I just don't understand how we can discuss joinery without knowing basic loads, timber sizes, bent configuration, species (he did give us that), details on failure, understanding the foundation conditions, etc. etc. etc.
I think talking about old barns and their joinery is often more of an intuitive exercise than a rigid disipline. After in depth observations and studys of these old structures, which often prove highly diverse in typology and design, one begins to form a conceptual framework {pun :-)} about old joinery and the mechanics of buildings. Any framer, carpenter, scholar, restorer, hobbyist, etc. worth his/her salt can draw not only from this personal experience, but the written works of others, which often reside in the memory of one's own mind.
So when someone says an old "four-bent frame w/ dropped ties..." many of us can instinctively draw on our mental pictures and can begin to offer up suggestions. Of course we then ask for more specifics and information.
Applying rigid parameters to timber frame construction, such as the difference in the carrying capacity of ash vs. pine floor joists, is likely quite young thinking.
Designers like yourself have grown up in an environment where there is no room for error because of banks, insurance and modern building codes. All details must be proven and tested before you can even pick up a tool. You rely little on your intuition and the accumulated knowlege of the craft. I would argue that this is not a good development in the building profession.
Old joiners and carpenters knew what worked because of hundreds and thousands of years of trade progression. Their fathers taught them. They did not know about exact snowload data, nor did they need to. Barns were built from 8x8s because that's just what you did. Timber spacing was "common knowlege." These buildings have lasted and lasted. Indeed, the TF revival seeks to emulate them.
Remember that in this post we are not discussing plans for a modern elementary school. Of course we must then have all data, both known and unknown.
So when you ask about needing to understand how we can discuss old barn joinery without knowing basic loads, timber sizes, bent configuration, species, etc... relax, many of us already know the model quite well. We can discuss with no trouble.
