Concrete submarine

[bntii]

Originally Posted by wellmer

Concrete compression strength is not a fixed number - from the moment of pour, concrete starts to gain compression strength, civil engineers normally handle 5 day strenght, 28 day strength, (depends on country) but there are studies that show that the concrete keeps gaining strength up to 250% decades after the last worker leaved the building site. This is why i will not give you a single number for the concrete quality - to know what numbers you put into ANY calculation you need to have that kind of "basic understanding" of the material and its properties.

A civil engineer given the indication "high quality concrete" knows what range of numbers in what timeline, for what load case, he has to calculate with. Basic concrete engineering books are full of orientation on that.

[/IMG]

You are stating the obvious.
All materials exhibit a range of properties based on the grade used.

What type of concrete are YOU using?
Specifically. Mix and methodology.

This is the only manner in which you can state the range of properties your hulls will exhibit.

[Submarine Tom]

Blah, blah, blah, it will go on forever.

Willy, put an end to it. Video tape a destructive test of your claims.

Show what depth your wonder hull can achieve before failure.

Catastrophic failure. The proof is in the pudding. Time to put your money

where your mouth is, do the test and show the results. I wouldn't buy one

without this test.

So, are you willing or are you just talk?

Remember: "Talk's cheap until you get the bill!"

Tom

[gonzo]

I think we should organize a tourand all go to see the maiden voyage.
As she submerges, gracefully or not, with Willy inside, we all raise our margaritas or beers and cheer. There will be bets placed on the depth at which the sub will fail and Willy will get crushed.

[M-Sasha]

Interesting read here really. 29 pages to show us that this wellmer bum is unable to answer 1 question.

1
question.
only 1

which quality of concrete are u using Herr Wilfried Ellmer?


But he was able to put his pictures up 25 times and to fill half of a book with drivel.

You give him a free advertisement page here (and he is not clever enough to understand the effect).

Interesting read here really.
Sasha

[apex1]

Originally Posted by gonzo

I think we should organize a tourand all go to see the maiden voyage.
As she submerges, gracefully or not, with Willy inside, we all raise our margaritas or beers and cheer. There will be bets placed on the depth at which the sub will fail and Willy will get crushed.

I´ll pay the Beer!

Champagner if the last case mentioned comes true!

[Submarine Tom]

The proof is in the pudding, drop her down, down, down and see where she

collapses.

Hey, that gives me an idea: lets places bets on her failure depth.

I'm going to say 91 meters for the first leak, and 312 meters for

catastrophic failure, implosion, instantaneous collapse.

Tom

[bntii]

I give it destruction at 85 meters (I think this is too generous).

[rwatson]

You are all way too generous - I would put money on it never being even launched !!

I remember a story about a group of guys who wanted to repeat the Kon Tiki raft experiment across the Pacific. The Columbian Navy wouldnt even let them launch the raft.

They have been bitten too many times by expensive rescue attempts by non-insurable adventurers.

Who would want 200 tonnes of non-insurable concrete washing around the harbour, let alone busy shipping lanes with some of the most treacherous currents in the world ?

[Jenny Giles]

Originally Posted by Submarine Tom

The proof is in the pudding, drop her down, down, down and see where she

collapses.

Hey, that gives me an idea: lets places bets on her failure depth.

I'm going to say 91 meters for the first leak, and 312 meters for

catastrophic failure, implosion, instantaneous collapse.

Tom

I'm not sure how tall the builder is, but I'd say total failure occurred about 1.6m above sea level.

[WestVanHan]

I searched this site for cold joints,and none came up.

Have experience with monolithic concrete structures,and there must be be no cold joints except for at the foundation.

Ferroboats need to be built with no cold joints,and they will give you time to abandon ship if need be.
A sub-about .1 of a second

Looking at the pix,I wonder how many there are.

Just look at the pix closely,you can see how roughly it was builtwith what appears to be slabs they jammed in.

No thanks

[kerosene]

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

[Submarine Tom]

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

[apex1]

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...?

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!..
yes, yes seriously!

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

[bntii]

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

[MikeJohns]

Originally Posted by wellmer

........... i am not structural scientist but i hear from my advisor board that a "broad discussion" of "structural issues and details" with external experts should not be necessary..................

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.