DMM drop tests on slings

[Pete Bannister]

Well presented video showing the effect of fall factors and sling properties on impact forces and failure. Sorry if the link has been posted before. Watch the movie at the bottom of the page.

 

How to Break Nylon & Dyneema® Slings [Vid] — Knowledge — DMM Climbing

 

food for thought!

[Tony Croft aka hamadryad]

good post pete

[slack ma girdle]

Food for thought, particularly for rigging applications where the ropes we use have very little stretch.

[Marc]

Food for thought, particularly for rigging applications where the ropes we use have very little stretch.

 

Also consider are climbing lines are static not dynamic so about equal in the stretch, so food for thought to all you homemade rope guide users who are using a dyneema sling as the prussik pulley adjuster!!

[Tony Croft aka hamadryad]

weve just bought a polydine lowering rope, apparently it done well against double esterlon in drop tests and can see why its got a nice loose weave to it that bunches up a bit like the gEFA bracing stuff.

 

I will be loooking into amounts of dyneema in my climbing lines from here in too, its great for wear and wieght but like this vid shows, shocks not so good

[Marc]

weve just bought a polydine lowering rope, apparently it done well against double esterlon in drop tests and can see why its got a nice loose weave to it that bunches up a bit like the gEFA bracing stuff.

 

I will be loooking into amounts of dyneema in my climbing lines from here in too, its great for wear and wieght but like this vid shows, shocks not so good

 

you will like this video then

 

[ame=http://www.youtube.com/watch?v=WDIo-WZkSaM]Yale Cordage Ultrex vs. XTC Rope Static and Dynamic Test Demonstration - YouTube[/ame]

[DrewB]

Weve changed from using dyneema webbing slings but to be fair we never did manage to break any through drop testing the rope guides.

[ame=http://www.youtube.com/watch?v=IiiodscSlS4]DB Tree Rope Saver Test - YouTube[/ame]

Thats a 100kg weight falling 4 metres and i think it was the 6th drop in that vid

[Pete Bannister]

Drew, that's really interesting. Thanks for the post.

I couldn’t really make out the details of the rigging from the video.

Looked like a fall factor 1?

Apart from the tree, what were the 'elastic' or friction generating linkages in the system, other than the webbing sling itself?

[DrewB]

The weight was tied a vt Ina dbrt system. The weight was next to the rope guide with about 2.5 m slack in the system. The anchor was a big oak limb that was way above normal anchors! Goes to show what a great shock absorber the tree itself is

[Tom D]

Very surprising the forces that can be generated only falling a couple of feet, I have done that on several occasions. Really highlights the importance of good rigging technique and equipment.