Phi Golden Ratio Boat Designs

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This topic contains 17 replies, has 4 voices, and was last updated by  elspru 3 years, 6 months ago.

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• #1449

elspru
Participant

So we’ve been discussing designs of boats and seasteads,

Ellmer has noted that having a large carrying capacity is beneficial,

and I’ve mentioned that geometric balancing can help the craft be stable under various loads.

To make Phi Golden Ratio boat-design simpler,

we can use the Golden Fibonacci sequence,

1 3 4 7 11 18 29 47 76 123

To this end, here are some boat designs,

on the left is free-hand inspirations, approximating phi,

and on the right are precisely measured phi golden-ratio models.

So the first measured-model is 1:3:4 height:width:length and looks stunningly like a contemporary motorboat dinghy.

The second measured-model is 3:4:7 height:width:length and appears like the spanish galleons minus the aft-decks.

Anyhow so this displacement-model if we put it into meters, is 3:4:7 meters or 10:13:23 feet.

3m*4m*7m=84m has roughly 80 metric tons of displacement, somewhat less due to rounded bottom and edges.

If we make the hull 5 cm thick ferrocement

(3m*4m*2+3m*7m*2+4m*7m*2)*5cm * 2400kg/m^3 = 14.64 Mg

it’ll weigh about 14 tons, and material costs at \$300 a ton, so \$4,200 within my price-range.

I’m not allowed to own anything over \$5,000, at this point in time, or I’d be evicted and lose my income.

Once we sail away on the boat, in the safety of wilderness, we’ll be free to own and grow, as we please.

Anyhow, so I’m wondering what you think of the design, and if perhaps you have some suggestions,

Currently only 14/80 or 17.5 percent is the unloaded water-line, I’m wondering if that is sufficient.

What is considered the optimal for sailboats nowadays anyhow?

#12560

elspru
Participant

For a smaller boat design the size of a dinghy,

perhaps 0.5:1.5:2 meters height:width:length,

0.5 * 1.5 * 2 = 1.5

with 1cm thick ferrohull

(0.5m*2m*2 + 1.5m*2m + 0.5m*1.5m*2)*1cm * 2400kg/m^3

that’ll weigh around 157 kilos or 350lb,

can be moved by 3 strong people.

portland-cement is \$15 for 40kg,

so I’m estimating cost of materials be about \$50-\$80.

Of course I’ll also have to get a portable welder, safety equipment, camo-blanket,

so it might be \$250 once all that is accounted for.

still very valuable experience and tools for a future ferroboat owner.

calm aware desire choice love express intuit move

#12604

Anonymous

Look for the space you need/want first… If it’s ONLY you and your stuff, then it’s one size. For each additional person, it grows incrementally larger. Storage is a ‘per person’ MINUS commons (Kitchen, bathroom and such). Look to Traditional Japanese architecture for space:storage ratios. Multi-function space was a very developed system, hundreds of years ago.

What do you need more space for…? If you plan to grow anything, there has to be addittional space for that…

Hull thickness is a function of durability. What does it have to do? If it’s going to submerge, it has to withstand the maximum that you AND nature will throw at it… A sub, at 20 meters, in 50 meter waves, has to withstand 70 meters of depth…

What power storage? Solar is great, but you need storage… Batteries take up space and displacement… Current normal storage for stand-alone solar, is something like 5 days TOTAL possible energy use, times 5… Batteries don’t like discharging below 80% capacity…

Given these cariables, what do you think you need? 1 person needs a month of supplies and time/space to provide the next. 2 people need more. A family gets complex fast (I am married and between us, we have 5 kids, all at home…).

Of note is that I say this, not to discourage you, but to help develope a proper plan and a space that can handle the load you will eventually demand of it. I do NOT say anything negative, I just say what I believe to be frugal. To quote something I learned long ago: “Proper planning prevents piss poor performance.”

Dude, much as it sounds like I rag on you, I just want you to think on what could happen to you and those with you, in the voyage into the great unknown. We may never meet in person, BUT, I hope we do and find we genuinely like each other.

Later,

J.L.F.

Never be afraid to try something new…

Remember, amateurs built the ark, professionals built the Titanic.

#12605

Anonymous

A ferrocement dingy that small shouldn’t need 3 people to move, except, maybe, on land. It’s a normal ‘rowing’ size and, while total displacement is calculable, a light load makes it rowable by 1… If it’s a fishing boat, the first one ever known to be made is still water-worthy, over a hundred years later. You don’t expect it to be loaded to the top, with more cement, do you?

Later,

J.L.F.

Never be afraid to try something new…

Remember, amateurs built the ark, professionals built the Titanic.

