Hi everyone, I will start with a quick intro, since this is my first post after lurking for a couple months. I have some EF! and NEST-related tree climbing experience over the years but never really got serious about it until recently. I feel capable enough to set an SRT line, get myself up and around in the tree and get down. But that is using a narrow set of traditional "old school" climbing practices. I am interested in taking things to the next level, getting into rigging and experimenting more with DdRT for advancing on a lanyard. But, while I want to venture into more advanced skills, I am wary of substituting fancy gear and magic devices for important skills. So, I am looking to keep my kit as minimalist as possible, since I would rather practice knot tying and doing things "the hard way" because it makes me feel more capable and confident.

Currently, my kit consists of three Prusik loops (one ascender Prusik, one lower ascender Prusik with a foot loop attached, one additional as backup and for changeovers), an F8 descender, my NT double D saddle, 150' static BWII Plus climbing rope, a basic 12' length of the same type of rope as a lanyard, two cambium savers, half a dozen locking carabiners and a couple screw links. I also bring three shot bags, two 180' throw lines and a DIY pneumatic launcher (spud gun) with a bicycle pump.

The biggest new additions I am interested in making are an improved lanyard setup for advancing DdRT-style while leaving my access line anchored. It seems like the most versatile option is just a 30' or so length of rope and possibly switching out the Prusik loops for split tails.

Regarding loops vs split tails, I can't think of any real advantages to a loop for my purposes, other than the (approximately) doubled breaking strength of the loop (minus the DF knot). Right now I use a standard loop (8mm cord tied with a DF knot) that is girth hitched to a carabiner and then attached to the climbing rope with a closed Prusik hitch. I am thinking of changing this out for an open hitch setup, using a 6" runner girth hitched directly onto my saddle's delta screw link with a split tail connecting the runner to the climbing line using a scaffold knot on the runner side and a Swabisch Prusik with a stopper knot on the rope side. I am not sure if open hitched split tails are equally suited for SRT ascender duty, but this seems to me like it would work. I hope all that was clear. Haha, I just enjoy the fact that I am now versed enough in all the terminology and abbreviations that everyone uses that I can even describe all this!

The one real piece of gear lust I haven't been able to shake is investing in a pulley or two. But I am trying to hold off on it until I have a better handle on DdRT.

Welcome to TCC!

Split tails give you some advantage over prusik loops, they won't progressively jam up so much, especially when you rest during an ascent. No reason why you can't use open-ended split tails.

For climbing above your SRT anchor a 30' adjustable lanyard is ok on it's own as a double-ended lanyard but 60' is better, gives you more options, especially crossing big vertical gaps.

Let's see this spud-shooter! I still haven't made one but hope to when I can round up the parts.
-AJ

Thanks, AJ!

Do you have a split tail cord preference? My old setup just uses 8mm PMI accessory cord, which is only rated at 14 kN. I figured it was fine to use for life support since it was doubled in a loop. But moving to an open hitch probably requires some "tech cordage". Do you recommend the 8mm Bee Line as a good replacement?

Making the spud gun was super easy and a fun project. I only just recently finished it and I am already contemplating a more compact and light weight version made out of aluminum.

I will have time to take some photos hopefully later this week.

Depends on the diameter of your climbing rope and what kind of hitch. For example if your rope is 11mm and you're tying a Blake's on an an open ended split tail, I'd go with the 10mm Beeline.
-AJ

thanks moss. one more question, regarding your lanyard setup. it seems like you would need a rope sleeve for both sides of the 2-in-1. is this correct? i recall your gear photo only having one installed on each of your long and short lanyards. am i missing something there?

I don't use a 2-n-1 lanyard. When climbing conifers a loop hanging down creates constant rope management problems. White pine is the default conifer in my area and they are always full of broken off stubs, if a climber wants to spend their entire climb working the loop off of stubs and snags below then more power to them. For climbing wild hardwoods I've found enough rope management problems with a loop hanging down that I will only bring up the other end of a rope for making a horizontal DRT traverse. That's my style, everyone's different. 2-n-1's are popular in the work climbing world (you'll see them in all the arb gear catalogs and websites) but that doesn't mean anyone should automatically accept it as the right technique for their climbing. So... that's how I climb "alt lanyard" technique, short lanyard and long lanyard (or main rope) as long lanyard, either way a single tail hangs down from each system. Also... I don't clip my short lanyard into my side D's, it's simply a short rope system (15'), anchored on my harness center point or floating anchor if I'm climbing a harness with a bridge.
-AJ

Well, it took a while but here is a photo of my pneumatic launcher all strapped down and ready for a wilderness expedition. I set a 100+ ft traverse with the launcher from up in the canopy and it worked great. You can fire a straight line with very little arcing and gets the branch without fail on the first or second try. The major complaint is the time and effort to pump before each shot. This is also pretty awkward to do if you aren't on the ground or standing on a tree-sit platform (I use a cheap foot pump, which is the most effective option over even the fanciest hand pump). The other option is to carry a bunch of CO2 canisters and a mini CO2 pump, but this creates waste and is harder to set the precise number of psi you want for the shot. CO2 also changes the ballistics somewhat and I haven't dialed it in for CO2 shots, yet. After studying some ballistics data from the pneumatic spudgun software available at the Spudfiles forum, I am working on a re-design that will be more compact and modular. The new design will feature a 6" long chamber (same diameter as before) and a shorter barrel with a sleeve attachment to an extension barrel that will actually make the cannon even longer than before, when fully assembled, but will pack down smaller (the photo is an 85L pack and the launcher is quite cumbersome if you are doing any off-trail scrambling.

