We are thinking that the body can be made using either a Round Culvert:

or a Box Culvert:

They can be made from Marine Aluminum so they can last.

We will want "Longitudinal Stiffeners". These are beams running along the length of the culvert. At least some of the companies selling culverts sell these for their culverts. We need to figure out how much of this we need. Ideally the company selling the culvert would help with this structural engineering question.

Either type of culvert can be bought in sections that bolt together. So shipping to anywhere is possible.


  1. I imagine a round culvert handling rotational forces with less trouble than box culvert. So I am more confident that with enough strength in longitudinal stiffeners that a round culvert of some length can be made to work as a Seastead. But if the engineering shows that a box culvert can work I would rather use that. A flat floor is easier to use as is.
  2. Conteches.com engineering guidlines mostly for culverts used as culverts but can be some info for us
Expect we need reinforcing ribs at the ends and where the legs attach.

Other possible body shapes

A pedestrian truss bridge shape could be interesting.

Go to seastead.ai.