i buy the whole 'length' argument on the hewn vs. sawn - but there are other posts in the frame that are hewn. is that post the only sawn post? or are there others? if it is the only one, it may be a clue to the history of the structure... or maybe the hewer bought stock in a local mill by the time he got around to that post.



as to questions to an engineer - be careful here. find someone first that does barn repair work - then perhaps they can recommend an engineer sympathetic to your needs. otherwise you may end up with more steel cable, flying buttresses, or a sky hook.

kidding aside - a tension scarf may be tricky to pull off in situ, so you'll have to get creative with how it gets pulled together. will t. is right - correcting / repairing a barn like this is as much about rigging as it is about woodworking.

based on what i've seen (and i'm no engineer, just dangerous enough with how it all works for people to think i might be) i agree that the geometry changed and developed outward thrust at the plate. if i have time i might model it as an FEA just for fun to see what comes out.