Concrete submarine

[Knut Sand]

Originally Posted by wellmer

I was delighted by the conclusion of the failure report on sleipner A (contributed by knut) that engineers did not properly understand the underlaying basics - there was sophisication in the methods, well paid egineering teams, but lack of basic understanding of the load case...

To understand properly the use of rebar, pretension, posttension, concrete quality and numbers that you need to put in for calculation, it is important to understand that tension loads and compression loads are very different forces with very different building strategies.

As most basic, in science we do simple experiments, to confirm or dismiss theories. The toilet paper rip-line theory belongs to the tension force behavior.

If you pull toilet paper it seperates - try to seperate it by pushing it - you will see that the theory is not that "valid" for the field it was presented here.

I personally was not too pleased with the Sleipner A.... The company I worked with supplied valves and hydraulic/ pneumatic control systems for that rig...ballast systems... I had inspected quite a lot of those valves around in Europe at the time, so I guess I was in the first row if "interviewed persons"? Found nothing though... But not a too pleasent experience, the thought of maybe, that I (peeeerrrrfuckt me...), had overlooked, missed something... I got away pretty easy though. Some load cases I do understand, concrete isnt one of them.

BUT; as an amatour, I would assume that concrete would behave at its best under compression, 2 MPa in tension is close to zero.77 MPa in compression is something. To achieve that, some sort of prestressing must be the "standard".

Windows in line; The toilet paper comparison, If we make the paper thicker, lets use 2 mm plastic sheet? A row of circular holes? If we pull apart, well have tension stress (I've used the word tensile, not sure if that's quite fitting, suddenly... Norwegian IS one of the major languages in this world... Så da snakker...Ok then...). It may (depending on the shape of the holes/ rip here zone) go apart along the holes. Proving the theory of max stress in the same line as the row of windows. Now; compression, lets push the same piece of plastic together? Where will it deflect?, along the same line.... Until the row of holes start to shift in the z-plane, there's ONLY compression in that sheet of plastic.
BUT when the row of holes start to move up/ down (let's assume up), along that same line, there will tension at the upper side (inside of the hull), and compression at the underside (outside of the hull). Any material with similar ability to withstand tension/ compression in a relatively similar way (steel), will have zero stress in the middle line if that cross section, using the material "both ways" to the max. Now a material with only 2 MPa in the ability to withstand tension, will not do.... , the zero stress line will be right under the surface.... And when that start to break, it'll snap pretty quickly...

And not unless some serios considerations is taken into account during the building process, (normally prestressing....?) it'll be an accident waiting for the opportunity...

Also with regard to prestressing; how shall that be controlled? During the expected life cycle? Galvanized? DC protection?

Waiting for some numbers/ material properties, still....

quote; "lack of basic understanding of the load case..." quote end...
Ok, that goes for me, but I guess I'm in a pretty crowded corner right there..

And; Dskira, Bntii, Submarine Tom, Apex... Is this your way of behaving yourself? You must've all been a nannyproblem when you were at the kindergarten.... I was not... (well come to think of it, got my first kiss there, then one of the bigger boys came dragging a chair, I was thinking "what's he gonna come dragging that chair around here for...?" Then I got to ride an ambulance, I learned a lot that day....I probably too could go for a problem, I think... but not sure, with you guys, I'm getting pretty sure...).

Pops my arse....

Knut,
come on bet with me.............

[wellmer]

Originally Posted by Knut Sand

...Some load cases I do understand, concrete isnt one of them...to achieve that, some sort of prestressing must be the "standard"...

..."lack of basic understanding of the load case..."...I guess I'm in a pretty crowded corner right there...

Yes, seems to me that "lack of load case understanding in a submerged concrete hull" is a crowded corner here - it does not come as a suprise - given the amount of "concrete submarine semesters" the people talking here have studied...and the willingness to read the offered "studies list" to aquire the knowledge required to understand. Seems that some are reading my material only with the intention to find a point to mob me, instead of finding answers and understand things...

As i said before i am not a static engineer, i am not a material scientist, i have listened carefully to some experts on my advisor board, so i believe i can understand "a little bit" of what is the basics - as a result of a "serious effort of understanding" i made in that field.

So what i say may not be laser sharp in detail but it should give a "general picture" of the very basics - here comes the info:

Concrete compression strength is not a fixed number i can give you - from the moment of pour, concrete starts to gain compression strength, civil engineers normally handle 5 day strenght, 28 day strength, (depends on country). There are studies that show that the concrete keeps gaining strength up to 250% even some 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. The right way is to read basics and understand the material and load case - then calculate - and make predictions, then do testing and look if prediction was right and the "underlying math and therories" makes any sense at all. It happens that sometimes it does'nt especially if you try to use sophisticated computer models without understanding the basics. (sleipner)

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.

