Here is something I found tucked away on a thumb drive. Been so long I can't remember where I found it.
Sweet. I've got a paper copy of a USFS yarding manual with deflection calculations. I'd seen it online but unreadable. My copy is so bad the used book store wanted to cancel my order but I insisted they send whatever they had. When I get home I'll see if I can find it and a link. Want to say "Cable logging" had a little on rigging spar trees.
Come to think of it there's a copy of a how to use wire rope (I'm thinking it's published by Robling rope company) on a drive somewhere. Lots of information on how to slack like for feeding coal, and moving all kinds of stuff that we would use a skid steer or bulldozer for today but they hadn't been invented yet. If found my copy of "Practical wire rope" but am unable to get it to load here.
"Cable Logging Systems", U.S. Department of Agriculture -Forest Service. Just put the title into Google and there's pdf copies available. Google copy might be better than the US Forest service. "Skyline Logging Handbook on Wire Rope Tensions and Deflections" by Hilton H. Lysons and Charles N. Mann 1965 is a little harder to find.
I came across this yarder manual by Worksafe BC. Cam
and here is another Worksafe manual on yarding. Cam ( let me know if these manuals open, never tried uploading files like this)
These manuals are great. Haved spent many hours over the years reading them and printed out lots of copies for my crews. Have used the info for some cool projects. Rope multi stump tail hold anchors and used my cell phone and a hammer as a makeshift tension monitor from the formulas. Great stuff for cheap entertainment if for nothing else!