let's build a ship

[Polydamas]

I think the only way to have a useful conversation would be with links to skteches and formulas on an external site. Trying to do it on a purely verbal basis is useless.

Originally Posted by whswhs

Now, let's guess at the actual dimensions of Dola's Fortune (this is what I was puzzling over on the other thread). For this I have to extrapolate from Vehicles.

We have the area of the top deck, which is 333 square feet before deduction for the mast. If we approximate its shape as an ellipse, we can estimate the area of the rectangle that encloses it by multiplying by 4/π to get 424 square feet. If we assume a 5:1 length:beam ratio, we get 46 feet long and 9 feet wide.

If we treat Dola’s fortune as a submersible, we multiply its volume by 62.5 to get a flotation rating of 307187.5 pounds. Taking this as its loaded weight, and assuming Submarine lines, gives us draft of 9 feet. Since its draft is 44 inches with a normal load, we get freeboard of 64 inches, for total height of 9 feet from keel to top deck. Alternatively, we could use the Average multiplier of 1.2 instead of the Submarine multiplier of 2, which would give us 65 inches, resulting in a freeboard of 21 inches. Would that be better for a 49-ton sailing ship? It seems more like the dimensions I’m used to seeing.

Unfortunately, 46 feet x 9 feet x 5.3 feet is 2194 cubic feet, which is less than half of 4915 cubic feet. There’s a major error factor here somewhere. Even using 9 feet as the height only gives us 3726 cubic feet. And that’s for a rectangular solid that includes a lot of space outside the hull. Something’s not right here, but I’m not sure what.

I think beam-to-length ratio is defined under Hydrodynamic Lines vel sim.

For modelling the shape of a ship better than a rectangular prism, have you looked at reconstruction plans of various ancient ships? There are a good set for a roundship in "Kyrenia II: Building a Replica of an Ancient Greek Merchantman" (PDF coming by email)