
> ************************************************************************
> ************************************************************************
> ************************************************************************
>
************************************************************************
************************************************************************
************************************************************************
The personal submersibles mailing list complies with the US Federal
CAN-SPAM Act of 2003. Your email address appears in our database
because either you, or someone you know, requested you receive messages
from our organization.
If you want to be removed from this mailing list simply click on the
link below or send a blank email message to:
removeme-personal_submersibles@psubs.org
Removal of your email address from this mailing list occurs by an
automated process and should be complete within five minutes of
our server receiving your request.
PSUBS.ORG
PO Box 53
Weare, NH 03281
603-529-1100
************************************************************************
************************************************************************
************************************************************************