Ok; If you take a 186 lb chunk of railroad track and hoist it 75 ft. up a tree and at about 50 ft up you anchor a old chounaird #8 stopper and too that you girth hitch a 24 in 1/2 in new dry nylon runner tied with a water knot with 4 in tails, and to that you clip an old chouinard oval, and you secure the 11mm dynamic rope (retired) to the base of the tree, and you drop the railroad tie,you get...
a BIG PIECE OF STEEL EMBEDDED IN THE GROUND, AND A RUNNER THAT SNAPPED,YOU GUESSED IT, AT THE GIRTH HITCH!
its not "scientifical", its REAL world!!!