I am aware of the swabish hitch and the distel hitch when usin an I2I split tail for drt climbing with or without a pmp . What are the advantages and disadvantages of these knots. What other knots are there that could be used in this setup with or without a pmp?

Here is an example of the one I have used recently without using a mini-Pulley but a Dietley made adjuster. It works very well and similar to the mini pulley.

Oooooh! One of my favourite topics! Be forewarned that there are Luddites here who will slap you silly for dabbling with these horrible arborist hitches. Remember, they are called CLOSED hitches; don't ever, EVER call them ADVANCED hitches or feelings will be hurt, okay?

Now then. The Distel is my favourite of the closed hitches. When I first learned them, NickfromWI recommended the Distel as the best to start with, because it is the most reliable and consistent closed hitch, and therefore a safe place to start. I have played around with several others, but it is still the one I come back to. Good reliable grab, dependable release, and it seems to work well for a long period without needing to be loosened. It's also nice and compact.

The Schwabish is a good hitch, too, but not one I use much. It grabs beautifully, but doesn't seem to tend with a slack tender as readily. I really like closed hitches to start tending themselves once a fair bit of rope is hanging below them, and this one doesn't. If you are going to be tending it by hand, same as you would with a Blake's, then it does the job just fine.

The Valdotain Tresse (VT) is the one that seems most popular with the arbos. It has the easiest release of all the closed hitches, but it can be fussy to adjust so it grabs reliably. It also is the least compact -- it takes up more room on the rope, and after advancing your position, it allows you to drop back down more than the others before it grabs. I don't like it much, but a million arborists prefer it and they can't all be wrong!

The XT is a variation of the VT, and it addresses many of the concerns about the VT. It grabs much more reliably and releases almost as easily. It has a fair bit of "droop" when grabbing after you advance, but not too bad. It's a great hitch, and, I believe, one that Moss uses a fair bit.

The Martin, or Michoacan (sp?) is a nifty hitch that is already familiar to you -- it's a 4/1 Blake's hitch, with both ends of the hitch cord fastened down. Very reliable grab, not bad on the release, but it seems to tighten up on me as I climb.

Another good one is the Knut. It is one of the few closed hitches that allows tending by pulling on the tail of the climbing line WITHOUT a PMD (prusik-minding device). It's my second favourite closed hitch, working quite similarly to the Distel. There is a variation called the TK, which finishes up slightly different (a marl instead of a half hitch). I find the TK tightens up too much after repeated loading-unloading cycles, but that could just be me!

The last of these closed hitches that I routinely practice is the Icicle. Really good grab, not bad release. It's a good one to try when nothing else seems to hold dependably.

There is no such thing as the perfect closed hitch. They all work well with specific hitch cord and climbing line combinations, and all can fail under certain combinations. Heavier climbers will prefer certain types, people who prefer the hitches looser or tighter than others will have preferences. Whether you tie the ends of the hitch cord or have them spliced will also make a difference.

One thing that makes a huge difference to me is cord stiffness. My favourite Distel (as well as the VT, Schwabish, Michoacan, etc.) won't always grab reliably if the hitch cord is stiff. For them, the Knut, TK, or Icicle really seem to shine, but with a softer cord, they will jam easier and not release very well. With a softer cord, it's hard to beat the Distel, although the VT really shines, too.

Pictures of all these hitches, plus evaluations much more learned, are available in a couple of outstanding articles on TreeBuzz. Have fun with these, Glenn, and ignore the jabs and insults from the curmudgeons!

That is just the sort of gadget I have been pondering. Hate to waste a pulley on a lanyard. Is it aluminum or plastic?

They're aluminum, Dave, although plastic would work well, too. They're lighter than a pulley, more compact, simpler, etc, and they seem popular with some of the guys who have them. However, I seldom use mine! Pulleys are more versatile, especially if they are safety-rated, so I usually bring them instead. They are nice on a dedicated lanyard, but it then means you can't use your lanyard for an emergency pick-off strap, as you can with a rated pulley (For an explanation of that usage, check out J~birds article on the Coalition articles page).

Dietley rocked it. Yep, I use the XT exclusively now. I do a 4-wrap XT and have the cord length tuned so there is very minimal "droop". I climbed VT for a while but I always had to nudge it up to get it to set. Agree that the Knut tends to progressively tighten up too much. Any hitch will, some more than others. Typically once or twice over a 3-hour climb I'll loosen the hitch a little, and I always loosen the hitch slightly before a long descent. Also agree with Dietley that a micro pulley is not wasted on a lanyard, can come in handy and can be used to rig a mechanical advantage lifting system for rescue as Dietley mentioned.

