No-Knot Rigging System

[Pelorus]

From DMM's website:



If severely shock loaded, more likely the rope would break at the half hitch rather than causing a biner failure.

 

[SouthSoundTree-]

Any concern about the biner getting too much load, make it two half-hitches rather than one.

The biner can go right from clipping slings for knotless rigging to direct connect.

 

[murphy4trees]

I was going to get into more experimenting with the crosby today , but instead brought out the dyno, hooked to to the skid loader as a ground anchor. the rigging system was one block set up about 20-25' in this dead dead oak, as a redirect, and one block in a high central lead. We lowered pieces from 400-600ish pounds, with one or two cuts in the 7-800 lb range and one chunk weighing in at 1100 lbs. Mostly wanted to use this as a demonstration of the positive effects of stretch in the line acting to reduce shock loads. All pieces were lowered with 1/2" true blue, and most were locked off with 3-4 wraps and groundman told to hold so there was no run, even when negative rigging. Skid loader was parked 36" away from the tree for most of the day then moved to 75' as we got into the bigger wood and negative rigging. Stretch was very effective at keeping the peak load in the 2-3x standing weight range.. pretty cool day...

 

[murphy4trees]

here's the biggest piece we did all day..

1100 lbs.. 3 wraps, no run at all.. it was all stretch in the line and this is where it ended up.... shock load maxed out at 2300 lbs , just over 2x weight.. that says a lot about true blue eh?

No doubt there's a bunch of folks here that think it says a lot about me too.. but hey I AM just having fun.


ps.. for those that might think we were side loading this tree, the redirect block was set about 20-25' up .. I like to keep them high enough to get the line out of the groundies' way

 

[SouthSoundTree-]

interesting numbers!

 

[DMc]

I love seeing the numbers of weight and the resulting max force but you used a knot! Would a steel carabiner or Crosby hook have worked on that piece? All of us that have been using knots for most of our rigging already know what they can do. It is the topic of this thread, no-knot-rigging-systems, with which we are less familiar.

 

[Sgriff]

^ 👍👍👍

 

[murphy4trees]

tying the block to but hitch this piece: weighed in at 550 and peaked the meter at 1550... again no run in the line

ps.. ya I got a little side tracked.. would never use the crosby on a dynamic load on something that heavy.. It might work, but why bother...

 

[Levi]

The sweater returns!! Lookin sharp Murphy!