three ring release

[surveyor]

Do you think this release system could have application for tree work?
http://en.wikipedia.org/wiki/3-ring_release_system

 

[Tom Dunlap]

A number of years ago an arbo configured something like that for a quick-release lanyard. Instead of using a 'weak-link' design he thought about using a 3 ring setup.

Do you have any ideas in your clever mind?

 

[surveyor]

I had thought it might be useful for a releasable redirect.

 

[GoodYautja]

how about self-retrievable rigging?

 

[tuttle]

I use a gibb snap shackle, its a 4ton one.

Just look them up, you can buy for just $5>$15 on ebay.

 

[Tom Dunlap]

I' ve got a couple of large snap shackles that I've used for retrievable false crotches. Simpler solution than fabricating the three ring setup.

 

[surveyor]

That is a clever device. Perhaps you could attach the release cord to the anchored side of the climbing line, then when pulling the rope out of the tree, it would pull the pin and release the snap.

 

[Tom Dunlap]

The few times that I used a snap shackle I treated it like a hand grenade. The release cord was always a bright color and I usually tied it off up in the tree. I'd release it before descending.

 

[Gerald_Beranek]

[ QUOTE ]
The few times that I used a snap shackle I treated it like a hand grenade. The release cord was always a bright color and I usually tied it off up in the tree. I'd release it before descending.

[/ QUOTE ]

Indeed!

 

[Adkpk]

Or just use a hand grenade and be done with it.

 

[UrbanTree]

As a weekend skydiving instructor, I've wondered how I could bring the three ring release system to work as an arborist. I've yet to come up with a good application. You will find it simple, reliable and quite smooth to release. The release cable, the yellow line in the animation, is plastic coated cable in our world. There is very little tension on the release cable under heavy loads. If built appropriately for the forces inolved, it will serve nicely as a retrievable/releasable anything. The trick will be solving the issue of protecting the mechanism from unintentional release.

 

[Daniel]

[ QUOTE ]
That is a clever device. Perhaps you could attach the release cord to the anchored side of the climbing line, then when pulling the rope out of the tree, it would pull the pin and release the snap.

[/ QUOTE ]

Don't see much use for a quick release in life support systems... What's your hurry?

 

[surveyor]

When I was in SA, the aviation dept. wanted to have the capability to parachute a man into a remote situation. This was before the three ring release was invented ( late '60's), so they would practice with the army type parachute which had the rip cord attached inside the Helio Courier with the door removed. On one such practice jump the chute was pulled by the cord as the jumper exited the plane, but the cord did not break away. The jumper was left streaming below and behind the airplane and evidently had no way to release the chute or was to terrified to do so. Inside the plane they had no knife to cut the cord free either, so they were in a pickle. They were not able to land with the man dangling below and they could not continue to fly around forever. I did witness a practice jump from inside the Helio previously, but was not along for the ride on this particular jump, and do not remember how they detached the jumper after about 20 minutes (perhaps they unbolted the anchor), but both airplane and the jumper survived.

 

[Tom Dunlap]

Gordon,

That would be one case where I'd break my 'don't cut ropes' maxim!

 

[UrbanTree]

Jumper in tow scenarios can get ugly. The towed jumper certainly had a cut away system of some sort, probably capewells. No hook knife on a static line deployment jump plane is a major no-no.

While i use them regularly from 14k ft, I'd be very reluctant to use a 3 ring for life support at work. I do wonder about using them in a tree removal scenario to transfer loads from a rigging line to a zip line.

Talk about "let 'er rip".