Here is a drawing I have made of this roof system, and how I think it works.
and a link to a full size view:
[url= http://i538.photobucket.com/albums/ff345/HiddenOrder/Timber%20Framing/scan0001.jpg]
http://i538.photobucket.com/albums/ff345/HiddenOrder/Timber%20Framing/scan0001.jpg[/url]
The structure is a series of frameworks that support purlins, which then support common rafters.
Some things I don't quite know what to call them. For example, the structure that supports the purlins. Would this qualify as a truss? Or would you just have to classify it as a framework?
Are the timbers that directly support the purlins posts? Or should they be called truss rafters, or upper cords, or what?
They are similar to canted purlin posts, except they are canted in the opposite direction, like the roof.
A few things should be noted.
1: this assembly lacks what could be called a true tie beam. The timbers that tie, called
deckenbalken, occupy a middle ground somewhere between tie beams and joists. They are smaller than tie beams would need to be and larger than joists, and spaced closer than ties but further than joists. They simultaneously fulfill both functions.
However, it seems that the purlin supporting frame is joined into these timbers and not into the top plate (the rafter pairs however are joined to a cantilevered purlin plate.
2: The pulins can also be canted to run perpendicular to the rafters (I don't know if that's the right way to say it)
Example:
Joinery exists in many different forms. Struts for example can be either lap dovetail or mortise and tenon.