Comments on: Dyneema vs Nylon Sling Drop Test

By: Francois

Francois — Mon, 28 Mar 2011 19:59:51 +0000

Not sure I fully understand the science (actually I’m pretty sure I didn’t get it!!!) of the test but what I got are the general messages of “don’t build anchors with slings” and “don’t leave slack in an anchoring system”. On those points, the experience was a success.

By: Paul

Paul — Sun, 25 Jul 2010 00:21:08 +0000

These tests create a false impression. The force felt by the sling is given by F=dp/dt where dp is the change in momentum of the lead weight and dt is the time over which the momentum changed. By using a solid weight in the tests with all pieces of the system engineered to be static, the testers made dt extremely small. This causes the force to spike up to very large values for a brief moment and break the slings. But the human body in a harness would NEVER act the same as a solid weight. We are floppy and squishy blobs. If a human was in a harness in that test, the slings never would have broken. The momentum change would have been spread over a larger time interval and F would have remained small. I’m suspicious that the people who did this test are willfully misinforming climbers…

By: effdude

effdude — Tue, 13 Jul 2010 23:15:32 +0000

S.R.E.NE: SOLID, REDUNDANT, EQUALIZED, NO EXTENSION. Build your belay anchors using this acronym and this should not be a problem. Good info. though.