Concrete submarine

[hoytedow]

At least black is the right color for a funereal urn for burial at sea.

[WestVanHan]

Well if he claims it was poured monolithically,I'd be curious if the pour was properly vibrated and how he did it.

A slip form on that is impossible.

Maybe he had a rotating form,and did it over a day or two but thats not good enough.

And I somehow doubt it was vibrated.

[hoytedow]

I wonder how many voids would show up on xray?

[Jimbo1490]

Originally Posted by hoytedow

I wonder how many voids would show up on xray?

It would be quite cheap to do an X-ray analysis; I know people right here locally that do both X-ray and ultrasonic NDT. I had them do my carbon mast that I built in the shop to look for big voids and de-lams (passed )

I think the way you get this guy to 'put up or shut up' is to demand an X-ray or ultrasound (the NDT guys can tell you which is best) work-up on the completed hull. It's so very cheap to get this done, probably in the range of $1000-$2000 USD(for the X-ray), that I would think that ANYONE involved in this project (including Mr Wellmer) would demand such testing be accomplished. Sensibly, it should have been undetaken the day after the thing was poured/cast/otherwise 'layed up' to prevent the potential waste of doing further work toward completion of a hull that was already doomed by a built-in fault.

Of course, Mr Wellmer must have thought of this already and has such test results on hand that he is not revealing, right?

Jimbo

[apex1]

What do you think?

If YOU would have to transport something from, say south America to north America, stealthy.
Would it make sense to do that in a sort of "diving, motorized container" with upwards looking windows? One could see patrol vessels at the surface.

I know, that is a dumb question, but those are the only ones suitable here.

Richard

[Knut Sand]

Originally Posted by MikeJohns

Knut

I see you did a little FEA, it would be interesting to add the aft bulkhead and then have a look where your maximum stresses occur. Be nice to know E of the material too otherwise strain will be out.

If we'd assume that the aft bulkhead is supposed to hold against surrounding pressure? I'd not even consider that one, If I understand you correctly; A circular internal wall subjected to pressure? That'll pop inside the hull like a champagne cork, a bit difficult to ignore too...

I don't have the E module of concrete loaded in, used cast iron, very little flexibility in that material too, brittle in a way that makes that material difficult to use in pressure vessels. (Do we have a sort of similarity here?).

I'll remind you all I said the study (post 349, page 25) was worth close to notthing, but still there was compression stress in the window "corners" (can a circular window have a corner? Eh well... ) was in the area of 80 MPa, that was 30 bar (300 m)

No safety factor of any kind at all! In that "study";
(How many "no's" is it possible to put into one line?)

Concrete properties uncertain, 80 MPa compression stength is not average off the shelf... normally I'd assume that approx 20 MPa, is valid suggestion, reduce by a factor of 4,5 to 6, minimum. If I use my "study" as a guidance then; max dept should be:
20/ 6 = 3,3 MPa Allowable (compression around the windows).
80/300 = 0,27 MPa/m
I.E:3,3/0,27 = 12,4 m allowable depth...

Double that depth, you have a FOS of 3, that'll make this a nogo when it involves the possibility for injuries (ok I'm a conservative socialist commie...).

74,2 m (12,4 x 6) is Bravo Yankee Echo....

Guess Bntii is closest so far?

When seeing the reinforcement, aft there, at the rudders, its not too much?, I visualize a slap of concreate break off in 45° shape inwards.... I've been wrong before.... I'd love to see the actual design drawings...Please...?

And Apex, I'll not place any bet on this. I'll buy you one if we cross paths, though.. Guess we'd have something to talk about....

And if I were in the USCG, seeing a suspicious thing... lying on the seabed, i'd pop a (tiny) grenade, just to see what is is (was).... (ok now I'm a conservative evil socialist commie...).

[gonzo]

I'll get my Dick Tracy X-ray glasses and go there to do a survey.

[Knut Sand]

Originally Posted by Submarine Tom

I believe somewhere on this forum, he claimed it was all one pour.

Collapse depth numbers people for the destructive test...?.................

bntii: 85 m

watson: 0 m

s-tom: 312m

bntii: 85 m

watson: 0 m

s-tom: 312m

KnutS: 74 m

hmm, Watson is more conservative than me?
Apex? pick a number...


About the chosen colour; Black? I'd go for yellow...

[hoytedow]

Originally Posted by apex1

What do you think?

If YOU would have to transport something from, say south America to north America, stealthy.
Would it make sense to do that in a sort of "diving, motorized container" with upwards looking windows? One could see patrol vessels at the surface.

I know, that is a dumb question, but those are the only ones suitable here.

Richard

Mr. W. Ellmer has found an excellent way to drown drug smugglers.

[Submarine Tom]

Apex, surprisingly, is down for 1200 m!

Perhaps it's a typo and he meant 1.200 m

Tom

[Submarine Tom]

bntii: 85 m

watson: 0 m

s-tom: 312 m

KnutS: 74 m

Apex: 1200 m

Starting to get spicey isn't it...!

[Knut Sand]

Originally Posted by Submarine Tom

Apex, surprisingly, is down for 1200 m!

Perhaps it's a typo and he meant 1.200 m

Tom

or in fact exactly 1200 ......... (mm)?

[apex1]

Originally Posted by Submarine Tom

Apex, surprisingly, is down for 1200 m!

Perhaps it's a typo and he meant 1.200 m

Tom

Of course I meant 1.200 meter (in Europe thats one thousand two hundred) but in the context only!

In a real test it will fail at about 10 - 30 meter already, at the trough hulls.
The whole coffin at maybe 50 - 70 meters.

[dskira]

Wellmer, when you leave a negative, sign it a least, don't be a coward.
Daniel

[rwatson]

Originally Posted by dskira

Wellmer, when you live a negative, sign it a least, don't be a coward.
Daniel

Ummm - you will need to translate that - what are you trying to say ????