Every timber gets its name from where it is in the frame. This beam is between two posts. It holds them apart from the rafters pushing them in.
It is called a “Straining Beam”.
Here is an exploded view of one.
Sometimes, they have braces; sometimes, they don’t. Usually, it has a standard tenon at the end of the post.
Wouldn’t the rafters being trying to force the walls apart, and therefore putting the straining beam in tension, rather than compression?
In some cases you are correct Vince, however, in this gambrel barn frame example, the dynamics are a little different because the lower rafters are pushing against the plate and queen posts.
I thought the same thing Vince; it makes perfect sense. I asked my engineer and he told me the wind loads absorbed by the sidewalls and roof create an incredible amount of inward thrust. That’s why steel rods with a turnbuckle connection are used to temporarily brace an old or damaged barn until proper repairs can be made.
Jeff, I was only looking at the static load, and the snow load, trying to flatten out the roof, forcing the side walls outward. Never thought about the wind load. Thanks!