#12621

elspru
Participant

J.L. wrote:

A ferrocement dingy that small shouldn’t need 3 people to move, except, maybe, on land.

yes, that’s what I meant by it needs 3 people to move.

planning on building it next to a pond,

so have to have a way of getting it into the pond.

also it would be nice if we could take it with us,

though I guess we could also just leave or sell it.

in any case would have to go up a steep-hill,

to get it to the river, or a trailer.

It’s a normal ‘rowing’ size and, while total displacement is calculable, a light load makes it rowable by 1…

If it’s a fishing boat, the first one ever known to be made is still water-worthy, over a hundred years later.

that’s really great to hear gotta love ferrocement boats.

You don’t expect it to be loaded to the top, with more cement, do you?

nah, not for the dinghy.

would have a tought time fitting in a 0.5 meter high boat anyhow.

calm aware desire choice love express intuit move

#12624

elspru
Participant

J.L. wrote:

Look for the space you need/want first… If it’s ONLY you and your stuff, then it’s one size. For each additional person, it grows incrementally larger. Storage is a ‘per person’ MINUS commons (Kitchen, bathroom and such). Look to Traditional Japanese architecture for space:storage ratios. Multi-function space was a very developed system, hundreds of years ago.

What do you need more space for…? If you plan to grow anything, there has to be addittional space for that…

Hull thickness is a function of durability. What does it have to do? If it’s going to submerge, it has to withstand the maximum that you AND nature will throw at it… A sub, at 20 meters, in 50 meter waves, has to withstand 70 meters of depth…

woah 20 meter waves that’s like a ten story building.

even in the south-pacific/antarctic waves on average are only 8 meters high.

What power storage? Solar is great, but you need storage… Batteries take up space and displacement… Current normal storage for stand-alone solar, is something like 5 days TOTAL possible energy use, times 5… Batteries don’t like discharging below 80% capacity…

well i’m thinking of batteries as only a temporary or short-term solution,

in long-term want to have oxyhydrogen energy storage of electricity.

Given these cariables, what do you think you need? 1 person needs a month of supplies and time/space to provide the next. 2 people need more. A family gets complex fast (I am married and between us, we have 5 kids, all at home…).

Ya, okay, I can see the benefit of having more room certainly.

80 cubic meters should suffice for 4 people.

Of note is that I say this, not to discourage you, but to help develope a proper plan and a space that can handle the load you will eventually demand of it. I do NOT say anything negative, I just say what I believe to be frugal. To quote something I learned long ago: “Proper planning prevents piss poor performance.”

I do lots of planning that’s for certain.

I keep a daily journal of my various plans and ideas.

Dude, much as it sounds like I rag on you, I just want you to think on what could happen to you and those with you, in the voyage into the great unknown. We may never meet in person, BUT, I hope we do and find we genuinely like each other.

Ya, well if building the small ferroboat goes very well this year,

then maybe will feel up to making the big boat next-year.

Mainly I just got to get down the frame-making part,

friends can likely help out on the plastering days.

Also I’m not sure where I’d be keeping the under-construction big-boat,

the docks in Toronto are the highest-value real-estate.

Though maybe I could get a sailing club,

or some nearby place to lend me a spot.

Then on the big-day can get a crane to set it in the water.

Though even then, we’d need money to outfit the boat with sails, rudder and all that.

I’m rather new to concrete construction and haven’t yet made a floating ferroboat.

Also I know how some boats take several years to make,

I’d prefer to be on the water as soon as possible.

Considering I have so very little yachting or boating experience,

I figured perhaps owning a used boat first could be viable.

Having a boat or owned-home by 24 or 0x18 is my goal.

8 is the number of locality or the home.

So whichever way it manifests, (used or made)

I’d like it to be accomplished.

calm aware desire choice love express intuit move

#12721

elspru
Participant

R wrote:

Greetings,

I was wondering if you would talk with me some about your golden phi designs?

sure

The numbers that you have, are they meant for just the hull of the vessel, or the entire size?

the hull

I’ve been playing around with the 3x4x7 and 4x7x11 numbers. They seem like good numbers for easthetic purposes (dimemsions pleasing to the eye), but they seem a bit steep if for the hull itself, as you were calculating. I’ve seen some yachts that are far larger than 4x7m (9×21) that only have a 1m draft, though the particular one I like to use for a base has a 4m hull, it only has a 1m draft. Does a vessel of only 4×7 need a 3m deep hull? Are there other reasons for making it that tall (Such as tall enough to stand up in without hitting your head)?

yes, that’s the main reason, the ability to walk around in the boat,

it’s still wider than it is tall however.