4-wrap XT, this is before I shortened the cord a little to get a tighter fit. With these hitches it's best to leave the cord long and test to determine the optimal length per hitch and climbing rope diameter.



-moss

Here is a traditional split tail using a B4-2 knot, you can also use a Michoacan knot with Eye x Eye tail




After I posted it irealized that you were looking for eye an eye tails
oh Well

This is the other knot used on a split tail set up. If the split tail is shorter than one on this photo then the slack tender is closer to the knot.

The Michoacan or Martin is a Blakes 5-2 with the tail tied back to the biner.
Front View


Rear view

OT,

Does the "ADJUSTER" provide an auto-advance for that setup? If not, what purpose does it serve.

Well, Ok, but couldn't a pulley wheel (or plastic thimble) fit inside it?

I suppose a sheave of some sort would fit in there, but I'm not sure what the advantage would be?

It allows the climber to take slack out one-handed (or two-handed) when returning from a limb walk or in an climb situation where the climber wants to quickly take slack out of the system (see page 55 of the Tree Climber's Companion). To do so the climber pulls the tail away from their body against the Adjuster or micropulley. Most hitches will bind if you do that without a pulley or similar device.

Normally a closed split tail self-tends slack when there is enough rope weight below the hitch. There are situations where you want to manually take the slack out, that's where a micropulley or similar device is used as described above.

A well configured closed split tail system is self-advancing by default. The climber stands on the tail with Pantin or footlock and pulls rope above the hitch with both hands, the hitch opens up and rides up the rope as you climb then grabs when you stop climbing and load it. That's the theory, each climber has to tweak their system to get it to work correctly. It's a completely different paradigm than Blake's Hitch climbing where the climber pulls rope below the hitch and moves the hitch up manually per pull or rigs an auto advancer.
-moss

Moss pretty much explained your question.
Yes, the adjuster serves as a knot advancer on the way up and it directs the rope into the knot on the way down. A mini pulley will do the same job not a big difference. I just did not have one of the mini pulleys handy when I was taking the photo.

P.S.
The Dietly Advancer is a sepcial tool and very few people has one so do not worry about it use a puley instead.

I'm just starting to consider serious experimentation with closed hitches. I rigged up a pulley to self advance my blakes hitch yesterday and I was not impressed. It was nice if I was just adjusting my position a little bit, but for climbing I found that it added to much drag to the system. Also, I've been using the A.R.T. Positioner lately and realize that it's just a mechanical replacement for a well tuned closed hitch/pulley combo on my lanyard. I like the way that my climbing style has changed as a result. I would say it feels much more hands on, holding and climbing more tree and less rope. I just need a good full day of nice weather to spend time playing with all the possible setups.

So far I have found out that micro pulley/closed hitch systems tend to have a little "play" in them. In some pictures of VTs it looks like some would stretch out almost a foot before setting. Even the pictures I've seen here of Moss's etc... look like they have several inches of play.

I found that even a tightly tied VT with a pulley, on a carabiner, clipped to the legstrap D ring on my Tengu saddle, had almost enough play in the system to make climbing a futile effort. I would climb up a nice full "step" up the rope. After 6 inches of play caused by the carabiner going from being pulled from above, to being pulled from below the pulley would move up a few more inches, scrunching up the braids in the knot, then it would finally begin pushing the knot forward, then when putting my weight into the saddle I had to lower myself a few inches to take up the slack in the hitch, then several inches as the carabiner flipped up into position. Net gain: 4-6 inches per footlocking step. After quite a bit of time, and a very short progress I slid back to the ground and set up a blake's hitch.

Am I way off here? Or is this a system that relies on not hanging in the harness much between climbing steps? This was when climbing DdRT single footlocking the tail, There was much less play if I was standing on a branch and could take up slack by pulling out on the tail. That action pulls the carabiner up into position first, then there is still the play in the hitch itself. Some hitches I've seen photos of look like there are 4-5 inches of slack in the tails of the eye2eye between the hitch and the pulley.

Carl

P.S. I am a big fan of the "fair-lead" benefits of the micro pulley below the hitch.

Carl, I don't use a VT for that very reason. I prefer the Distel, Knut, or Michoacan, and I have the legs so short that it is a pain tying the friction hitch. Also, I usually employ some means of keeping the hitch carabiner upright even when unloaded.

As you imply, there is a difference in climbing style, too. Because you're pulling the downrope above the hitch, you can take two or three pulls when hip thrusting before pulling the slack through, and, when using a single footlock or foot ascender, you can climb through many strokes without even sitting down in the saddle (now that I think of it, you can do the same thing with a traditional Blake's system too).

As mentioned above, the coolest thing is when you have enough rope weight below you that the closed hitch self tends.