Zipline tree advice...

Jonmck

New Member
I am installing a 200ft zipline and want your opinion on one of the trees that I will most likely have to use. Ideally, I would use the larger, straight tree that you see behind the “slanted” tree. However, the “slanted” tree is in the way and the rider would clip the “slanted” tree on the way down if the zipline was attached to the larger tree.

The “slanted tree” has a 68 inch circumference.
Roughly 2 feet diameter

The Larger tree has a 11 ft circumference
Almost 4 feet diameter

Based on the below photos and the fact this tree is extremely tall and has lived through hurricanes, etc. and not fallen, do you feel it would be acceptable to use? The zipline force would be pulling it to the side of the slant not the same direction of the slant if that makes sense.

In other words, we will not be putting forces on the tree to pull it the way it is already slanted. It would be putting forces 90° from the slant.
 

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Jonmck

New Member
What height are you installing the zipline at?

What will it be connected to at the other end ?
Thanks for your reply. It will be connected to another tree at the opposite end. I can get that tree’s diameter, etc if needed.

I still need to calculate no more than a 6% slope but am guessing the line would attach around 8 feet from the ground level at top side of trunk which would be roughly 11ft on bottom side of trunk.
 

Matthew Stone

Active Member
Personally, I'd look for some nice trees that will be there a few years to do all that work in. Those look poor at best.
 

Matthew Stone

Active Member
Why do you say they look poor at best??
All the dead wood on the leaner, bark looks rough. Have you done any research on species yet? I got my face smashed in by a branch while felling ash timber this spring. It was a similar sized limb as the heavy side of your leaner tree, never figured it'd break off. Damn near ripped my nose clean off, and I can't breathe through it to this day. Something to consider when planning on shaking trees you're standing under, is all I'm getting at.
 

cerviarborist

Very stable member
If you're in Fairhope Al, you might be able to have a good consulting arborist come out to take a look at it. The ISA Tree Risk Assessment Qualification class is given in Fairhope once or twice a year and the instructor is a pretty canny risk assessor. You might be able to get him to come out while he's in town teaching the class and at least not have to pay travel time on top of the fee for a site visit. Message me if you'd like his contact information.
 

JeffGu

Well-Known Member
Trees on a slope like that are susceptible to uprooting, as the bank erodes. It's always better to choose an appropriate site for a zipline, than to choose a zipline for an inappropriate site. Unless, of course, you have the resources to build suitable structural supports.

The same is true of building tree houses. Straight cherry trees over 16" diameter would be a good choice... a leaning elm tree of any diameter would be a bad choice.

You might look around for someone with a lot of experience with zipline construction before choosing anchor points, as well as a tree assessment. If you explain that you simply don't want to make any bad choices and need an opinion, you might be surprised how many people will stop by and give you some free advice. Many professionals understand that it's worth doing, if it keeps people from unintentionally getting some children hurt.
 

climbstihl

Well-Known Member
I think you could attach to the large straight tree, and use the slanted tree as the entrance point for the zipline to avoid hitting it when riding.
 
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Jonmck

New Member
Trees on a slope like that are susceptible to uprooting, as the bank erodes. It's always better to choose an appropriate site for a zipline, than to choose a zipline for an inappropriate site. Unless, of course, you have the resources to build suitable structural supports.

The same is true of building tree houses. Straight cherry trees over 16" diameter would be a good choice... a leaning elm tree of any diameter would be a bad choice.

You might look around for someone with a lot of experience with zipline construction before choosing anchor points, as well as a tree assessment. If you explain that you simply don't want to make any bad choices and need an opinion, you might be surprised how many people will stop by and give you some free advice. Many professionals understand that it's worth doing, if it keeps people from unintentionally getting some children hurt.
Thank you very much for the advice! I certainly don’t want to do anything stupid and get someone hurt.
 

Jonmck

New Member
If you're in Fairhope Al, you might be able to have a good consulting arborist come out to take a look at it. The ISA Tree Risk Assessment Qualification class is given in Fairhope once or twice a year and the instructor is a pretty canny risk assessor. You might be able to get him to come out while he's in town teaching the class and at least not have to pay travel time on top of the fee for a site visit. Message me if you'd like his contact information.
Thanks - will do!
 

southsoundtree

Well-Known Member
Further, you will need to correctly attach and maintain the zipline to the trees, with ongoing inspection.

Many kits wrap the tree, rather than a through-bolt. Drilling a small hole through a tree can be less damaging than wrapping and girdling.

What zipline kit (?) will you use?
 

Jonmck

New Member
I’m not using a specific kit. I bought 3/8 galvanized cable, two large turnbuckles, cable clamps, etc. For the attachment point, I’m using two cable swings with a swage ends and using tree saver blocks made from rubber.
 

southsoundtree

Well-Known Member
Link?

Don't be fooled by marketing, you won't be Saving A Tree.
Moving the zipline and blocks annually would help. If it won't be used in winter, consider removing it.

Different species of trees have different qualities, and resilience.

Live trees are always trying to get bigger. By the time a person really visually can see compression on the trunk, The tree probably already 'knows' about it.
A bit like noticing an engine is low on oil because it's oddly noisy while running.
 

Jonmck

New Member
Link?

Don't be fooled by marketing, you won't be Saving A Tree.
Moving the zipline and blocks annually would help. If it won't be used in winter, consider removing it.

Different species of trees have different qualities, and resilience.

Live trees are always trying to get bigger. By the time a person really visually can see compression on the trunk, The tree probably already 'knows' about it.
A bit like noticing an engine is low on oil because it's oddly noisy while running.
CLAMPS:
Abimars Wire Rope Cable Clip/Clamp, Thimble, Aluminum Crimping Loop For 3/8" Wire Rope Cable - 304 Stainless Steel https://www.amazon.com/dp/B07YC89JR3/ref=cm_sw_r_cp_api_i_6KEhEb52THMXD

TREE SAVER BLOCKS:
Zip Line Gear Tree Saver Block Kit (for 2 Trees) https://www.amazon.com/dp/B01M4LGMLO/ref=cm_sw_r_cp_api_i_WLEhEbSQ41NF0

TURNBUCKLES
Indusco 93900361 Hot Dipped Drop Forged Galvanized Steel Jaw and Jaw Turnbuckle, 5200 lbs Working Load Limit, 3/4" Threaded Diameter x 9" Take Up, 20" Length https://www.amazon.com/dp/B00CFTX4B6/ref=cm_sw_r_cp_api_i_wMEhEbQ69RJ9J

TREE CABLE SLING ATTACHMENT:
 

Jonmck

New Member
Link?

Don't be fooled by marketing, you won't be Saving A Tree.
Moving the zipline and blocks annually would help. If it won't be used in winter, consider removing it.

Different species of trees have different qualities, and resilience.

Live trees are always trying to get bigger. By the time a person really visually can see compression on the trunk, The tree probably already 'knows' about it.
A bit like noticing an engine is low on oil because it's oddly noisy while running.
Do you recommend a 4ft bolt through the tree instead?? I can try to find something that long. I have access to a drill bit that should be close to that size. The end tree would have a 16 inch bolt.
 
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