Home Forums Research Engineering MINI-BERGSTEAD Model – 1/24 scale

This topic contains 78 replies, has 13 voices, and was last updated by  shredder7753 4 years, 1 month ago.

Viewing 15 posts - 31 through 45 (of 79 total)
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• #15004

elspru
Participant

ummm, I’d love to check your math, but it’s too confusing since you use a mix of metric and imperial measurements, I’d suggest you stick to metric, since it’s more logical and easier to work with for a variety of scales and conversions.

I’ll redo them for you:

volume 62cm*12cm*62cm * 1000kg/m^3 = 46.128kg (displacement)

(62cm*1.5cm*23cm*4+62.5cm*62.5cm*1.5cm) * 2400kg/m^3 = 34.5969 kg (weight)

46kg-34kg = (62cm*62cm* x cm) * 1000kg/m^3 where x = 3.12cm (freeboard)

So while ideally it should float, it’ll only have 3cm of freeboard, a small wavelet could swamp it.

Typically I like to have the weight less than 50% of displacement.

Also btw with the concrete falling apart, there are 2 reasons,

#1 you have to wait for it to cure, usually at least a few days,

#2 in my experience without internal reinforcement concrete crumbles, and has catastrophic failures easily.

Even if you get rebar/mesh, you can still keep your boxy design,

simply lay the rebar so it meets at the corners,

then make square lashings at the corners to hold them together.

calm aware desire choice love express intuit move

#15008

georgeberz
Participant

An eggshell though thin is very strong because of the curve

there is no rebar in it

question is how do you make a large concrete egg that is hollow in the middle in a SINGLE casting so you have no cold joints?

or a ball for that matter

George – http://OutpostAlpha.com

#15010

Anonymous

while I appreciate your imagination and design ambition, georgeberz, I think that for the time being the cost of producing an egg-form or geodesic dome form in a single mold would not out-perform a traditional concrete pour strengthened by rebar or other sub-structural enhancements. Not to say it would not be very strong itself, but just that the costs would make it less effective than other methods.

You could eventually make one egg/geodesic dome form for the price of a dozen traditional structures, simply due to the fact that traditional methods have already been perfected. (no real math in that statement, just making a point about cost/benefits for today’s world)

#15013

shredder7753
Participant

if u guys wanta talk eggs and spheres check out one one of Ellmer’s threads. he has experience with that. as far as my conceptual design goes, go comment on one of my other threads. this thread is purely for discussion and documentation of the implementation of my design which i already spent months on here talking about. thank u.

____________

My Work II

“Leadership and do-ership are not the same thing”

#15015

shredder7753
Participant

she’s water tight and almost ready to rock. i wish the hurricane was just 2 weeks later. i would have loved to test the submersion in a real hurricane. it turns out i might not have needed the metal straps to hold the broken piece. but i’ll never get em off now because the adhesive in that caulk tube is literally stronger than concrete!

____________

My Work II

“Leadership and do-ership are not the same thing”

#15017

georgeberz
Participant

How soon till it goes in the pool?

#15018

shredder7753
Participant

georgeberz wrote:

How soon till it goes in the pool?

im thinkin monday, if not tomorrow

____________

My Work II

“Leadership and do-ership are not the same thing”

#15021

georgeberz
Participant

awesome, keep us posted!

#15026

shredder7753
Participant

i am SOOO glad i didnt make the 1/12 scale model first. but im happy with this one.

here’s a quick video in the pool!

____________

My Work II

“Leadership and do-ership are not the same thing”

#15027

elspru
Participant

georgeberz wrote:

An eggshell though thin is very strong because of the curve

there is no rebar in it

question is how do you make a large concrete egg that is hollow in the middle in a SINGLE casting so you have no cold joints?

or a ball for that matter

George – http://OutpostAlpha.com

I made some egg-shaped boats by applying plaster onto a sand-mold, tested them in bathtub with bunny passengers.

One of the issues, is that it doesn’t scale well, and requires very thick walls for it to not crack in half.

For instance sometimes I’d pick up the shell by the freeboard, and didn’t give it enough support on the bottom, then a large chunk would chip off. Also if I had over-applied cement and I tried to chip it off, it could crack the whole boat.

Where as with the ferrocement dinghy, when adding on the cover, I beat the rims with a hammer, and it only chipped off the top portion which I was aiming for, the rest to the hull stayed intact.

shredder7753 wrote:

she’s water tight and almost ready to rock. i wish the hurricane was just 2 weeks later. i would have loved to test the submersion in a real hurricane. it turns out i might not have needed the metal straps to hold the broken piece. but i’ll never get em off now because the adhesive in that caulk tube is literally stronger than concrete!

