zipline - swinging limbs

[RC0]

Watch in HD setting. The video shows a controlled zipline, with the incentive being to maneuver/swing branches out of a confined area into a more open dropzone.

 

In order for it to work you need to adhere to several points - The first is to establish a high-rigging point and an unimpeded (or as good as) route from the zipline to each individual limb. This usually means starting/removing the limbs around the rigging point and systematically working downwards. The slings are positioned between halfway and two thirds along the length of the branched....which gives them support as they swing around before breaking free from the main stem. The ground anchor must be as far away as possible in order to guide and support the limbs as they swing around. The ability to take up slack at the ground anchor is a must....again to guide and support the limbs as they turn.

 

The limbs on this alder were not heavy, so Bob the guy on the ground was able to muscle the line and manage ok. For bigger limbs though more help would be needed, or perhaps incorporate a 2 or 3:1 mechanical advantage to compensate for the extra weight. Big or small tree though, the principle of the technique remains the same. This was not a big tree by any means, but we made light work of it as you can see, and were easy able to turn the limbs 180 degrees at times. Footage is a little weak at first but gets better. Thanks

 

[chrisj]

Thanks for that RCO. I've not done my CS41 yet so that has really helped me understand what a zipline is all about.

[Stubby]

Oi oi then Reg . Fore arms are looking strong in that vid bud ..... Don't get old !!!

[Jamie_tardi]

Nice. Really controlled descent especially of the lower limbs with the other line, good quality video too. Top job

[Philmypower]

Top job, enjoyed watching that.

[edwood]

Interesting stuff, I've done a couple of speed lines lately, I've always started from the bottom and worked my way up but clearing round the anchor point first makes sense. Do you find when starting from the top on bigger stuff they can sit/get hung up on the limbs underneath? Or is it a case of go smaller and keep the line tight? Either way nice vid!

 

 

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[Rich Rule]

Nice vid Reg.

 

How are you finding the Spiderjack?

[BrendanTreeFeller]

Nice video & nice technique :-)

Is the saw a Husky T540XP ?

[jomoco]

Berry berry nice matey!

 

Jomoco:001_smile:

[RC0]

Thanks guys

 

Stubby I got my 'old man' strength when I hit 40, so all is good. Hope it lasts.

 

Ed, starting at the bottom works just fine and there's obviously going to be no hang-ups as a result....but you need to have plenty of air-space down below. If Id done that with the alder in the vid, say butt tied them, they wouldve just folded and hit the fence or roof and no further down the zipline. But to work the tree in an order where the zipline goes from a high-point unimpeded to each limb and attached at 2/3....the limbs are then supported which allows them to keep their original position but take a change in direction. Same as conventional rigging, using a high-point. The difference is with conventional rigging the limb with swing and then hang only as far out as the high-point, where's with a zipline it will continue out in the direction of the ground anchor. About things getting stuck starting at the top....its your own fault if it does so choose your order thoughtfully. Otherwise just make sure its not so heavy that you wont be able to free it up. Consider also that as you gradually work further down the tree the ground worker gains a mechanical advantage by just pulling on the line which adds to the ability to drag stuff clear from the canopy, just by pulling on the line. It quite something when you see what two guys pulling can achieve even. Hope that makes sense.

 

Really like the SJ Rich, took me a couple weeks to get used to the cams though.

 

Yes it is Brendon, thanks.