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Re: [PSUBS-MAILIST] concrete submarine
Hmm - you can use the cabin inside even as ballastwatertank - you need
no other ballastwater tank .. and get a enormus freebord..
On the surface you can drive first in a dry compartment to the dive
place.. than flodded the cabin.. and the boat dive..
I like the idear..
The only problem you get - maybe this boats design gets to heavy..
..maybe you have to use light material for everything.
Carsten
Michael Edwards schrieb:
>
> Hello Wilfried:
>
> I do want to pressurize this hull, only with water in it. Less weight to sink
> the boat is less weight to pull on a trailer.
>
> I see this as a mobile diving decompression chamber, to maximize my
> bottom time. Yes, I do want to come and go out of the sub on the bottom.
>
> No doubt a "normal" wet sub would be easier, I'm just looking for a
> way to extend productive time underwater.
>
> Are you saying the 5 cm is the minimum wall thickness for this type of
> construction? If so what size rebar and spacing would you suggest?
>
> Do you have any picture of your small sub?
>
> I'm still wondering how you got such a fair hull, inside and out. I'm guessing
> you had a double mold, inside and out? I can't understand you you managed this.
> Mudding ferrocement yes, but not as a single cast piece.
> Would you share the secret here?
>
> My concern with corrosion is, it seems like concrete fails from the inside
> out with the rebar swelling from corrosion. Isn't normal cement hydrophilic?
> A poor water barrier?
>
> I'm very comfortable with steel, wood, fiberglass marine construction, but as
> you can tell I'm very new to concrete. I am planning an a much larger boat, but
> need to explore this material on a smaller scale to gain confidence and
> knowledge.
> I believe your concrete pressure hull has tremendous potential.
>
> Thanks for your patience with all these questions.
>
> Best regards
>
> Michael
>
> diagroto@ibague.cetcol.net.co wrote:
>
> > Hello Michael,
> > Would not use concrete as material for a wet sub.
> > Concrete works fine with wall thickness above 5cm (steel is protected-bringing
> > concrete into form is easy) - i would do a nice wet sub (prone position
> > floating) with acrylic and glass fiber materials. Or as a steel or alu cage
> > with textile coating. (similar to airplanes)
> > No need for extra protection of steel in a good built concrete wall. Steel in
> > concrete is by far better protected than steel in a steel hull where only
> > protection against seawater is paint. Do paint over concrete is dobble save.
> >
> > Greetings
> > Wilfried
> >
> > Mensaje citado por: Michael Edwards <me@sustainkauai.org>:
> >
> > > Greetings Wilfried:
> > >
> > > Thanks for the reply!
> > >
> > > Yes, I understand the size/weight issues. A am exploring the idea of a
> > > pressurized,
> > > wet sub.
> > > The prone position is very uncomfortable, dry in gravity, but very
> > > doable floating.
> > >
> > > I've spent thousand of hours underwater in this position. I don't need
> > > much over 2
> > > hours duration.
> > > My goal is to keep the trailer weight under 3 tons.
> > >
> > > Any thoughts about using a high fly ash content to keep sea water out of
> > > the
> > > concrete,
> > > and using galvanized or stainless to deal with corrosion?
> > >
> > > Best regards
> > >
> > > Michael
> > >
> > >
> > > diagroto@ibague.cetcol.net.co wrote:
> > >
> > > > Hello Michael,
> > > >
> > > > Yes, that is my approach too.
> > > > If you did a couple of tanks and test objects for pressure tests you
> > > will be
> > > > familiar enough with the material to make a sub that works.
> > > > My first was very small 2m long 70 cm diameter - 800kg - trailerabel
> > > (concrete)
> > > > BUT - you need a certain size to be comfortable enough inside to have
> > > a several
> > > > hours dive. As discussed by carsten it will be hard to combine
> > > trailerable
> > > > (small and light weight) with comfortable (certain space).
> > > > Subs are "heavy machines" by nature (below flotability) this means 1m
> > > cubic room
> > > > (very little to be comfortable)is 1 ton trailer weight (heavy for
> > > trailer).
> > > > So i ended up with a 9m 20ton sub comfortable inside, but far from
> > > trailerable.
> > > > If you need a real trailerable sub you might go for a wet sub only.
> > > >
> > > > see:
> > > > http://imulead.com/sub.html
> > > >
> > > > Greetings
> > > >
> > > > Wilfried
> > > >
> > > > Mensaje citado por: Michael Edwards <me@sustainkauai.org>:
> > > >
> > > > > Greeting Subers, and hello Wilfried:
> > > > >
> > > > > I am very interested in concrete submarine technologies.
> > > > >
> > > > > I retired from 30+ years commercial diving and running ships and
> > > now
> > > > > live in
> > > > > Hawaii.
> > > > > Bad for manufacturing but good diving ;-)
> > > > >
> > > > > I will be using concrete construction for a number of projects at
> > > our
> > > > > farm, water
> > > > > tanks,
> > > > > and buildings so why not build a sub?
> > > > >
> > > > > I am planning first to build a one-man micro sub. It needs to be
> > > > > trailerable.
> > > > > It would be nice to have something the tiger sharks here can't bite
> > > in
> > > > > half.
> > > > >
> > > > > Thanks for hosting this forum!
> > > > >
> > > > > Best regards
> > > > >
> > > > > Michael Edwards
> > > > >
> > > > >
> > >