Ok, Moss, here is the deal. I will post details on exactly how to build the launcher with photos and possibly video of it being used for climbing, IF you give me some plans on making your footshot. I just watched that video and I gotta try making one!

What a great piece of gear! And very nice looking, too. Look forward to seeing the plans, as will my antenna launching friends. However, I would not recommend this unit be included in your carry on baggage!

Have fun!
Bob

This is the closest thing I have to plans:
Footshot photos/

Cool device you made. The bulk/weight is definitely a problem for climbers that hike to trees.

I'd like to see a "soft" pressure chamber, mountain bike inner tube inside a sewn cordura container, hose clamped to a PVC stepdown fitting, field assemble with screw on attachment to the trigger/barrel assembly. Would reduce weight and allow you make it inline, no 180 bend fitting at the base of the barrel. Hold it like a rocket launcher, inflated inner tube pressure chamber straight out behind your shoulder.
-AJ

oh nice photos! i am totally going to try and make one. it seems like the ideal option for medium distance traverses. a few build questions, if i may: how is the tubing attached to the pouch? did you stretch the tubing over a knot in the webbing and then tighten it down with whipping twine? what brand/length/resistance of tubing works best for the foot pull?

hmmm i like the "soft" chamber idea, for sure, since it is def the heaviest (and most expensive!) component on my launcher. so i have been thinking of ways to redesign it lighter amd smaller, too. eventually i can see a welded aluminum one that works equally well and weighs less than half of the one i have now. i feel, however, that the rigidity of the pvc is a major factor in the power transfer and so i have a hard time imagining a rubber chamber being effective. my intuition says that the results of a "soft" chamber would be disappointing. which is a good thing, since, if it were to work equally well, then bleeding some air out of a tire valve would be an explosive experience. i imagine going over to my track bike tire, pumped to 160 psi, pushing on the presta valve and saying goodbye to my finger. but hey, i am no physicist, maybe there is something i am not considering?

I would think that the pressure in the chamber is the determining factor for performance.

You might not be able to obtain as high pressures as you'd like because of the construction of the chamber, but the rigidity of the chamber wouldn't affect the performance.

Though I'd imagine a really good constructed soft chamber would be able to safely hold more pressure than a PVC vessel.

awesome concept for a footshot!
I'd be too worried that I mis-aimed the throwbag and that it break one of my toes! Steel-toes to the rescue?

Sounds right but.... have you ever blown out a tube over pumping? I have, that was a very loud bang about 3 feet from my ear, very impressive release of force. I think the force transfer is the same, the theoretical reinforced sewn cordura cylinder is containing the tube so if say it's pumped to 110 psi, that's what you get when the trigger is released. When you release a presta valve it's a very small aperture, graduated release, all the pressure isn't released at the same moment. With an air pressure gun the idea is that the trigger release causes an instantaneous transfer of pressure into the barrel, right? I don't know if a sewn container can be made hold an inner tube pumped to 110 psi, if it can I think it would work. I believe it's all in the quality/characteristics of the release mechanism.

I'm thinking aluminum barrel would be good though, I've been looking at specs for aluminum pipe and tubing, trying to figure out what wall dimension is needed to be durable enough.

I'll dig up the specs on the footshot tubing and give you some construction details later.
-AJ

Not to worry, toe isn't in danger, it would be difficult to pull the slings back AND at a high angle pointing down enough to hit your toe. Normal operation is to pull the slings straight back parallel to your leg, toes are happy. It helps to be wearing a boot with a stiff enough sole, I can do it with my light/soft hiking shoes (not in the photo) But it's more difficult to keep the upper part of my foot vertical at full pull. I tried once with some pointy smooth leather shoes, no go, slingshot tried to slip off the foot. Still worked but was a bit sketchy. With a decent light hiking boot it's very secure. I've improved the strap buckles to metal. I had one of the plastic buckles eventually break, found that in a pre-firing inspection, didn't cause me any trouble.
-AJ

Oh yeah! The trigger release speed is what I was forgetting. Ok, I will make a prototype "soft" chamber and let you know if it works. I am just going to salvage an old nylon daypack and let my seamstress friend go to work on it. I think a 4" x 8" tube will be ideal. I wonder if there is super heavy duty rubber cement for cutting the back end of the bike tube.. maybe there is a rubber friendly epoxy out there.