Cain Method, 7/64" Amsteel Shackle to D-Ring

[mn_booner]

I recently put an AustriAlpine Cobra Buckle with the D-Ring, on my Kestrel Flex. I climbed using the Cain method last year and had problems with the carabiner wanting to twist on the D-ring and slide along the WE step crossbar. I tried taking two segments of 7/64" amsteel and doubling them up to be used as a "shackle" so that I can attach a carabiner to the D-ring. This will let the carabiner be orientated perpendicular to the crossbar, and helps prevent it from sliding.

I have read that the breaking strength of 7/64" Amsteel is 1600 lbs, but has a recommended working load of 320 lbs (factor of safety of 5). I also read that Samson recommends a factor of safety of 10 in applications that involve "life or limb", so 160 lbs.

So in order to get this "life or limb" load up to what I feel is safe, I took two 8" continuous loops of 7/64" Amsteel, and then doubled them up. I use two different colors so I can tell if one isn't doubled up properly. If my math is right, orientating one amsteel loop in this doubled over fashion should give me 4x the strength, so by using two loops, I think I am at 160 lbs * (4 , strength due to loading configuration) * (2, due to two Amsteel loops) = 1280 lbs.

Obviously I am doing this all at my own risk, but I have been testing it with my 260 lb body and it is working good so far. The D-ring is also great for rappelling! Definetely recommend adding this to any saddle.

 

[mtsrunner]

1/8” Amsteel is 44% stronger than 7/64”. About the same price and not much bulkier at all. You have to decide your comfort level.
For that type of stuff, I prefer to make my own improved soft shackles. You get 230% of the original strength. I’m not sure about orienting the carabiner the way you want it, though.

The problem I had with Cain method is that if my spacing wasn’t perfect, my carabiner would lift up and temporarily uncam the step.