What is “sharp edge resistance?
With normal use there are no documented cases of a rope breaking under normal use. The documented occurrences of rope breakages in the field are attributed to pre-exposure to sulfuric acid or by being cut by a sharp edge. UIAA just recently added an optional test to UIAA 101 for testing to sharp edge resistance (UIAA 108). Many manufacturers are claiming sharp edge resistance for their ropes. The designation of sharp edge resistance is not a guarantee of safety. These ropes can still be cut. Our in-house testing shows that slight variables in the testing procedure can cause even “edge safe resistant” ropes to break on the first fall. We have recently received a letter from APAVE, the UIAA Approved Lab that we use for testing, that their “insurance company strongly recommend us to inform our customers that this test does not reproduce the reality and that the behavior of a rope in contact with a sharp edge can be radically different from the UIAA 108 test conditions and results.