When a friction cord, with an exposed core Locking Brummel splice, is used in conjunction with a 'slack tending' pulley like a Petzl Fixe or the ISC Eige r there is a high likelihood of rope 'friction' heat being generated. It's the heat resistance of the outer sheath of Armor Prus that has made it so famous as a friction cord. See previous Treetools blog titled " Temperature guide for ropes ". Spectra melts at a relatively low 147.22 deg C and Kevlar decomposes at 426.6 deg C (for reference water boils at 100☌). The core of Armor Prus is a lightweight composite made of Spectra and Kevlar.
There are couple of good reasons why the answer is NO.ġ) The low melting point of the exposed core. That's why a few prominent climbers (like James Kilpatrick ) prefer to use a knotted friction cord over a splice.ĭOES THE CORE LAST AS LONG AS IF IT STILL HAD THE OUTER (SHEATH) OVER IT? The simple answer, NO!Īccording to Donahys, the manufacturer of Armor Prus, "the core should be protected at all times" and this can be achieved with both Class I and Class II splices. This action changes the dynamics of the prussic knot, which is not to everyone's liking. We'll clarify this one complaint about the Class I splice, when used with a Hitch Climber, is the fact the resulting 'stiff' legs force the prussic knot away from the fairleads on the Hitch Climber. Greater flexibility in the cord make the legs on the Locking Brummel spliced friction cord 'flex' more like a cord with a short, stitched eye like Ocean Polyester (or knotted). IS THE CORD STILL STIFF ABOVE THE SPLICE? There is no taper above the splice, which translates to no 'stiffness' in the cord (stiffness occurs due the depth of bury on a Class I splice). THE BRUMMEL SPLICE LOOKS WAY TIDIER: The fact the Locking Brummel looks tidier is subjective some will say it is tidy and some will say it is not! The 'look' of the splice, in this instance, does not influence performance. So, it is probably worth furthering the debate. Following the Treetools blog about the " Concerns regarding friction cord splices " prominent Christchurch arborist Adam Holland posed some interesting questions - see comment above.Īnd… due to the high break-test results for the Locking Brummel splice (22-24kN) on 8mm Armor Prus, other climbers have asked similar questions regarding this type of splice on friction cords.
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