____________

My Work II

“Leadership and do-ership are not the same thing”

What is the adhesive caulking you’re using?

calm aware desire choice love express intuit move

[/quote]

calm aware desire choice love express intuit move

#15028

OCEANOPOLIS
Participant

there to many portholes openings and too close to the actual waterline? Unless there will be real portholes there that you can shut watertight, then water will flood the interior with every wave that his the hull,….same thing with the cut off in the back of the structure. Other than that, it looks good.

#15029

Anonymous

Ocean, you must not have read some of the earlier posts about the structure – thats fine, I do the same thing on plenty fo the longer threads.

This 1/24th model is not a perfect representation of a full scale product. The “port holes” will be filled with static windows before he begins with the submersion tests. The cut is actually the front of the structure rather than the back, and will be where the staircase is mounted. The staircase will be flushed with the roof as well. All of this plus the final skim coats and some sealant will ensure the entire structure is water tight, as a berg will need to be able to make itself given the submversive nature of the structure.

I think I covered all the bases, Rich. Correct me if Im wrong.

#15030

georgeberz wrote:
….how do you make a large concrete egg that is hollow in the middle….

can only tell you that it can be done, it has been done on small and large scale, – can not tell you how – as giving how to do instructions must be avoided due to…(link)

We can create a submarine living space bubble at a cost of 331 euro / cubic meter …. i agree on your concept – when you want living space in the open ocean, capeable to survive a 100 year storm and provide movement free living space, you need to make it curved (bubble shaped) and submerge it a few feet…

square is possible but has its drawbacks clearly visible in the following videos of the ecuadorian coast guard base (building and float out) – as discussed in: “Apply Seasteading Concrete Shell Structures” thread page 12/13 link

among those drawbacks are: loss of resistance compared to curved walls, difficulties at building (needs big infrastructure) at launch (needs big launch site) and at sea (unpleaseant movements unless 100m diameter), give away mobility.

Wil

concretesubmarine.com

#15032

shredder7753
Participant

i couldnt wait to prove i was right and ellmer was wrong. but apparently what he said was true. even a bergstead will pitch and roll a lot in the waves Update; after the mooring line was attached and there was a current the structure stabilzed enough to be acceptable. but i still have another idea; BAFFLES:

i would have to make the hull much deeper and add these 3-D plus signs. then there would always be a minimum amount of ballast water in the bottom. as the structure tries to pitch and roll the baffles will slow the motion down a lot.
octavian – the hull is just a basic shell right now. the design calls for bulletproof lexan windows that do not open. the walls are much thicker in this demonstrator than they would be at scale (12in compared to 8in deep). so as u can tell the real thing would sit much higher in this condition.
emmett – thanks for the explanation.

____________

My Work II

“Leadership and do-ership are not the same thing”

#15035

shredder7753
Participant

these waves are maybe 2 feet high

at scale, i am a 138ft tall giant

theres a bunch of new clips i just made. check her out at my channel!

some of my videos still have 0 views. try this one: http://www.youtube.com/watch?v=1yO1FUXM7uw&feature=related

note: Ellmer wants to say

among those drawbacks are: loss of resistance compared to curved walls, difficulties at building (needs big infrastructure) at launch (needs big launch site) and at sea (unpleaseant movements unless 100m diameter), give away mobility.

but he fails to make a measured comparison between the two designs. concretes greatest ability is its compressive strength. that is why it enables us to make flat walls and not curved. when i was in the pool with the new shell, the LAST thing i was worried about was the walls caving in. even when i did the meteoroid test. for crying out loud! u were not there to see it but i picked the whole thing up with just my 2 hands! that put the entire weight in a very small area. you do not need to have a round structure. you need basic steel reinforcement.

he also claims that it would be too expensive to build. my 10m x 10m design is the exact same weight as his 200-ton sub yacht (AND OFFERS A LOT MORE ROOM)! how could it possibly be any easier to build and manipulate a curvaceous sub-yacht than a bergstead. thats just crazy!

my point is, wilfred ellmer is ticked off that i built on his idea that never made him the fame and fortune he hoped for and i made a much better design with it. dude – you’ll get some free passes to vacation on one.

dont dismiss an entire idea just because one small aspect hasnt fully developed yet.

____________

My Work II

“Leadership and do-ership are not the same thing”

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