I’m not sure the draft actually,

though when empty it’s 16%.

or about 50 cm draft, likely deeper,

if the hull has a v-shaped bottom.

I was looking at a 2x4x7 hull with a total weight of 9 tonnes just for the hull itself and a displacement of about 45 tonnes (I used the same formula you did, but took 20% out of displacement as the hull won’t be a perfect rectangle). You could then stick a 3x4x7 housing unit on top, the top of which could be a useable deck area.

with the addition of the housing it would be 5m tall, which is more than the width, so it’ll topple without ballast.

The smallest I think i personally would want would be the 4x7x11, but I don’t see any reason to go over 3m deep.

extra storage space, could have a crawl space for instance.

also could use it for the water-ballast if you’re using it as a submarine.

So 3x7x11 weighs 32 tonnes and displaces 185 tonnes, I then have usable inside the hull, a first deck of 7×11 and a second deck of 7×11(would probably be more like 5.5×8) for a total of 231m2 of usable space (-20% of the hull as it’s not a rectangle, and 30% of the hull would probably be used for engine/fuel/potable/grey/etc. leaving a little under 200m2). Granted this hull would be \$10k vs \$2.5k for the 2x4x7, but I think it would be well worth it.

as to me they seem to be a destabilizing factor.

might as well simply make a second boat if you need the extra space.

only kind of “deck” I was thinking we might use, is for storing life-boats, air-lock and such.

having a tower or anything would hinder it’s performance while swiming under the waves.

note that the vast majority of animals and fish have their head and eyes at the high front of their body.

Personally my concerns have been the sail itself,

am hoping that it would cause little enough drag to keep the boat upright.

With such a wide-beam it’s much easier to use a crab-sail,

which has been wind-tunnel tested as the most effective sail.

one more thing is it’ll be good to have a basement of sorts,

for storying various heavy objects like rocks as a just-in-case ballast.

Do you have any thoughts on that?

I was also wondering what formula you used to figure out the waterline?

weight-of-hull/displacement = percent displacement

percent-displacement*height = draft

such as 14tons/84tons*3meters = 0.5meters

Would it be the same formula for figuring out how much the waterline would change with added weight?

yes

I’d like to see how much weight I could add and keep at least 1.5m above water.

((x / 84) * 3) = 1.5 = x = 42

42 – 14 = 28

so you could load it with 28 tons of stuff and still have 1.5m above water.

calm aware desire choice love express intuit move

#12726

Anonymous

elspru wrote:

R wrote:

I’ve been playing around with the 3x4x7 and 4x7x11 numbers. They seem like good numbers for easthetic purposes (dimemsions pleasing to the eye), but they seem a bit steep if for the hull itself, as you were calculating. I’ve seen some yachts that are far larger than 4x7m (9×21) that only have a 1m draft, though the particular one I like to use for a base has a 4m hull, it only has a 1m draft. Does a vessel of only 4×7 need a 3m deep hull? Are there other reasons for making it that tall (Such as tall enough to stand up in without hitting your head)?

yes, that’s the main reason, the ability to walk around in the boat, it’s still wider than it is tall however. I’m not sure the draft actually, since it’s dependant on load, though when empty it’s 16%. or about 50 cm draft, likely deeper, if the hull has a v-shaped bottom.

I was looking at a 2x4x7 hull with a total weight of 9 tonnes just for the hull itself and a displacement of about 45 tonnes (I used the same formula you did, but took 20% out of displacement as the hull won’t be a perfect rectangle). You could then stick a 3x4x7 housing unit on top, the top of which could be a useable deck area.

with the addition of the housing it would be 5m tall, which is more than the width, so it’ll topple without ballast.

[/quote]

Sorry, I didn’t realise you were making this a submersible. looking at the housing unit, 2.4m would be sufficient height, and as long as it is significantly lighter than the hull, it’s height shouldn’t be an issue should it?

So 3x7x11 weighs 32 tonnes and displaces 185 tonnes, I then have usable (space) inside the hull, a first deck of 7×11 and a second deck of 7×11(would probably be more like 5.5×8) for a total of 231m2 of usable space (-20% of the hull as it’s not a rectangle, and 30% of the hull would probably be used for engine/fuel/potable/grey/etc. leaving a little under 200m2). Granted this hull would be \$10k vs \$2.5k for the 2x4x7, but I think it would be well worth it.

I’m very confused about your decks and all, as to me they seem to be a destabilizing factor. might as well simply make a second boat if you need the extra space. only kind of “deck” I was thinking we might use, is for storing life-boats, air-lock and such. having a tower or anything would hinder it’s performance while swiming under the waves. note that the vast majority of animals and fish have their head and eyes at the high front of their body.

