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Author | Topic: That boat don't float | ||||||||||||||||||||||||||||||
iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
If I could er... row in here for a minute.
What would happen if the ark, instead of being made along traditional lines, was of woven construction (inspired perhaps by the smaller scale Moses-basket Structual strength: because the ark is uber flexible. Leaking: because the structure is open and relies on the buoyant nature of the wood itself and not the airspace contained within the hull for floatation. The open nature of the structure would tend towards solving your waste disposal/ventilation issues too. Passively rather than actively - indicating God's design to err towards the labour saving/eco-friendly. Edited by iano, : No reason given. Edited by iano, : No reason given.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
quote: Assuming it's made from a material less dense than water (ie: most woods) then of course it doesn't matter how big it is - it'll float quote: Why not? Empty, a woven balsa vessel would barely 'dent' the surface of the water. As you load up it'd sink lower and lower into the water. A point would come when it sinks low enough to submerge the lowest stored animals (because the water level rises inside the ark). At which point you've reach max capacity. You could improve things by weaving a more open structure above the waterline (to reduce weight) and increase density of weave below the waterline to increase buoyancy (and so increase animal storage capacity). quote: As per your typical ship. The point is to address the structural considerations of the OP quote: It would have been God-designed and Noah-built. Perhaps God likes us to discover things for ourselves. It's more fun for us that way. quote: Maybe he had lots of time instead of lots of man power. A woven structure strikes me as something you can just plug away on without any great need for large engineering works. Edited by iano, : No reason given. Edited by iano, : No reason given.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
The OP's objection has to do with a vessel this size taking to water and that's what I'm addressing. It is sufficient, I think, to note that a vessel this size, whose unladen form barely dents the surface of the water, could hold a significant number of (unspecified) animals. Indeed, were the designed-to-be-submerged volume fitted out with balsa wood then buoyancy would be further increased - increasing load carrying capacity still further
Like this you mean?
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
Just having a second look at this - and correct me if I've calculated wrongly. The ark dimensons in metres are approx L=156, B=26, D=15. We're assuming construction from a balsa wood weave - in which the submerged volume of the vessle is filled mainly with wood to increase buoyancy. If we assume that the loaded up vessel is 50% submerged then the load carrying calculation would go like this: Volume of submerged section = 156 x 26 x 7.5m = 30420m3 Assuming the above sumberged volume is 30% water and 70% wood (because the structure is woven and not solid) we have a submerged volume of wood = 30420 x 70% = 21294m3 The weight of that wood would be a function of the density of balsa wood (170kg/m3) which works out at 3619 metrc tonnes. The buoyancy generated by this amount of submerged wood is the same as it's weight minus x it's relative weight (ie: the same as it's total buoyancy minus the buoyancy required to stop itself from sinking). Thus (3619 - (.17 x 3619) = 3004 metric tonnes. The load carrying capacity of this glorified (literally) raft is 3004 metric tonnes divided up into structure above water, animals, food however Noah saw fit Seems that there'd be room for a fair few animals to me..
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
quote: I've no idea but the tonnage above allows us to at least suppose there could be many. The OP has to do with wondering about vessel mechanics - not every issue arising out of the ark account. quote: I'm not supposing anything I don't have to suppose. I'm told a large craft took to water and that it rained alot. I only need it to float and stay together sufficiently well on water to last for the duration. I've supposed half in, half out of the water in the post above. Lets agree that the lowest deck was 6ft above normal water level to provide a margin of comfort and that the hole in the roof was to allow giraffes to stand up and stretch their legs from time to time. Edited by iano, : No reason given.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
As I say, this isn't really the concern of the thread. It's about the floatability of a boat.
Maybe Noah brought an unwoven box with him?
It's like knitting, is weaving. It's relative easy and if you just keep going the garment will get bigger and bigger. And the aim is more float than sea ..worthy Edited by iano, : No reason given.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
The weaving isn't whats relevant to floatation, it's buoyancy. If the wicker sinks it isn't buoyant. Lots of woods are.
To stop the wood becoming waterlogged and sinking perhaps?
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
Perhaps it's because it takes a lot more wood to build a raft capable of carrying the same load as a hollow hulled boat? Meaning it's cheaper to build a hollow hulled boat. And you get the benefit of increase storage volume (for the same weight carrying capacituy). These are very good reasons to avoid a woven raft.
