Vasa 1628 – engineering a ship

[fred.hocker]

@Waldemar,
This is a very interesting idea. Another researcher who looked at this issue had suggested that the bilge and futtock sweeps were not only arcs of circles, but the same arcs over most of the length with adjustment of the overlap ("haling down"), which I did not find entirely convincing. I like the idea of the outer edge of the floor defined as a logarithmic curve.

How would this accommodate the widening of the hull, most likely by shifting the futtocks outward on the bottom? The ship as built is about 4 feet wider amidships than the specification (17 aln/34 feet/10.098m).

Since I think that the transom shape up to the original wing transom is to the original specification, it might be possible to derive the original shape of the run from your curves.

Always good stuff from you.

Fred

 

[-Waldemar-]

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Thank you very much, Fred, for your comment and appreciation.

Another researcher who looked at this issue had suggested that the bilge and futtock sweeps were not only arcs of circles, but the same arcs over most of the length with adjustment of the overlap ("haling down"), which I did not find entirely convincing.

I admit that I (also) find it difficult to imagine the consistency or geometric correctness of such a proposal. But maybe I just lack imagination . Besides, I expect that such a ‘construction’ would have to be quite complicated in practical application (for all regular frames), which in itself should a priori rule it out.

How would this accommodate the widening of the hull, most likely by shifting the futtocks outward on the bottom? The ship as built is about 4 feet wider amidships than the specification (17 aln/34 feet/10.098m).

Yes, of course I will give it a try. I love solving puzzles of this type, and that is probably my main motivation to continue. Specifically, I will start by literally redrawing the contours of the futtock and bilge assembly from the museum plan, and then individually rotating them with the centre of rotation lying on the line of maximum breadth. Then we'll see if anything promising comes of it...

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