Dealing with pirates

Sorry Guys we are here on a forum about piracy can i invite you to further concrete submarine discussion to the concrete submarine yacht - forum

Kindest Regards,
wellmer

 

concrete submarine hulls special concrete

BillyDoc
...more like a very dense ceramic than normal concrete... whow!!! This might be open a complete new horizon.

In my submarine yacht project - http://tolimared.com/submarine - i used normal concrete. This boat is designed to go some 300m down with a safety factor of 1/3 so might have a destruction depth of 900m - anyhow the weak point is not the hull made of normal concrete but the viewports. I discussed with carsten from euronaut that it would be a fine thing to get rid of viewports and replace them by camera system on a deep diving boat.

Deep diving is always the question HOW deep diving - i would estimate that a concrete sub with a hull still able to float (keep foam and gasoline flotation bodies away) could go to maybe 2000m.

Your special concrete could give us still floating spheres that could be able to reach ocean bottom at 97% of the planet.

Currently submarines that can reach average ocean bottom depths have spheres of steel, titanium, glass, of about 2m maximum diameter as passenger compartments - this is the limit of material handling - you can not build a 7m diamater sphere with 1m wall thickness in those materials -

BUT you could with your special concrete!

The limited comfort in a 2m sphere limits divetime to a view hours and depends on a mothership for deployment.

Your method could open the possibility of big autonomous submarines reaching ocean bottom - maybe a small step in concrete construction - a big step in ocean exploration...

Kindest Regards,
Wilfried Ellmer

 

Hi Everyone,

I hesitate to respond here as this IS the Pirate thread . . . maybe the administrator can move it later?

Marshmat,

You are quite right, the technique described above is similar to the vacuum infusion techniques used for fiberglass, etc . . . but with one very important difference. In those techniques a vacuum is used to “assist” the flow of resin through the material and is applied at the same time or shortly before resin infusion. The problem is that even though a very low vacuum may be applied externally, if the fibers are packed very densely the gases will not be entirely removed (and sometimes not even close) and air bubbles will accumulate in various odd places as the flow front traps and compacts these remaining gases. To avoid this problem extreme care has to be used to design the part and mold such that all gases are swept ahead of the flow front during infusion. Unfortunately, this is extremely difficult to do in practice, and a screw-up here can ruin the entire part. With the process I described above the gases are removed to an acceptable level before infusion (taking the time to do so), so the flow front geometry simply doesn't matter. It is truly mind-boggling how long it can take to really de-gas a tightly packed “geometry” like fiber or concrete particles.

Poida,

When I was experimenting with this technique I didn't use vibration at all, just an elastomeric “window” for compaction via atmospheric pressure. I wish I had thought of it, as it is a very good and obvious idea!

And the undesirable effect of using an elastomer is that unless the elastomeric material used is very flaccid, when the water is infused it will try to “rebound” thus making the internal space larger than it should be, thus also reducing the compaction. Another problem is that when the concrete is even slightly compacted it is quite rigid, thus making it difficult to “shape” in the mold. All of which has got me thinking . . .

If I were to construct a submarine hull, I would take this approach:

First I would construct an inner hull of metal, say aluminum, with a modest metal thickness. Around this inner hull, and at a spacing sufficient for the concrete hull, I would weld up a second metal hull. Since I have unlimited funds to use in my dreams I would make this outer metal hull out of Nickel/copper alloy and avoid some future bottom scraping. Both hulls only have to be strong enough to maintain their shape with the weight of concrete between them.

Assuming an oblong spheroid sort of shape, I would tilt the thing up so the long axis was vertical, and make an arrangement for a hopper to hold sufficient concrete for the hull, and a vacuum connection.

Then I would put the whole structure inside a large separate vacuum chamber, pull a vacuum on the entire works for a day or two, and while the vacuum was still being pulled (especially below the hopper outlet) open the hopper and allow the cement to drizzle down into the space between the metal hulls. Doing it this way should de-gas the stuff nicely! And while pouring in the cement, I would be vibrating the entire setup as much as possible as you suggest! I think that this would compact the material quite completely as there would be essentially no gases to hold the individual particles apart.