Personally my concerns have been the sail itself, am hoping that it would cause little enough drag to keep the boat upright. With such a wide-beam it’s much easier to use a crab-sail, which has been wind-tunnel tested as the most effective sail. one more thing is it’ll be good to have a basement of sorts, for storying various heavy objects like rocks as a just-in-case ballast.

[/quote]

The decks are just my way of saying usable floor space. I’m working on a rough design, 3x7x11 hull with a 2.5×5.5x8m “unit” on top of the hull. So I could have 1 deck inside the hull, 1 deck level with the top of the hull, and could have usable deck space on the roof (much as the bridge of most multi-story yachts). Basically a 50′ yacht.

Dimensions:

I lengthened the bow a bit, but the mean length is 11m, so I have a 5.5x7x13m max dimensioned with 2 interior levels, and a fair amount of exterior deck space. This particular design does have a 6.5x10m flat bottom lifting in the bow another 3m which would have more than 200 tonne displacement.

I was also wondering what formula you used to figure out the waterline?

weight-of-hull/displacement = percent displacement

percent-displacement*height = draft

such as 14tons/84tons*3meters = 0.5meters

calm aware desire choice love express intuit move

[/quote]

So, assuming that the vessel as a whole weighs twice that of the hull (Rounded up to 70 tonnes) it would have a draft of between 1 and 1.5m.

I’m thinking of making it a primarily surface dwelling vessel. However, it would be nice if it could be submerged for short periods of time should it become necessary. So I’m looking at figures for making the exterior surface of the upper structure out of ferrocement as well, I figure that structure would then weigh an additional 13 tonnes. That would be a total of under 50 tonnes for the entire exterior structure, allowing 50 tonnes of interior structure and accessories before going over 1.5m draft, 36 tonnes for 1.2m.

#12759

elspru
Participant

Hey I found the average new family home is about 1500 square feet, that’s 139m^2

http://www.census.gov/const/C25Ann/sftotalmedavgsqft.pdf

So made a design 4*7*11m displacing 308 tons

at 7*11 for 77m^2 or 828ft^2 per floor,

7*11*2 for 154m^2 or 1657ft^2 interior,

7*11*3 for 231m^2 or 2486ft^2 with roof.

(11 * 7 * 3) + (11 * 4 * 2) + (4 * 7 * 2) = 375

(375 * (meter^2) * (5 * centimeter) * (2400 * kilogram)) / (meter^2) = 45 Mg*m

weighing 45 tons

paid \$15 for 40kg of cement

(40 / 15) = (1000 / x) = x = 375

45(tons) * 375(dollars) = 16875 so thats about \$17,000 materials cost,

and market price is usually five times that of production,

so selling this seastead house as low as \$85,000 or 85 kilos of silver.

,

here are some pictures I drew of some more phi designs,

here the bowsprit is like a unicorn horn

and the double-keel allows it to function as a sled,

so can be operate on the ice-shelf in polar areas.

the picture of the left hand side, is of a phi shaped face or skull boat,

the angle in I figure could be used for having a more firm grip when teathered together at sea.

also I was under the impression that some speeding boats use this method, as it could lower wetted surface area.

Here I’m taking more inspiration from nature

first I looked at various tropical fish:

but then decided to use a tadpole as the basis of the boat design.

I adapted the tail as the sail, which is slightly longer than the tadpoles body.

Here is a working implementaiton of the type of crab sail I was envisioning:

here is an overview of how the boat would look like from the top,

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#12761

shredder7753
Participant

its a cool design, as long as i get invited there for pizza night

#12914

elspru
Participant

shredder7753 wrote:

its a cool design, as long as i get invited there for pizza night

wow, we’ve been making vegan pizza every night for a whole week now.

Okay, so btw, turns out that the volume of the boat is rectangle-prisim volume divided by 3.

I redid calculations for 7m boat.

760cm*470cm*290cm

= 103.588 m^3

/ 3 = approx. 34.529333 m^3

2cm thick hull. is 2cm enough do you think?

(760*470*2+290*470*2+290*760*2)*2/3*2 = 1,903,733.3cm^2

so weighs about 4 tons. half of that is cement, at 40kg per 15\$, 4000/2/40*15 cost of \$750…

The main thing would be to get a place on the lakeshore to do it.

