I've been thinking about upping my game in terms of gear and technique lately. This is a Hitch Climber, set up as an O rig, which I've installed on my DdRT system. My climbing line is 12mm Arbormaster, so I decided to use 10mm Ocean Poly for my hitch. Moss mentioned getting cordage by the foot to come up with a custom dialed in length, rather than taking a guess on an E2E splice, so that's what I did for this set up. It turns out the center of eye length on the cord is 32", which gives me a snug XT hitch. DMM recommends an eye splice in the end of the climbing line so as not to interfere with the hitch. Since my line isn't spliced, I used the O rig set up. This way, the line comes through the swivel attachment on my harness, then up, to connect to the biner under the pulley, thus staying away from the hitch. I've also rigged a small accessory biner with a prussic from the pulley to the standing line. This also enables me to adjust the distance, closer or further away from the harness as need be. Since I'm getting interested in the world of SRT and the Wrench in particular, I figure this is a nice segue. The hitch operates well. It'll take a little getting used to; like for instance, as I was going up a small branch contacted the top of the hitch and slid me down a bit. I'm sure I'll be able to make use of it, DdRT or SRT.
I'm still trying to decide my ideal setup, but when I'm experimenting with new ideas I almost always fall back on the hitch climber as my go to setup. I also like the concept of the o rig, but still haven't gotten it tweaked to my liking to be comfortable enough to use it at height. The part of this setup you didn't mention is the ring your hitch is passing through. I vaguely recall seeing this discussed somewhere but can't remember the details. Can you elaborate?
That ring is something I saw on arbtalk. Somehow I liked the look of it, as it seems to introduce a little discipline to the lower tresses. I'm only beginning to mess with it though. The main difference between the VT hitch (shown), and the XT, is that in the XT, the line coming off the bottom of the hitch crosses under the line coming down from the top of the hitch and changes direction between it and the climbing line. So the braid you see in front, would be behind, if that makes sense. I think that makes the XT more stable. I'll try it with and without the ring and post further results.
I have been looking at trying this setup however I have some concerns and can't quite figure out how it works.
The dog clip and friction hitch that "tends" the primary friction hitch, seems to me to be inadequate. The dog clip/hitch does a lot more than just tend the primary hitch: it completes the loop through your harness terminating the working end of the moving rope system. When you pull down on the standing end to make progress the primary friction hitch carries no load. Ignoring friction at tie in, half your weight is carried by your arms, the other half via the loop (working end of climbing line down through harness up to biner, HCP, dog clip, prussic).
If the dog clip/prussic fails, the working end hitch/biner/HCP will all slide around and jam into harness connection point hopefully holding.
Is this expected and understood and considered safe and acceptable?
Also, how does one progress the climbing line?
Do you need the line to run through a biner on harness (as opposed to just running though ring) and another biner connecting working end to biner attached to friction hitch and HCP?
In practice have you found that this is all worth the complex setup?
After trying several times to use the HCP I still find just a friction hitch at arms length so I can pull from below and then push hitch up works best when ascending the line. However once climbing the tree, trying to take up slack is difficult.
I was hoping to try out the arrangement posted here to be able to move the HCP out further for climbing then back in close when in the canopy.