Let's Talk Highlines
My only exposure to highlines is RRGTV, so I find myself with a lot of questions. Now sag in the line seems to be a critical element. The more sag, the less load on the anchors, but with this also seems to come a price which is too much sag will make it impossible to bring the patient and rescuer to the retrieval point. So what is the ideal sag which does not load up the anchors, yet allows a safe patient retrieval? Hope that makes sense.
RRGTV is a great resource. However, the videos only show a small part of the lecture. I'm sure Pat is not in the business of giving away too much info for free. He likes to cable yard for sag. You could use the rule of 12s for 7/16, or rule of 18 for 1/2". Number of haulers times MA not to exceed 12 or 18. Most of us simplify the process by only applying pretension to the highline with one person pulling on a 2:1. If you need to clear something add a 3:1 and another hauler. This tension method will also keep your numbers above a 10:1. If things are a little outside of the norm, you would need to know when to add additional track lines to keep your SSFs up. With highlines there's a lot that can go wrong. It's helpful to know someone with a load cell as you practice. Otherwise you can get yourself into trouble very quickly.
Your retrieval point is the same regardless of the amount of sag in the rope. It's going to point the point where you're unable to pull the carriage past on the trackline. It is not impossible to haul a load up to the retrieval point, you just put a haul system on the horizontal control line.
Originally Posted by MichaelXYZ
Sag will cause a problem if there is something (water, rocks, etc...) in between your two highline anchor points that you want to clear. It is then that you have to provide more tension or possibly add more tracklines.
I get what your saying. BTW I thought your use of the Gin pole in the atomic wedge was real cool. Have you guys tested that with data?
Thanks! No tests yet; I'll be doing some in the coming months, though.
I hope you share your test results on your website. I can see the application of your AW in the industrial sector (albeit as infrequent) as well as urban.