sub build underway christmas 2011

not only posted here(look back to the first few pages) but on youtube-but they are now private --i got a huge response and it was heartbreaking having to call it quits for a while---so i let down my viewers--they(the vids) were boring anyway..but if you have this burning desire to view them ill send them to ya...

 

check out carl t fross- his book talks about alternative pv's He is the leading authority and i learned a lot from him...

 

In your research, did you find any fc or concrete sub that's been in service for any length of time?
What service life is your goal for yours?

 

Don't you hear the man, he's totally "empiricist" so he has no intention to make any math..

 

And the drawings from page 2

 

Oh, I would say the math all that 'empiricist' malarky was making fun of - like some solid engineering calculations on minor things like oooh ... displacement, material specs, detailed equipment layout and specification, and the like - . Oh, and that weak as dishwater 'hull design' - that's what math you havn't done!

Whats with the 'nemesis' ? - I have no axe to grind with you, just with all over the top 'know it all' ridiculous claims based on very little genuine calculation, and then getting upset when people actually ask for more info.

no you cant - I admit I got it wrong when I predicted this wouldnt go further than setup stage - it didnt even get past the 'unsupported hype' stage.

Success ???? hahahaha. I suppose getting it out of the shed is 'success' - hey, why dont you go and ask Wellmer for a good price ? The storage bill at the dockyard must be getting pretty horrific by now.

And as for "30 inches of wall thickness and the fact that the pressure of at depth will seal that concrete up like its in a vice" ... that takes the cake. What a load of twaddle! - Do yourself a favour and see one of those great U Boat films that shows what happens at a couple of hundred feet with a small leak, not a major crack in the concrete for over 5 metres.

 

I can't find more detailed drawings either. Or detailed specs.
Without drawings, specs, and numbers, what is there to talk about?
If it's empirical, either you succeed or you fail when it's launched.
Talk is a waste of time and energy if there is no data to discuss until we see video of the first trip, or don't.

 

I think the rates of linear expansion are something like 11.7 vs 12 and if I remember and those are measured in mm/c but I'd have to go look. I'm a general contractor and understand materials use and characteristics very well, thank you.

Here's my point since it just didn't seem to catch earlier

now your sub is built and resting at the surface, the sun is beating down on your hatch for gwod only knows how long. Your sealant is acting like a thermal break between the hatch and the concrete, which having a K rating is maintaining its thermal equilibrium nicely, however your hatch is expanding in the heat of the sun. Now I'd think you would have to make some accommodation for that expansion through the use of a little something called, "an expansion joint". That joint is going to have to allow for some reasonably significant movement and is also going to have to maintain a water tight, "interface" between the two materials. The real rub is that your gasket is going to be tightest at the surface and at some undetermined depth, but in between those two critical locations its not likely to be at its best

Just out of curiosity what material were you intending to use and given say a 1 meter hatch what was your intended gap to prevent this type of thermal expansion of the hatch material from cracking your hull ??????? Your gasket material will need to be structurally sound across the distance of this expected gap at whatever depth and yet be flexible enough to maintain contact at each surface, seems to me like that puts a lot of not just tensile stress on this magical sealant but also sheer at the contact surfaces, most sealants although they tend to do well with tensile stress dont hold up partiuclarly well under sheer. Just sayin.

Also how does that material hold up to cycling and have you tested that jointery design. or is that something that your willing to stake your life on.

seems reasonable that you'd want to do some materials testing in order to determine what stuff works best and last longest, also what shaped joint will hold your sealant choice best.

it was actually an honest question and I'm kinda surprised your so aggravated by it. Any even slightly dissimilar materials will respond accordingly given the varying conditions each part of the hull experiences. The thermal properties of the two materials are such that metal exposed to nice warm sunshine vs concrete exposed to nice cold water is going to react differently when you submerge. The concrete isn't going to move much and the metal is going to contract quite a bit.

Sooooooooo

do you have a plan to accommodate this movement or what ??????

I gotta go with Mr Watson on this one mate

your hatch is going to contract away from your through hull at a greater rate than the hull will compress and your going to end up taking a shower you might not survive.

