Rope and climbing stuff
This is not a site for comprehensive, 100-sample statistical tests; I rarely break or otherwise test more than 5 replicates. Most of my reports describe one-off tests, on gear I sew or splice. I am very consistent in the ways I make soft goods, which have fairly obvious failure modes. There are a few thermal tests on hard-soft systems, but few break tests of hard goods (e.g. small quicklinks) which break at forces I cannot measure (the practical limit of my fast load cell in 5000 lbs). The linescale 3, used as a loadcell in many of these tests, seems to have an inherent "slop" of about +/- 15 lbs at the low end, up to my body weight (about 150 lbs) at high sampling rates (640 Hz).  I get much better low-end (5-300 lbs)  reproducibility with cheap hanging/crane scales; but these sample at 2 Hz at best, whereas the linescale can sample up to 1280 Hz. At low sampling rates (e.g. 10 Hz), the linescale 3 has pretty good agreement with calibrated hanging scales. At high sampling rates and forces above 1000 lbs, the linescale 3 seems to be about 2% accurate


241218 Apparent forces felt by top-belayer when rope is run over rock. https://hwstock.org/rope/capstan/
241128 Hand-sewn loops in webbing: number of UHMWPE stitches needed to reach optimum strength. https://hwstock.org/rope/sewnweb/
241101 Does heat typical of cleaning weaken PET ropes? https://hwstock.org/rope/heatPET/
241025 Loss of strength in canyon ropes-- dirt vs. long-term underwater. https://hwstock.org/rope/strengthlosscanyon/
240516 Ropes running over a bare sling (no quicklink)...what actually matters? https://hwstock.org/rope/slingmelt/
240322 Hand-Sewn Loops: Break at 196% for 16mm Webbing, 167% for 5 mm Cord https://hwstock.org/rope/dogbone/
240315 Knots for Amsteel (Dyneema) for "Smooth Operator" in Canyons https://hwstock.org/rope/smooth/
240201Titanium vs. Aluminum for rappel devices-- a matter of thermal conductivity. https://hwstock.org/rope/Ti_vs_Al/
231210  Sewn Amsteel stronger than end-for-end splice https://hwstock.org/rope/sewnamsteel2/
231129 Girth-hitched Amsteel Eye Breaks at 77% on Carabiner, 100% on 2" pipe. https://hwstock.org/rope/girth_amsteel/
231027 Strength of sewn loops girth-hitched in dyneema/HMPE  https://hwstock.org/rope/sewn_loop_girth/
231005 Why so much hate for small quicklinks? https://hwstock.org/rope/3_16ths_rapide2/
230909 Abrasion tests on 1/8" Amsteel and PET cord. https://hwstock.org/rope/abrasion/
230829 Rapping and acsnding on coreshot ropes: ATC and mechanical ascender versus hitches https://hwstock.org/rope/coreshot2/
230811 More about sewing cords. https://hwstock.org/rope/sewing/
230719 Dyneema is slippery... but when and where? https://hwstock.org/rope/binerpulley/
230624 The relative resistance of slings to cuts by rocks. https://hwstock.org/rope/rockcut/
230304 Will raps on thin Amsteel Dyneema kill you? https://hwstock.org/rope/willdyneemakillyou/
230221 Critter damage to Dyneema vs. Nylon/polyester. https://hwstock.org/rope/critter/
221031 What happens when you rap over core-shot ropes with Dyneema cores? https://hwstock.org/rope/rap_core_shot/
220806 Would short sheaths make Amsteel knottable? https://hwstock.org/rope/sheathed_amsteel/
220805 Break test of sewn eye in 2500 lb bs Amsteel. https://hwstock.org/rope/sewn_amsteel/
220719 Break test of Trilene "Knot" in Amsteel (Dyneema). https://hwstock.org/rope/amsteeltrilene/
220614 Breaking a 4 mm, sewn, eye-to-eye prusik used for schwabisch knots. https://hwstock.org/rope/eye2eye/
220612 Can an EDK be used to join two webbing straps for an "easy" rap? https://hwstock.org/rope/edk15mm/
220611 Do urethane coatings weaken knots in rope? https://hwstock.org/rope/coatknot/
220608 Amsteel left in sun 3 years breaks at least at 80% original strength. https://hwstock.org/rope/oldamsteel.htm
220608 Titan tech cord (dyneema core): knotted versus sewn. https://hwstock.org/rope/titansew.htm
220507 Can you trust a cord girth-hitched to the bottom biner hole of an ascender? https://hwstock.org/rope/girth.htm
220504 4mm Dyneema and tiny quicklink against 10.2mm nylon dynamic rope: https://hwstock.org/3_16ths_quicklink_pull_test/
220315 Thoughts on butterfly knots and core-shots https://hwstock.org/rope/butterflies.htm
220101 Dyneema Rap Chronicles: https://hwstock.org/dyneema/dnew
180724 UIAA drop tests and "Sharpie" pen middle marks for nylon ropes. http://hwstock.org/rope/UIAA-middle.pdf
160510 Thoughts on fixed ropes http://hwstock.org/fixed.htm