torque bar

Never had one break. Course my dc stocks them and they are free so we swap them about once a year...

 

I’ll pick it up with out even thinking. Lol

 

Been there done that , more times then i care to remeber. Ill probably do it again sometime soon

 

Good question.

Internal abrasion only occurs in a dynamic load event, like a rock climber falling onto a dynamic (stretchy) rope. This COULD apply to load straps IF you have a hard braking event or a collision.

Climbers ropes are rated for the number of "Factor 2" falls they can hold. A Factor 2 means the climber free falls twice the length of rope that will catch him or her. A good, modern climbing rope is rated for at least 10 Factor 2 falls. The melting of nylon (Perlon) fibers in those falls is what breaks down the rope strength.

A Factor 2 is a RARE event. I put hundreds of falls on a given climbing rope, but the vast majority of those falls were about a Factor 0.1. Very little melting occurs at such slight dynamic loads.

Static ropes are designed NOT to stretch, like a caver's rope. They are for rappelling or ascending with mechanical devices only. They aren't designed to absorb impact of a fall.

Webbing and securement straps are also designed to be static. That's so they don't stretch and you can winch them tight. Static loads don't build heat, therefore there is no reduction of strength because of thread melt.

Static breaking strength is measured on a machine I fondly called Samson. You need ear and eye protection around that machine when testing is being done.

 

You learn more here by accident, then by design.


Neat stuff