sda97 - Interesting question. I have been "rummaging" around, and have found little, other than plans for backyard sheds and homes by "do-it-yourselfers".
Then I remembered a small pamphlet in my library. It is "The Kansas State College Bulletin No. 42". Title is "The Design of Barns to Withstand Wind Loads", by F. C. Fenton and C. K. Otis. The date is November 1, 1941. There are bibliography references to it on the web, but it appears to be out of print (not surprising). It contains quite a bit of technical information on gambrel, gable & gothic roof barn design.
It will take me a while, probably a week or two, to dissassble the pamphlet, scan the 76 pages, print (.pdf format) & post the document on my website (link below). Will let you know (here) when it is available for download.
Thanks SlideRuleEra. The information will be appreciated. The gambrel roofs are interesting structures. I'll bet most of them were designed by the seat of someone's pants.
I was told by an old carpenter once that the trick was to have all 5 "points" of the gambrel fall on the line of a half circle...
this actually may be true, but it sure leaves a lot of possibilities...
be sure to post what you find please, i'm very interested in the subject as well. I tried to model one in Ram Advanse once just for kicks, and although i could size members, the trick for me would be how to design the connections...(which is probly the most important part)
I have the .pdf file of "Design of Barns to Withstand Wind Loads" posted on my website (link below). It is in the "Miscellaneous" section near the bottom of the home page. The pamphlet discusses using split-ring connectors (and other fasteners) at the joints. So, I have also digitized & posted "Fabricating TECO Timber Connector Structures" (from 1942) on how to install split-ring connectors. They are still made, you can download the catalog and design manual at this link
My uncle, a structural engineer, used the two documents that I have posted in his work. During World War II he was employed by the US Army Corps of Engineers designing large wooden hangers (because of steel shortage) for military aircraft and blimps. He always said that split-ring connectors make the very best (wood) joints.