After the concrete was in place I would introduce water into the hopper, the inner hull, AND the vacuum chamber simultaneously so that it can infuse the concrete. I would do it this way to avoid a differential pressure on either the inner or outer metal hulls as much as possible since this could distort them. The inner hull could also have a matrix of very small holes over it's surface to allow the water to infuse through.

I think that when the concrete curred this would produce a very strong submarine hull with a convenient metal sheath! I haven't looked at thermal expansion for this approach, but there is always steel if this proves to be a problem.

Wellmer,

Unfortunately, this is not such an easy process to accomplish in the average home garage. On the other hand, if there was enough demand for such hulls the tooling required is where the money would go, for the vacuum chamber and pumps primarily, as the concrete and material for the inner and outer metal hulls would be fairly cheap. Does this sort of an approach sound like anything that would be economically feasible to you? Can you imagine applying such a technique to your designs?

BillyDoc

 

special concrete for deep diving submarine

Hello BillyDoc - i am well aware that your special concrete is not a process i would recommend for the guy that builds his personal submarine in a garage.

In a submarine yacht a depth of 300m (900feet) is enough - and you can do that with normal concrete which you can form in a garage under ACME conditions - Coral reefs and most of continent shelf is in reach.

The interest for superstrong concrete might come from submarines for deep diving that are going for things that are down in the abyss at 2000m and below. Could be scientific purpose, could be salvatage ... my design was oriented to yachting (http://tolimared.com/submarine) with big viewports and daylight in the submarine - not to deep diving -

Deep diving always means sphere hull shape for the pressure vessel - you could combine a seagoing streamline normal concrete outer hull with a series of superstrong spheres as inner pressure vessel. The problem is how to build such spheres - current metal and glass tecnology permits a maximum of 2m diameter - concrete could offer much bigger spheres... big enough for a autonomous deep diving sub wall thickness of >1m impossible to do in other materials - normal concrete would probably be limited to 1000-2000m - your superstrong concrete could go down maybe 5000 m or more.

- economically feasible - would be by far cheaper than any alternative i can think about...

Kindest Regards,
W.Ellmer

 

dont see any pirates objecting to the concrete conversation,,,,,,,,,,,,however you may wish to study my good friends walruss ,,or frost,,the density of thier heads is way way ,beyond that of any concrete known to man ,,,,,,,,,,just kidding,,,,,,,longliner

 

Wellmer and Billy Doc this is the pirate thread. You've pirated it, good work guys.

That's what piracy is all about!

Wellmer as a family yachting craft I was sceptical of it's marketing potential, obviously you will get a lot of interest as it is a fascinating project.

However with Billy Doc's sujestion of making a superstrong concrete and now capable of great depths I would say forget your low cost budget priced hobby sub. you've now moved into the multi million dollar submarine.

But it needs to be developed so that it can be very manouverable, fitted with robotic arms controlled from inside the sub. Uses could include, oil rig diving to take the place of traditional divers who can only spend a little time under water and then have to surface and go straight into decompression and get pumped full of drugs, underwater pipe inspections, as well as cables (cable joining robotics would be good), of course as you mentioned salvage, standard submarine rescue. If the navy made an escape hatch that suited an attachable door on your sub, it could transport submariners to safety. The British navy used a robot to cut the cables trapping the Russian sub. a manned sub would have done the job much quicker.

Another thing I was wondering, I assume you made the inside formwork in segments that could fit out of the front window.

Billy, with your super strong concrete did you use aggregate or just cement and sand? I can't remember if you mentioned it. With an aggregate there could be a problem with separation ie uneven distribution of aggregate, cement and sand if it is dropped over too far a distance as in long formwork as the sub would be.


Actually I have been thinking of the sub this evening as I have been mixing concrete for a special effect we are putting around our pool. Round pavers with small rocks cemented in between them. I know you didn't want to know this, but I thought I would tell you anyway.

