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August 5, 2018

9/16 Atlas for rig line 5/8 stable braid sling large ISC block. Rope blew apart at the porty and it wasn’t locked off. Opinions on this failure?
Wondering if the line was wrapped improperly around the POW. If you change the direction of the wraps after the half wrap it can lock off. I've seen this happen, even from an experienced groundie.
 
That's a pretty nice size white pine top. They get heavy. If I were climbing I sure wouldn't go that big on that species. Anyways, could have been a good little knick in the rope or what arian climber said. Looks like groundie had it running okay right off the bat. A 5/8" rope and 3/4" sling would have probably been a better choice. Hope it came down safe!
 
Honestly, before I even clicked on the thumbnail or read the description, I thought that piece looked way too big for that rope. (9/16 is pretty sturdy, but that was a big top.)

I'm guessing you cut it there because that was the limit of the bucket. I'm not knocking you because I've been there. I probably would have used a bigger rope, or sometimes I'll actually bring up an extending power saw and cut the top out with that. Gains you an extra 12 or 13 feet, and with a top that diameter saves a ton of weight on the rope. Obviously, climbing out to get the top is also an option, especially in a nice live tree like that. (Assuming no defects I'm not aware of).

As to why it broke where it did I'd say that was the highest stress point and there was simply too much weight. Weak points are bend points so either the knot, the bend over the block, or the wraps on the porty. Looked like a huge amount of stretch before it broke, but also looked like the groundman let it run appropriately- so guessing it wasn't locked off. Just too big.

Glad it looked like no damage.
 
Happy to get some feedback. After watching the video 6 million times and inspecting the rope after failure, I think the rope had been milking itself from all the previous leads we removed from the tree and since both ends were sealed it had no where to go thus bunching the core inside the jacket. Maybe we got to a part of the rope we hadn’t yet used and when the bunches up part hit the fair lead on the porty it blew? So many possibilities. Rope was brand new that morning kinda regret not milking it by hand with a prusik prior to using it
 
Honestly, before I even clicked on the thumbnail or read the description, I thought that piece looked way too big for that rope. (9/16 is pretty sturdy, but that was a big top.)

I'm guessing you cut it there because that was the limit of the bucket. I'm not knocking you because I've been there. I probably would have used a bigger rope, or sometimes I'll actually bring up an extending power saw and cut the top out with that. Gains you an extra 12 or 13 feet, and with a top that diameter saves a ton of weight on the rope. Obviously, climbing out to get the top is also an option, especially in a nice live tree like that. (Assuming no defects I'm not aware of).

As to why it broke where it did I'd say that was the highest stress point and there was simply too much weight. Weak points are bend points so either the knot, the bend over the block, or the wraps on the porty. Looked like a huge amount of stretch before it broke, but also looked like the groundman let it run appropriately- so guessing it wasn't locked off. Just too big.

Glad it looked like no damage.
No damage and had their been any hazards in the DZ we absolutely would not have taken that big of a top. And yes it seemed to run appropriately and 100% failed at the POW
 
No damage and had their been any hazards in the DZ we absolutely would not have taken that big of a top. And yes it seemed to run appropriately and 100% failed at the POW
Breaking strength of that rope is something like 12-13k lbs I believe. Needless to say the stable braid is in the mail!
 

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