Speed lines, SRT vs DbRT, and Top Down or Bottoms Up?

[treeman82]

I am not extremely experienced with speed lining, however my thought would be that in the ideal situation you would have access to either a chipper winch, or a manual winch similar to the GRCS or Hobbs. Set your speed line once (G-d willing) and let slack out to attach new branches, pretension the load, and then once you have the limb cut, raise the speed line up with your winch. Of course for that to be effective you would need a friction device to control the descent of the limb or log. Relatively cheap.

 

[MasterBlaster]

Originally posted by treeman82
I am not extremely experienced with speed lining, however my thought would be that in the ideal situation you would have access to either a chipper winch, or a manual winch similar to the GRCS or Hobbs. Set your speed line once (G-d willing) and let slack out to attach new branches, pretension the load, and then once you have the limb cut, raise the speed line up with your winch. Of course for that to be effective you would need a friction device to control the descent of the limb or log. Relatively cheap.

No need to turn it into chinese 'rhithmetic!

 

[John Paul Sanborn]

A winch would be nice, but one can tension the SL with pullies and a prussic. I've used 2 at once with a porty, we are waiting for the job where we can use 3 without streaching it.

The control/return line can be run through a pully under the anchor point on for the SL.

A porty can pe placed under the climber (for that matter the climber can run the porty, i've done it) to let the load go down slow. Larger loads can be run this way, but as Mike has pointed out so well in the past, heavy loads can be placed on the anchors.

on returning the line a stopper knot is placed in the line so that the connector is not run all the way up to the trolley pulley.

More often then not this is not applicable to space requirements, or more work then it iss worth. but when it does, it sure saves time and effort.

 

[Tom Dunlap]

Ive read studies done by searcha nd rescue people and they showed that they could never generate enough heat from a descending device to get it hot enough to harm a rope. I wish that I could put my finger on the link but its eluding me right now.

The only place there could be heat damage is when the friction device stops and sits on the rope for a time. A groundie is more likely to get toasted.

There are many variations on SLs. Cut and slide is the most basic. Once the rigger gets experience its possible to start to do lift and transfer setups.

Before anyone goes off and starts setting up SLs you should do some studying. The force amplification is phenomenal. In the glory days of the ISA page this subject was thrashed out pretty well. there is a curren thread on Tree Bu*z with Dave Spencer's Excel spreadsheet. You can plug in some numbers and see what happens to the load forces.

Doing SLs without a good understanding of the physics is a sure way to get hurt or damage things catastrophincally. A good source of information is the ISA-Art and Science of Practical Rigging study guide and video series. This is the best training program available.

Tom

 

[MasterBlaster]

Toms agreeing with me???

 

[TheTreeSpyder]

Welllllllllllllll, every once in a while; you ain't toooooo baaad!

Heck, i'm lazy, i just hit the WWW (WorldWideWrestling?) button under one of Tom's posts, and go right to Tree Bu*z!

On climber's board @ TB for Dave's spreadsheet/load calculator, ya might look for the 5 star rated thread "DWT" (2/1, Double Whip Tackle); for the same chart you use for 'seeing' the leveraged force of loads on a spread apart on supports, loaded dip in the line for DWT, is the exact same as SpeedLines. For the time of learning one, you can learn both, if you link them together. And any lesson/experience you learn/gain with the DWT loads, you can put in your SL "wallet" too! And of course, vice versa.

But, there is a better deal! Any of this harvest from these lessons/experiences can be folded directly into understanding: why not to seat/pound steel chokers down to the wood on large crane loads, how sweating in can help leverage great tightening, cautions in spider legging:Monkey: (never did like the sound of'dat), leveraging steering on limbs with the same angled line, lifting with spread cables, lowering with spread lines, even hanging a hammock etc. With experience with any of these, with this understanding, build$ experience with them all. Eyes opened up, to see that pattern; can flood enough to give greater depth of experience/feel from the awareness of the actual repition around if ya catch the pattern IMLLHFO!

Very much to be gained with these keys; even if it seems to start up a lil'ruff at first; like da'oil is thick or something! Pay the piper, :Eye: do the time....




Orrrrrrrrrrrrr something like that!
:alien:

 

[Hemlock]

Hi everyone. I've been browsing this site lately and have learned alot. Although not an arborist by trade there is a lot of good old logging techniques that you folks use. Speedlining is called shotgunning in the woods. Lots of different carriage types but the basic system is still using gravity on a standing or running tightline to get the work done. I rigged up a small device with a quick release one time for a Log show clown act that worked good. The general idea would be to rig a standing tightline (speedline) and a haulback running through a block on the bottom of the tree and up through another one by your skyline and back to the carraige. The groundman could pay out slack to lower the loads and pull a tripline to release them and haul back the rigging to the climber. This method is used in the woods with "automatic chokers" and it really keeps the rigging moving and boosts production. The groundy would need to have alot of slings on hand to ship to the climber as needed. Would it work?

 

[Tom Dunlap]

Before you click on this link, be sure to notice the evil, nasty agency that's providing the information. Take some time and browse through the site.

This is an excellent article on cable yarding. Like Hemlock said, arbos have gone out and scavenged the tools but we haven't done such a good job of properly training the practitioners in the techniques. Read all that you can about the loads that are generated by these systems.

I had a bit of a problem accessing the page from my Bookmarks. If it doesn't work Google "cable logging systems".

http://www.osha.gov/SLTC/etools/logging/manual/yarding/yarding.html

Tom

 

[Hemlock]

Thanks Tom. A picture is worth a thousand words. Although some of this stuff can get complicated and turn into a hooktenders nightmare, most of the stuff being done nowadays is on the simple side due to the changing regs and newer equipment (I still think that loggers stole most of their ideas from sailors anyway). One of the newest things that is out there that might be of interest is a new line that is being experimented with that combines the best qualities of rope and cable. It is lightweight and low stretch. I first read about it in the Loggers World newspaper and ran into a logger that is currently testing it and it sounds too good to be true. Who knows, maybe the days are here that a climber will need to carry a calculator to keep from biting off more than he can chew!