Zip lining logs question.

[Mick Dempsey]

I don’t do a lot of zip lining, but maybe I should a bit more.

The other day I was using the technique on a leaning acacia over some chicken houses.

It went great (sorry no pics) I went up, took the rope and strops and zipped down the branches rigging them behind forks so they were securely held.

When it came to the logs on the way down it was a bit more fraught.

Problem is you can’t get tension on the log, so it drops and you have to hope the strop catches the log, I cut big slots in the logs to help it hold, but it doesn’t overcome the fact that the log is in free fall for a couple of feet and could escape the strop.

I ended up holding the strop tight and pushing the log off with the other hand.

It went ok, no dramas.

Is there some way of cinching it in tight, something obvious I’m missing that the cool kids do?

TIA

 

[paddyvero]

Ive never found it to be an issue, give abit of space between the strop and the end of the piece being rigged. Cinch it up snug though. Might be an issue on smooth bark stuff like Euc. We zip line alot. 

[Mick Dempsey]

Do you have krabs both ends of you zip line strops?

[john87]

2 hours ago, Mick Dempsey said:

I don’t do a lot of zip lining, but maybe I should a bit more.

The other day I was using the technique on a leaning acacia over some chicken houses.

It went great (sorry no pics) I went up, took the rope and strops and zipped down the branches rigging them behind forks so they were securely held.

When it came to the logs on the way down it was a bit more fraught.

Problem is you can’t get tension on the log, so it drops and you have to hope the strop catches the log, I cut big slots in the logs to help it hold, but it doesn’t overcome the fact that the log is in free fall for a couple of feet and could escape the strop.

I ended up holding the strop tight and pushing the log off with the other hand.

It went ok, no dramas.

Is there some way of cinching it in tight, something obvious I’m missing that the cool kids do?

TIA

 

Ok, i am no expert at this sort of thing as you all know, but could you not clove hitch the sling to the log?? Would not matter what sort of sling it was, endless or not. Might not be perfect, but it would be better..

 

john..

[Dan Maynard]

Other way I've seen is put a block on, with a bollard so you can negative rig the log down onto a rigging line first, then tighten the speedline and controlled slide it down that. Advantage being less shock on speedline, disadvantage being have to set a block as well so another rope to faff with.

 

I think in any case you need plenty of height for a speedline as the line is bound to sag with weight in,  which is why we don't get to use them much round here.

[Mick Dempsey]

18 minutes ago, john87 said:

Ok, i am no expert at this sort of thing as you all know, but could you not clove hitch the sling to the log?? Would not matter what sort of sling it was, endless or not. Might not be perfect, but it would be better..

 

john..

The slings/strops are a fixed length, not enough for a clove hitch.

[Mick Dempsey]

3 minutes ago, Dan Maynard said:

Other way I've seen is put a block on, with a bollard so you can negative rig the log down onto a rigging line first, then tighten the speedline and controlled slide it down that. Advantage being less shock on speedline, disadvantage being have to set a block as well so another rope to faff with.

 

I think in any case you need plenty of height for a speedline as the line is bound to sag with weight in,  which is why we don't get to use them much round here.

Yeah, rhythm and quick cycle turnaround is key on making zipping worth the effort, so complicating it with blocks etc. is a no bueno.

 

Height is key, agreed.

[Treetom15]

Usually I would put the sling high enough above where the zip line is choked (assuming it’s tied below on the stem) to pull the sling down and keep it tight. Other option is like Dan said, but you could use something that’s quick to change over (X ring on a Whoopie sling with stitched loop works well!) 

 

If it’s something big, say above 12”, then I would neg rig into the speedline otherwise the forces could put too much strain on the slings or line

[gand]

If the slings are a bit loose I've used a metal figure 8 to take the slack. It can help having more than 1 in different sizes though 

[paddyvero]

9 hours ago, Mick Dempsey said:

Do you have krabs both ends of you zip line strops?

No. Steel crab, ideally kept captive on a loop sling. I just biy long lengths of webbing and tie tape knots. You need a  bit of spare sling from the girth hitch to the crab, or the piece can act like a brake on the rigging line.