Excellent info and points David...

We have raise (and lowered) a few that way...It is scary the first few times...Now just use a "scaffolding tower" to do most of such things and of course it really helps to have the supper compact (and smooth operating) modern rigging blocks that we have...Our work in the Arborist industry (where a percentage of our timbers come from) have served our needs well in developing more advanced "rigging systems" for timber framing...

Your observations about wood species is exactly what we find...The last few "Dutch Barn" (more correctly "Germanic Barn" I agree) from New Jersey where hardwood, and I think that is where the "Tulip Poplar" one is??...The rest being mainly White Pine, Hemlock, etc...

Do you have any view, or theories why the "wedge and trunnel" system?