Prestressing is not a measure to give concrete compression strength - i suggest you build 2 small model hulls, one pre-stressd, one not, and test them to destruction - from what you have said here, i am sure you will be VERY surprised by the results.

Rebar, stressed rebar, is a measure to take "strange forces" tension, flexion, torsion, shear forces, - you should do some model testing to get a clearer understanding of the magnitude of "strange forces" in hydrostatic loading.

A real world structure always needs to takes some amount of strange forces so you certainly will need to take care of strange forces.

Having a closer look to the picture you see that we are moving the sub hull over uneven terrain so that it is only supported in the middle of the hull at the moment of the photo - this brings A LOT of strange forces into the structure - there are few ships that can stand that kind of "one point load" in drydock. So you see somehow we have sucessfully taken care of the tension, flexion, torsion forces.

As always we do our testing - to make sure that the correspondent security factors are in place and the basic theories, building strategies, and practices, lead to the expected results.



You also can see that the prototype was transported by truck some 500km from tyrol to lake Atter. I would assume that there have been A LOT of strange forces at work during that trip.

So in general i would say the way we take care of those forces seems to be OK . Especially i would say that any catastrophic failure theory, or misdesign theory should be dismissed by the simple fact that there is obvious prove that we build and sail submarine yachts made of concrete for decades - and still live to do more of it ...

I agree with daniel, if this is "DREAMING" ... international firm,...shareholders.... successful launches... tested all tech aspects....30 years experience... the dreamers obviously know "how to dream".



As mentioned before, our interest in exposing to the e-mob, or explaining tech basics repeatedly to people that still have not yet read the studies on the "basic reading list" ( http://imulead.com/tolimared/concret...ne/anuncios/du ), proving invented claims we never made, proving the obvious, revealing details on the companies R&D, responding to kindergarten level insults, pointless failure and misdesign predictions... - is not very high...so this leaves conversation a bit dry ...

For me (and probably for any reasonable person listening ) any question that brings up a point, or can lead to a chat that makes sense, is answered already.
So i am out and leave the e-mobbers speaking with themselves. - (the serious guys please contact me off forum...)

Cheers,
Wil

[bntii]

Knut- I would be fascinated by a discussion of the engineering and design evolution of the subs build by Weller.
I do not believe such a discussion is possible as Wellmer is not forthcoming on any aspect of this project outside of the "...easy understandable concept part".

1) He has long presented that the engineering is straightforward and simple. A logical expression of the material known by any one who possesses knowledge of structural concrete work.

This is one of the cornerstones of his movement- the logical, accessible nature of this material in this application.

2) He has long presented claims about the depth his craft are capable of obtaining as an expression of this materials inherent strength.

He has never presented a synopsis of the above two ideals:
A clear presentation of straightforward design in concrete which supports his claims.

He is now claiming that the design is based on a proprietary process which he will not reveal.

This leaves the conversation somewhat dry.
The observers can only comment on what is visible:

-A roughly crafted reinforced concrete shell of known diameter and thickness, with rebar placed in the middle of the shell, and formed with a non-continuous pour.

-Claims by the builder that the shell can obtain over 1200 meters in depth.

-Claims by the builder that his only testing to date is achieving 4% of the above depth in another unrelated design.


Wellmer is presenting himself as:

"We see ourself as the motor, inventor, developer, of the concrete submarine movement"

May I suggest a starting point for a more productive discussion?

Perhaps Wellmer can provide a simple overview of the submarines he has built. These vessels are the only existing examples to demonstrate the viability of the "concrete submarine movement".

So Wellmer-

As a the designer and developer of this movement.

A overview of each of the submarines constructed to date.
Could you provide for each submarine:

-The design (including how the shell is constructed to exhibit this materials properties in this application)
-The performance attributes of each submarine.
-How each design proved the superiority of concrete as a hull material over other options, and how this example influenced the next vessel in the program.


.

[dskira]

The pressure hull is the most simplistic (not for Wellmer since he do know what it is even if he think he knows it) calculation you can do in any form of material.
The systems on a sub, represent the whole difficulties and the lenghtly design done by several people each one in his own specialties.
Concrete, steel, wood, even composite is not the problem and is not the concern.

The concern is when a liar try to get money for something he doesn't know the first thing about. And submarine are the most dangerous vessel you can find.

Posted by Wellmer:
Posted July 6 2007 at 7.27 in the webforum PSUBS.Org

"The by far cheapest way i found in my 30 years of submariner "

The guy is born 16.10.1962, in Hallstatt Austria. In 2007 when he wrote this piece of crap he was 45. So at age 15, after 4 years of medical school he went on submarine. So he started medical school at age 11!

This is what I call a cheater, a liar and a fake. As for the call for investor, we have an other name here.......................
In the old time they end up cover in tar with turquey feather glued on the body and shown to the whole population before being kicked out of the town

[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.

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

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