Speed line and stem pieces question.

[Mark Bolam]

@RC0 what’s the answer mate?

I’d go with Carlos 2 system answer, but I can’t say I’ve ever done it.

[paddyvero]

If you are taking chunks onto a speed line of a size that makes you wonder about the safety, Id say the chunks are to big. I wouldnt be comfortable with the 2-1 effect of a base tie in that situation. 

[scotspine1]

5 hours ago, Dilz said:

more looking for confirmation on this question - but -  it relates mostly to when having to drop stem pieces on a speedline when the line is set on the stem (i.e just below the chog about to be pushed) 

 

Instead of tieing off the speed line rope using a running bowline or timber hitch at the top - would a base tie and running the rope through a ring on a whoopie sling or similar at the top allow for greater energy absorption due to the increase of rope in the system?   

 

To me it makes sense and tomorrow i will try it out .  I also think the forces will be better distributed rather than everything focused at the top.   

 

Used slight variations on this many a time over the years. The fundamentals here are the best way to do it. I wouldn't be dropping timber onto a pre-tensioned speed/zip line. 

 

 

 

 

 

[TTownsend]

Never was to big of a fan sending large pieces on a zip wire but then I saw this video 

 

[RC0]

4 hours ago, Mark Bolam said:

@RC0 what’s the answer mate?

I’d go with Carlos 2 system answer, but I can’t say I’ve ever done it.

I wouldn't bother with the tie off at the bottom of the tree unless your intending to catch the log with a seperate system, then winch up the zip line so you can send each load out to the maximum distance away, controlled zipline in otherwords. 

 

Putting the redirect from the top to bottom is better for the rope, but not so good on the stem, as others have said. Breaking the stem by side loading is a bigger concern than breaking the rope, if you had to choose one over the other.

 

Re: Side loading depends on the line angle. For an uncotrolled zipline, If you start as a vertical, the forces are nonexistent until the log hits the ground at which point it will jolt the line, depending on how it bounces. At 45 degrees, you'll perhaps still only get a slight wobble on the tree because its still basically free falling with a little bit of guidance from the zip line.  At 90 degrees youre obviously starting to side load the stem a little, but the rope will stretch, as will the stem bend, so it wont really be 90 degrees even if you set it up that way. 

 

Beyond that angle, cut smaller. 

 

The lad who mentioned the rigging device as the tie-off at the landing has the right idea. 

 

Its actually way faster than conventional negative rigging, so long as you have somewhere to land the logs. Start small so you can gauge the deflection in the stem and stretch in the line. Rigging rings are good for this because they can't get misaligned. Good luck 

[RC0]

Probably worth a mention is a guy line on the back side as an extra measure you could add....for a heavy top on a whippy or suspect stem.

[Mark Bolam]

Wouldn’t beyond 90 degrees be sending the pieces uphill?

[tree-fancier123]

if the system doesn't look elaborate enough an 8mm fetching line could be added if using pulleys or rings to slide lumps down on

[carlos]

11 hours ago, Mark Bolam said:

Wouldn’t beyond 90 degrees be sending the pieces uphill?

reg is pretty bloody good, so you never know!

[Mark Bolam]

He looks like Jesus mate, but that’s taking the piss!