Regards
Poida

 

Hey Poida, this Pirate Life ain't so bad! When do we get to the Lusty Wenches though?

You bring up a very good point about the aggregate. When I was experimenting with this stuff I did mix sand and cement together with no problem . . . but I wasn't dropping it through a vacuum either. You might think that exactly because it is a vacuum everything would fall at the same rate, but I'm not so sure of that. Another effect of a high vacuum is to evaporate anything that is remotely volatile off of any surfaces, which is very convenient with fibers because it cleans them nicely. (In fact, when I was working with fibers using a similar process I had a hell of a time coming up with a mold release that I couldn't bond to very nicely. That included things like wax and polyethylene. It was very awkward to mold something in a nice expensive mold only to find out you had just glued the mold into a single piece. And to further complicate the matter, most materials contain a great deal of "chemisorbed" volatiles that will out-gas for very long periods of time.) With ordinary concrete a fairly common "aggregate" used here is a bunch of polypropylene fibers about five cm long. These are just mixed right into the mix after it has been wetted out and serve the same function as rebar, that is they give the resultant product some good tensile properties. Poly will outgas like crazy in a vacuum, however.

So, I can imagine this stuff falling with little volumes of material suddenly deciding that they really want to phase change and be a gas . . . and jetting about like little balloons in the process. It might be random enough not to matter, and of course the whole mix could be heated and an attempt to degas it made before letting it through a hopper . . . which is to say that it would have to be tried to see what happens.

It would also be a good idea to be very careful of the type of larger aggregate used because of outgassing. In my experiments I used quartzite sand with no problem (I have a good supply on the local beach).

Yar Har and Shiver me Timbers, Matey!

BillyDoc

 

yeah Poida see they round pavers me handsome would they be right for fitting into a catty pult thingy for firing at them there idjits as hijacks good ANTI pirate threads?

there Jack and I was havin this yere argement 'bout wether t'would be bedder to have a ginormous gun to blow dem pirates eads off or to meekly give in to 'em when we gets pirated ourselves by a bunch of buildrs - shiver me timbers tis enought to make cap'n Teach put out his burning beard and become all respecable like!

Never thowt a respecible sailor like Billy doc would turn to piracy, how be 'ee billy me boy ain't heard you much around these parts laterly (with runs like this tis a good job too - bloody concrete bubbleheads indeed!)

And as a reminder please all of you the British Navy is, in future to be refered to by it's real name - the "Royal Navy" never a finer bunch of men sailed the 7 seas (not very big but by heck they are GOOD -Ok they were in my day, maybe not so much now but I won't be telling you who I nominate as the best at the moment!)

 

Hey Walruss

You appear to have a computer fault, cant tell a word you talking about.

 

Yeah Jack it's like watching a foreign movie, needs subtitles so we know what he's talking about.

And do apologise to Queen Liz. for me Walruss for getting the name of her Royal Navy wrong.

Can't call it the British Navy as there's probably no British people in it any more.

Wonder if there's any British people in the British Airforce then?

Ta Ta
Poida

 

Throw a jar of best acid avaliable that would eat through the hull and deck quickly... That would keep the pirate busy while u run for your life.

 

Jack naw mate having a brain malfunction, even I can't understand what I talking about (so what's new there then?)

Poida 'course it's got Brits in (most of em have run away to your Navy 'cos you have something called "ships", we ain't got none of them - they keeps running into insignificant rocks in the Pacific - Australia I think it was called, apparantly an old penal colony of ours, still in use too by the sound of it! Full of pirates or something beginning with "P"

 

The thing is folks walrus will actually talk like that, he's not putting it on.

If you ever go to this part of the world you will need a translator.

 

jack me hansom

Thankee for lettin the cat out of the bag, this talking proper was a real problem to I. had to keep checking the dictionarry for all them proper words.

Tis Sunday a'noon so back to the smoke and all the building stuff I pretends to be interested in durin the week, will insult 'ee more next friday!!

 

dont forget about me !,,,,,,,,longliner