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Whiptail stitched terminations produce good break-test results

Whiptail stitched terminations produce good break-test results

Richard Tregoweth - Sunday, October 21, 2012

Treetools will commence sales of locally produced stitched rope terminations next month. The 'Whiptail' terminations are manufactured in Auckland by custom rope stitching company Shift 2. Stitched terminations will compliment the splicing work currently undertaken for Treetools by DB Tree (not all ropes can be spliced).

Shift 2 have their own tensile strength testing system, conducted independently by Christchurch-based SAI Global, but Treetools wanted to be doubly sure the sewn Whiptail terminations really did stay put!

So, we went back to what we know best - break-testing on the bench. Simplistic, yes! But it works (in our opinion).

Treetools commissioned Shift 2 to manufacturer a number of stitched e2e's out of a few common cords including a couple of dynamic EN 892 lines (Ice Line and Flashlight), kernmantle KM III and Globe 5000 and cut-resistant Sterling TriTech.

We also varied the way the stitched eyes were oriented to see what effect that might have on the final result.

Our ideal target break was at least 70% of MBS (the universally accepted break-strength of a knot is approximately 50%).

In most cases the breaks were above the 70% threshold, except for Yale Beeline 8mm where we had Shift 2 orient the eye differently (judging by the results, this is not ideal). Globe 5000 produced similar results. While the break-test results on these two ropes was below target, the overall strength is still perfectly acceptable.

When it comes to the dynamic lines, Ice Line and Flashlight, it's probably best to re-read a previous Treetools blog post on the 'dynamic' EN 892 standard before you start jumping to conclusions.

The full results are listed in the chart below.

Sewn terminations were once restricted to products supplied direct from the rope manufacturer but the arrival of Shift 2 in Auckland has changed all that for the New Zealand market. Custom rope stitching is now an option for static and dynamic lines and any number of friction cords.

Treetools will produce Whiptail dynamic lanyards to compliment the Trango Cinch (rather than the previous knotted versions). Shorter stitched Whiptail Armor-Prus e2e's are also on the product wish list.

Whiptail Sewn Terminations by Shift2

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