I never heard/thought of it either. Saw this recently in a FB post by Bailey's:I've never heard of chain wrapping til here either.
150' Up Still 7 Ft. in Diameter
"The chains and binders above and below the cut are used to help avoid splitting, and a possible barberchair."
http://www.baileysonline.com/Media/Posters/Logging/Jumbo-150-Ft-Up-Still-7-Ft-in-Diameter-Poster.axd
Philbert