We broke 2 new arborist bridges and 3 old ones from Nick Markley & Hunter Vincent. They all broke super good enough above 23kN which is much stronger than your back. We weren't sure how to pull them but we decided on doing them in a U shape with a barrel knot jammed into quicklinks. If you pulled to crazy forces on your harness, it would squeeze you silly until it was pulling in the U shape or basket position we did in this test.
1st test (new bridge) broke at the knot where it jammed the quicklink at 25.59kN
2nd test (new bridge) broke at the knot where it jammed the quicklink at 25.85kN
3rd test (old bridge) broke at the knot where it jammed the quicklink at 22.89kN
4th test (old bridge) broke at the knot where it jammed the quicklink at 23.27kN
5th test (old bridge) broke at the carabiner at the load cell!!! at 26.23kN
Behind the Scenes
Nick wanted to collaborate on a video and when I started to learn about arborist gear, I realized the belay loop was very different from a climbing harness. If that is what someone is connected to then there has to be some gear fear around that and especially because it is not even traditionally tied or sewn to the harness. I bought at retail a few new ones and then Nick gave some used ones. They weren't the most used possible but used enough to be compared. It was really interesting to me how the core changed colors so much even though it all broke about the same.
After Publishing Thoughts
If I was working in a tree with a chainsaw, I'd want 2 just in case it got cut. There is more than MBS to think about. However, it is shocking how many comments talk about these bridges breaking or breaking on them. There is also great feedback about the core material in the comment section. I do appreciate how engage the arborist community is and hope that I have more time I can devote to this channel to HowNOT2 in the near future.