"While working on something else, I stumbled over this shape. For lack of another name, it resembled a kind of girder that gently twists and thus I named it so.
It's hollow like a tube but closed at the ends. Closing the structure at the ends makes it completely rigid.
I don't have time to experiment at the moment so I'm putting it out for sharing for anyone who wants to have a go at experimenting."
3 different lengths.
Same piece from 3 different angles.