If your really planing on doing this you'd be way better off listening to some constructive criticism cause concrete just doesn't seem like a very popular choice. Could be for a reason.

what I've noticed about BDnet is that you'll get all kinds of great help and a few smart asses if your actually looking to figure out how to do something right. But if your determined to do something wrong, well, help only lasts so long and then things tend to break down.

there's good advice going on here, listen to it. If your determined to build a sub and you have miles of cash, then at least start by switching materials to metal and go from there.

 

So using that example you will say again:
"go for it"

I think your post is an excellent example of why a little bit of engineering is required for any structure.

You state:
"Oil drums and electric power and a few batteries, better than the wooden sub made in America during the cival war I think"

This is what happens to a oil drum subjected to less than one atmosphere of pressure:

http://www.youtube.com/watch?v=Uy-SN5j1ogk

What that demonstrates is that the vessel will not even withstand 1 atm of pressure or submerging past say 10'
If the builder screws up and lets this vessels drift down to about swimming pool depth- he will die.
The quite remarkable and well engineered wood sub was capable of 20 meters depth or 3 atmospheres.

No one said it cannot be done..

Everyone has stated the anything built must be designed so that the material used, in the structure chosen, will meet the loads imposed.

These are the basic tenets of all engineering.
It does not matter one iota how one gains this understanding whether through formal education, experimentation or emulation of known practice.

What does matter is that this understanding is present.
In its absence; 'what you don't know',
Will quite literally kill you.

 

Bushnell's wooden submarine "Turtle" was used in the Revolutionary War, not the Civil War.
In this, as well as the rest of the thread, Tuggie shows deep ignorance and thundering arrogance, a charming combination and all too common in modern discourse on all subjects in this country.
One thing I have painfully learned better than anything else after 50 years of seagoing, professional small ship and boat building, extensive sailing on traditional vessels and much exposure to engineering for the sea is that 'you can't bull***t the ocean', and this is bull***t.
Show us something like well-thought out and executed drawings of the structure and annoying details.
If you can't draw it, you can't build it.
Prove me wrong, but I doubt you will.

 

I expect to get about 150 dives within 1 atm and about 50 of those dives below that cyclic fatigue being a factor --an s.w.f. of around 1:3...
no concrete subs in service -but there is always a frst...why does there need to be one already in service? all that matter sis a concrete -ferro-cement hull can work...

 

Watson-- it was a term of endearment...truly!

ive done my displacement calcs..i can post those too-the material- specs as well-etailed layouts are not mathematically involved exceprt is military subs. most of this sub is ballast and arrangment of it which can only be guessed at until it in the water then added to adjust in the water- omce again incorrect..i do my homework-juist cuz i like imperical evidence(which for those who dont know-menas previously done in most cases)...doesnt mean i dont do the math..or most of it-

yes watson--this is what happens under pressure--not that i intend to have my vessel with areas that needs sealing--but to use the trieste--it leakes on the surface but was closed up under pressure...thats how it works it the same idea that a hatch cannot be open and it alos get sealed up duee to the pressure presing down on the o-rings...its very simple.

Wil is a visionary--thats all there is to that story,,he is genius...sadly you dont see it that way because you listen to what others say too much...
no offense..

 

The drum was not re-inforced which is what ive been saying about steel..if it always happened like this then no sub ever would have been built--ive seen this vid many times--its due to the rpaid expansion of gases then the rapid colling of them the conatiner implodes at atm pressure...

 

Tugboat- you are arguing that a home builder may use empirical methods to determine how structures are be designed to handle loads.

Can you explain how you are intending to empirically determine if your design has sufficient strength?

 

youve not seen my drawings--i have all my calcs -most if them off rhino--
again ad nauseum--math will prove nothing other than on paper it may or may not work..thats the bottom line --your experience is "on the water" as is mine--so there is a big diff..sounds like you r taking it more personal than
i am... anyway its moot at this point im doinmg a tug build--wanna go see it?

I am studying naval arch right now through macnaughton..and it really is useless for submarien work unless its FEA...i say prove me wrong--the onus is on you to prove me wrong!! not me!