Best way to model a flat hull bottom?

[Andrew Ford]

I’m new to DelftShip Free and absolutely loving it! I think it is amazing!

I’m modelling a hull for a Colossus class aircraft carrier. This is what I have so far:

I haven’t started work on the stern properly yet (which’ll be a rounded transom, almost a counter stern), so ignore that. I’m reasonably happy with the bow, although it needs to be “fuller” and also be slightly rounded rather than razor sharp (advice welcome!).

What is frustrating me is the flat-bottomed hull amidships. The model is based on the default yacht, with a round-bottomed hull, but I need to find a way to perfectly flatten the bottom of the hull for my model (and make the sides of the hull amidships perfectly vertical too). Here is the hull as I have it, over the Body Plan showing how it should be:

Every time this beginner nievely moves points around, or uses control curves, the hull bulges outwards and downwards and I don’t end up with a flat bottom or sides. Essentially the midships stations should be rectangular with two rounded corners. It should look a lot like a standard tanker or container ship hull. How can I reproduce this?

BTW, is it possible to start with a different “default” hull other than the yacht, such as a container ship hull?

Many thanks in advance.

Andy

[Robert Holme]

Hi Andy,

I’m pretty new at this too!

I think you need to move your station points of the midships section. Also, if station points have different z co-ordinates but the same y co-ordinates they will make a vertical straight line. Similarly if station points have the same z co-ordinates but different y co-ordinates they will make a horizontal straight line. The proximity of the lowest z point and the most outboard y point will determine the corner radius of the station.

I hope this makes sense and you find it useful.

Best Regards
Bob

[Peter Edmonds]

Enlarging on Maryak’s posting.

You may need 2 points close together at the end of a straight section to avoid the curve spreading back into what you want to be straight.You may want to try a knuckle (chine line) actually flat, by manipulating the curve, to keep the curve from propagating where it isn’t wanted.

Peter Edmonds
Naval Architect
Perth, Western Australia

[Jason Simpson]

Hi Andy,

Just wondering if you ended up completing the hull for this project ? I’m in the process of constructing a hull for a Majestic class, pretty much the same hull form. If you have completed it, could you possibly share it with me (the .fbm file that is). Email address is jason.simpson@simpsonslipways.com

Cheers Mate,

Jason Simpson

[Author]

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