As part of an ongoing research and development program, Treetools conducts break-tests on various pieces of climbing equipment to see how they perform under simulated pressure.
Last week, in conjunction with DB Tree and Climb Every Thing, we tested a configured rope saver system on the Chain and Rigging test bed in Onehunga, Auckland. The rope saver consisted of a length of 8mm Sirius folded back on itself to make a loop, with an ART Link pulley attached via an Aspiring webbing sling choked through the loop.
The DbRT section consisted of a length of Yale Blaze with a DB Tree spliced Ocean Polyester eye2eye friction hitch. Have a look at the video below to see how the configuration behaves under load.
Unfortunately, the configuration broke 'off-screen' when the Aspiring sling pinched the 8mm Sirius enough for it to break at 20kN.
During the video you will see the ART Link 1 pulley distorting under the load particularly where the Aspiring sling attaches to the top bolt. The picture below the YouTube video shows the distortion to the top bolt hole on the pulley which clearly shows the pressure involved!
Thanks to Auckland climber, Guy Clarke for donating the ART Link 1 pulley used in these break tests. 'Gear Test' YouTube video shot by Drew Bristow.