Originally Posted by Atraxia
Thanks for your replies!
The mast we have now is the original wooden mast.
I know that modern Alu masts for the same size (length) boat are not sufficient as they are too weak.
The boat weighs 28 tons.
As for the rest of the parameters, I'll get back.
You keep mentioning length when that is probably not the most important dimension. You will need to get a 68' length of mast with suitable cross section dimensions and wall thickness to get the needed strength. Perhaps someone here can help figure out exactly what those should be with the numbers they've asked for.
I shopped a lot for masts for some smaller boats, one 36' ketch
and one much smaller. It was my experience that all of the dimensions were reasonably relative to the others. If I found a mast suitable in length, then the cross section dimensions and wall thickness were adequate for that length of mast. You're right that this cross sections for aluminum
masts will be larger than a wood one of comparable length, but I've found that generally the math has already been done for you. If you find a 68' stick, it will probably work.
Good luck finding one, I didn't see anything that long on the used market while I was shopping