It coudl be \$375 if 1cm thick would suffice.

my current boats seem to be a milimeter and a half thick on average,

and I can pick them at most locations, seem quite trailerable.

so assuming it costs \$750 to make, we could sell it for \$3,750.

though with mast and rudder might pust up costs to \$1,000, selling at \$5,000.

calm aware desire choice love express intuit move

#12938

Anonymous

I don’t know if I would be comfortable with only 2cm of ferro. From what I’ve read in other threads 4cm is the thinnest most people have said they would go, and I think i agree with them. The design I’m working on is 4cm outer hull with a 2cm inner hull with .25m between them broken up into chambers. Granted that’s for a bigger 12m boat, but i still think 4cm would be the minimum I would want between me and a sandbar or dock.

#12949

elspru
Participant

R wrote:

I don’t know if I would be comfortable with only 2cm of ferro. From what I’ve read in other threads 4cm is the thinnest most people have said they would go,

Ellmer was saying how 4cm is the minimum to insulate iron rebar from water.

However this is a shell that’s made of solid concrete, much like a seashell.

and I think i agree with them. The design I’m working on is 4cm outer hull with a 2cm inner hull with .25m between them broken up into chambers. Granted that’s for a bigger 12m boat, but i still think 4cm would be the minimum I would want between me and a sandbar or dock.

an 11*7*4m boat would have room enough for 4 adults,

11*7*4/3 volume 102m^3,

4cm surface area being

(11m*7m*2+7m*4m*2+11m*4m*2)*2/3*4cm = 7.9m surface-volume,

(11m*7m*2+7m*4m*2+11m*4m*2)*2/3*4cm*2400kg/m^3 19 tons weight.

cost for cement 19072/2/40*15 = \$7152

Internal volume at 102.666-7.946 =94m^3,

so that enough for 94/20 = 4.7 people, 4 adults and 2 children.

I think I’ve perhaps discovered a formula for ascertaining the width,

though I’m not certain that the metric system is the appropriate measure, As I prefer hexadecimal..

1*3*4, with 1cm, hull thickness, 4m^3 volume, weighing 416kg topless, 10.4% draft, \$78 for cement, or 608kg with cover, 15% draft, \$114 for cement

3*4*7, with 3cm, hull thickness, 28m^3 volume, weighing 5.85 metric tons with cover, 20.7% draft, \$1098 for cement

4*7*11, with 4cm, hull thickness, 102m^3 volume, weighing 19.076 metric tons wth cover, 19.2% draft, \$3577 for cement

currently my physically created models, weigh almost 50% of the allotted volume, having 50% draft,

for instance my 10*30*40 model with theoretical volume of 4lt, weighs 2kg model and can float 1.7kg.

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#13039

Anonymous

I think you’ll find that, without reinforcement, you’ll need a lot mor that 4 cm, to make-up for structural integrity. There is plenty of info on Ferro cement boat building on the internet… Eventually, it’ll be one of those ‘better-safe-than-sorry’ issues. At the scale you are currently building, it hasn’t become an issue.

Later,

J.L.F.

Never be afraid to try something new…

Remember, amateurs built the ark, professionals built the Titanic.

#13044

elspru
Participant

J.L. wrote:

I think you’ll find that, without reinforcement, you’ll need a lot mor that 4 cm, to make-up for structural integrity. There is plenty of info on Ferro cement boat building on the internet… Eventually, it’ll be one of those ‘better-safe-than-sorry’ issues. At the scale you are currently building, it hasn’t become an issue.

Later,

J.L.F.

Never be afraid to try something new…

Remember, amateurs built the ark, professionals built the Titanic.

found this at ferroboats.com

There are three basic methods of construction.
a/ Hand lay-up of netting/mesh on a rod matrix.
b/ Hand lay-up over a mould.
c/ Shot blast method.

a/ Hand lay-up of netting/mesh on a steel rod matrix, is the only method worth considering for amateur ferro-cement boat construction. Time has proved the method to be the best in almost every aspect. It’s only drawback is that it is a more time consuming construction process than methods b/ and c/. However having said that, the latter two methods are only a by-product of attempts to find quicker ways of construction for commercial cost-saving production purposes.

The disasterous effects of grounding on reefs and rocks, of ferro-cement keeled vessels (infact a monocoque constructed hull of almost any material), which have not been constructed with integral floors, has been well in evidence over the last 50 years or so. If you add to the previous analysis the considerably increased difficulties of fitting out a hull without frames. There is logically no practical reason to consider building a frameless or floorless hull. To this end I will only outline the basic two variations of this method of construction ie…’The Hartley Truss Frame method’, and ‘The Pipe Frame method’.

Ya, so frame and floors are necessary, was thinking under-floors can be ballast-tanks. could be somewhat double-hulled.

I was planning on using structural steel, just haven’t found any netting or mesh for the small scale models I’m currently building.

I’m somewhat confused about how to go about it actually, is rebar and mesh something I could get at home-depot, or do I have to go to a factory?

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