So there is nothing inherently wrong with using an old climbing line as a rigging line, but you do have to make sure that it gets moved permanently to the rigging category. I'll use the tail of my climbing line to lower stuff that i could control by hand (without a dynamic load) and nothing bigger, but some folks would look cross-eyed at even that.
You many not imagine using/needing more than one climbing line now, but i would be perpetually irritated w/ just one. Some of it depends on where you are, what kinds of trees you have, and how tall/wide they are. I'm in Philadelphia, and I could climb a 14' snowbell, a 25' kousa, a 40' Japanese maple, a 60' pignut, a 75' beech, a 90' red oak, and a 115' tulip poplar, maybe (hopefully not, but maybe) all in the same day. The tulip might have the same spread as the kousa, but the oak and beech might be wider than they are tall, and I could be out twinkle-toeing in the tips, or i could be ripping them down, maybe with a crane on the larger ones. They all call for different styles of climbing, and different styles of climbing call for different types of ropes. I have:
-an 11mm 200' kernmantle (workpro) that is my big tree pruning rope, and is used almost exclusively SRT. Love using an easily adjustable base anchor to control the lenght of my tail when i pull this out. (not really an appropriate rope for DdRT, might do a quick tail-tie double crotch for positioning, but that's it)
-an 11.7mm ~180' double braid (Yale 11.7, same as blue moon) that I use for crane work (requires DdRT) and not a whole lot more these days, honestly. Kind of wish it was spliced.
-an 11mm (wish it was 11.7) ~90' double braid (velocity, gonna replace it w/ voyager when it wears out, bit still love velocity) with a splice that is probably used more than anything else on the truck. It's an 85' canopy anchor line if I use a pull-down line, It's a medium-tree Ddrt line, and most frequently, it's a second system used in conjunction with my long ropes, almost always DdRT. A long, central SRT line and a shortish DdRT line is awesome in big spready trees. I also occasionally have call to use it as a lanyard, usually on truly large crane removals, as my daily driver lanyards are 22' and 16' double-ended jobs, so when the wood starts to get to big for my 660, it's getting to big for my lanyard. I want to replace it with something a little thicker because it mostly gets used DdRT, and I climb bare-handed. I love how small and light velocity is and how well it works in hardware/ascenders, but it's a little hard on the paws and isn't really compatible with my zigzag.
-an 12.7mm (half inch) 16 strand about 35' or 40' long. Small tree/ladder backup rope, nice and fat for hauling on Ddrt/muscling around. I don't find 16 strand's stretchiness to bother me when it's this short. Wish this one had a splice, too. Also gets used as a second system sometimes.
Having ropes of different lengths makes tail management much easier. If i had to use even a 150' rope in a 20' tree (or even a 35'er), I'd probably murder someone. Double crotching, however you do it, is an extremely powerful technique. Someone is probably going to chime in and say it's a crutch, but I'm a regular person not a NFL cornerback, I'm heavier than most climbers, and I'm middle-aged, so I prefer to think in terms of longevity and comfort.
Ropes get called a lot of things when they're getting sold. Just because something is labeled a climbing line, an rigging line, a prussik, etc, doesn't mean that's all it's good for. It's better to think in terms of rope construction and behavior rather than what category they're under at Treestuff or Wesspur. In general:
- double braids are strong for their diameter, handle natural crotch at human-size loads OK (the Yale 11.7s wear like iron as climbing lines) but do very poorly at heavier loads, then they really want hardware to run through. They also milk.
- 3 strands rotate under load (PITA), hockle (giant PITA), don't really work at all with ascenders and new-school climbing techniques, they're pretty stretchy, and they hockle. However, they are light, cheap, easy to splice, and are the natural crotch champions of the world. Also, they hockle.
-16 strands are strong, wear really well, handle natural crotch pretty well, medium bouncy (like your hair with Pantene), medium expensive, just kind of the all-around average rope.
-12 strands are bouncy/stretchy, hand natural crotch really well, are strong at 1/2" but their strength doesn't scale up as well as double braids, tend to have good hand, can't be hand-spliced, and are, erm, nubby.
-kernmantle ropes are kind of a mixed bag, but tend to be less stretchy or bouncy, wear pretty well because they usually have tight high-count jackets, but frequently aren't appropriate for Ddrt or rigging.
It's important to understand that breaking strength isn't the ultimate measure of a rope. How elastic/stretchy/bouncy a rope is is really important, too. I don't want a bouncy climbing line, and I'd prefer something on the more static side when I'm lifting something, say with the GRCS or a 5 to 1, but if I'm blocking something and there's no room to run it, I'd love stretch in the rope. So in the above examples, I might choose to climb with xstatic or KM3 max, lift with sta-set or stable braid, and block onto polydyne.
After all that rope-nerd blather, let's address your real issue: having the right gear at right time to continue expanding your skill set. Just as with climbing, start with the basic, tried-and-true, old-school methods. Learn to natural crotch first. Learn to use multiple crotches and switch ends to make your rigging system more useful, flexible, and efficient. That's why people are steering you to 12 and 16 strand ropes. They'll hold up better. I'd take it a step farther and suggest your first rope be a 200' soft-lay 3 strand like pro master. (never buy a rigging rope shorter than 200'. It'll be shorter soon enough, I promise. Just grab a bag for it and don't look back. By the reel is best.) It'll only set you back $90, it's great for natural crotch, and plenty strong for what you'll be doing. When you get to bigger stuff, true blue, buzz, or ogre are 12 strands that are a little stronger (and more expensive), still good for natural crotch, but will play nice with port-a-wraps and pulleys (3 strand will work in them, but again, the hockling). I wouldn't worry about big bull ropes an huge rigging gear until you actually need it. You can remove most small and medium trees with half inch rope, and you can always double block if trunk wood starts getting too big.
Don't buy your whole rigging kit at once, and don't automatically go for the big stuff right away. A couple half inch lines (i recommend bagging all ropes), a medium or large port-a-wrap, an a couple of the half inch green blocks will get used way more than other rigging gear, are cheaper, and are closer to your skill level. Buy stuff a piece or two at a time, and do your best to try someone else's before you buy.
Oh, and of course don't get rid of the safebloc, but for God's sake, get it spliced into a real sling, even if you have to send it out to do so. Also remember when you rig bigger stuff, you'll need bigger more expensive saws, a bigger truck, a mini/swing loader/lots of peons, i.e. Bigger rigging=bigger headaches. Dont be in a hurry to spend money, use what you've got or just a little more to MAKE money, and bootstrap from there. Make tree work pay for itself.
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