A report by Don Bogie, 2005.
The strength of snow anchors is dependent on a combination of the strength of the snow in compression and shear, the strength of the materials the anchor is made, the strength and placement of the attachment system, and the mode of use, angles and orientation of the anchor and its attachment system.
This report led to the development of snow anchors in the Rope Rescue & Rigging Field Guide.
Two-Point Anchor Angles: The Simple Trig Behind The Rules Most rope courses teach an anchor angle rule. The usual version
The post tackles a practical question for backcountry rescue teams: is 16mm tubular webbing strong enough for anchor rigging, given the appeal of reducing weight in a rescue kit? To find out, the team ran a series of pull tests comparing different wrap-and-pull configurations — Wrap 1 Pull 1, Wrap 2 Pull 2, Wrap 2 Pull 1, and Wrap 3 Pull 2 — across several real-world surfaces: pins, carabiners, smooth rock, sharp rock, and edge-protected sharp rock. A baseline was first established using 25mm webbing before switching to the thinner 16mm webbing to see how it held up.
The post tackles a common assumption in rope work: that a smaller-radius device — a carabiner, mallion rapide, or belay device — produces more friction on a rope than a larger one, since the rope is thought to have more internal resistance as the radius decreases. To find out if this holds up, the team ran friction tests comparing stainless steel mallion rapides at 12mm, 10mm, 8mm, and 7mm, all using the same 8mm static rope. The results are checked against the Capstan Equation, which doesn’t include radius as a factor in the first place.