: Assuming of course I can split an 8-9 foot log of hemlock, get it
: squared off, and convert a portion into a board, will it work
: for bending for ribs?

Depending on where you like...

I assume you're talking about the conifer in the genus tsuga (unrelated to the plant poison-hemlock by the way). I know the Eastern species well. In New England we mostly have Eastern Hemlock (tsuga canadensis). My land was covered in it. I cut cords of it for firewood when I cleared the land. For a conifer it burns very nicely. The trees I had were a royal pain to split. It's quite knotty and yielded very little straight grain. The other problem is there is a marked difference in density between early and late growth. I couldn't image trying to split a 8-9' log. You'd have 6-8 whurls of branches, each marking that years growth.

Western hemlock (Tsuga heterophylla) is a different beast. It grows much larger and yields clearer boards. You'd have better luck splitting it.

You still have to bend it...