We don't know where the ark was, for how long into the rains before it floated. We don't know how sheltered from wind and rain it was. There's a whole raft (oops) of unknowns about which we could speculate all day. At least we are far enough to have a simple-enough-to-construct vessel which will float without cracking to bits so as to leak its way to the bottom. Remember ventilation and poo-disposal characteristics too. Not things to be sniffed at.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
It's woven because that is a relatively easy structure to construct with basic tools and techniques. It's woven because that offers flexibility. It's woven so that wind and water flow through the structure rather than exert load on the structure. It's not woven to take on water I see far fewer problems here than I do with a ship and await something (technically) specific to support your ongoing sense of incredulity.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
![]() Anything to avoid dealing with the leaky-planking brigade.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
quote: Ship? Whose talking about a ship? A ships job is to go places; to be steered there and to propel itself or be propelled there. It typically has to keep an eye on construction costs too. This is a liferaft designed for a unique purpose. Money is no object. Of course you're not going to see it's design commonly used. quote: What's to test? Rafts float on water (once made from lighter-than-water materials) and that's all this vessel is. The unanswerable question is whether this vessel had to manage storms and significant waves. If not then I don't see what the problem is. And it doesn't appear to me that you do either. Edited by iano, : No reason given.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
Hi RAZD. I hope all is well. When the vessel isn't based around an air containing hull then it matters alot.
Of course. And in our balsa wood model the relatively low weight of the wood involved permits higher other-load carrying capacity.
Agreed. An earlier post contains a calculation based on the ark being 50% submerged - with the submerged volume made up of woven balsa (70% wood/30% space iirc). The water displaced gave an above waterline load carrying capacity of 3000 metric tonnes or so. You have less load carrying capacity than a sealed hull construction - for sure. But you also have a vessel that is immune to the problem of leaks - swells passing right through it.. so to speak. Edited by iano, : No reason given. Edited by iano, : No reason given.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
Balsa below the waterline provides optimal buoyancy. Other wood can be used in construction to provide good wear/localised strength characteristics - think of GRP coated polystrene surfboards. Not that balsa wood should be considered weak, think: De Havilland Mosquito. However, given that some folk object to the use of balsa on locational availability* grounds we could always switch to cedar, Lebanese cedar solving the locality problem perhaps. It's not as light as balsa so we'd have to reduce our above-waterline load carrying capacity to something like 1,500 metric tonnes (or 1,490 metric tonnes if we subtract the aforementioned pair of African elephants).
Backpeddling? What backpeddling? *it could be that the YEC argument permits an alternative model for continental location at the time but seeing as I'm not aware of what that model is we'll suppose balsa wood out. Edited by iano, : No reason given. Edited by iano, : No reason given.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
It's not 'any' force. It's mucho reduced force - compared to what a traditional closed hull structure would undergo. If it's a good enough idea for fishermans nets then it's good enough for Noahs ark.
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iano Member (Idle past 1180 days) Posts: 6165 From: Co. Wicklow, Ireland. Joined: |
There's no math in the OP. Nor here. The OP approaches things from a credulity point of view and is correct (in my view) in supposing it impossible to create a watertight hull (placed on even a calm sea) by traditional shipbuilding means. He uses the example of a similar sized wooden hull to illustrate his point and works from there. Remember:
I'm suggesting more floating platform/less ship. It doesn't stretch credulity to suppose that an intrinsically buoyant structure would be capable of floating on water whilst carrying a load. There is no need for pumps, no need for caulking, no need to dispose of waste and no need to feed (assuming feed was put in place beforehand and the animals fed themselves). We've no way of knowing what the sea conditions were in the locality of the ark and we shouldn't necessarily suppose 'stormy'. To that end, we can suppose the possibility of a calm-ish sea which isn't (credulity suggests) going to tax a structure through which a swell can freely move. If it floats your boat, imagine a series of smaller rafts daisy chained together rather than a single monolithic structure. Something that could be expected to roll with the waves. Then come back with your objections.
Be careful that your objections rise above rhetoric lest you fall on your own sword in this regard. Edited by iano, : No reason given. Edited by iano, : No reason given. Edited by iano, : No reason given.
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