Concrete submarine

by cold joints you mean that the previous pour of concrete has set before new pour?

 

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

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

I wouldn't buy, one let alone go down in one, without seeing the numbers

on video of a monitor with a credible witness present.

bntii: 85 m

watson: 0 m

s-tom: 312m

 

Never was the black hull cast in one pour! Just see the odd marks the mould battens imprinted!
It has to be done in a "glide cast" or "creeping mould" method. That is definetively far above Ellmers knowledge and capabilities.

And I would bet 1200 meter!..:idea:
yes, yes seriously!

Or what do you expect Herr Wilfried Ellmer wil tell us, how the test performed?

 

Clear enough that the fins are pasted on.
These are the cuts where the fins will be build into hull:

 

Wilfried
This sounds like horribly a side quick step. For any validity it would be required that you identify the 'board'. Otherwise it appears as marketing speak for "I have no idea about this".


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.

However without modeling the steel in the composite you won't come any where near a decent FOS analysis. For this you want something like Strand.

If it’s standard concrete of course there is a difference in E between the coarser aggregate and the rest of the matrix, cracking occurs here as well and the cracks propagate with each stress cycle.

Wilfried is quite misleading when he looks at essentially static service conditions and extrapolates that to a high number of high stress cycles.

It also will take a detailed and accurate FEA to identify and correct the structural hot-spots. This should have been done long before any work started on the vessel. The professional board of advisors that Wilfried has hired will of course be aware of this and Wilfried can post their analysis for us, or he can email me their contact details and I'll ask them directly and discretely. Or since they are bound to be reading this they can contact me.............................I'm not holding my breath.

Otherwise this whole approach is a parody of proper design procedure and all we have from Wilfried in reply to very searching queries are marketing platitudes.

But before the engineering comes the whole concept of a slow dangerous environment cruising vessel. I strongly suspect the appeal will last up to the point where the novelty wears off of having a slow cumbersome vessel that can be fully submerged in shallow water.

Every other aspect of operation is fraught with disadvantages and dangers. Every time a very real threat is mentioned we are told it only apples to military submarines, with that attitude the Darwin awards look like they might find some more candidates.

I might be wrong, but I don't like the look of the whole operation from concept to implementation any more than several more vociferous detractors have pointed out.

 

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

 

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.

 

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

 

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

 

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...).

 

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

 

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...

 

northward bound

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

 

Apex, surprisingly, is down for 1200 m!

Perhaps it's a typo and he meant 1.200 m

Tom