Hi, I don;t know if this is the right forum for this topic, but I am looking for advice on building a backyard zip line as follows”

-106′ between two trees (pitch pine) over flat ground. So I would install starting point of line higher up on one tree than end point of opposing tree.
-I plan on tying around the trees on both ends as opposed to a bolt through.
-I would like both children and adults to be able to use, so need something rated for 250+pounds.
-Looking at some of the kits for sale at various websites.

So here is my wish list:
I would like a kit that has everything, but the cable lengths offered are 75′, 100′, 150′. Distance between tress is 106′. By everything I mean, extras like harness, seat, brake block, etc.

I would like to use a gravity stop type braking with a stop block for safety. Although one kit (Alien Flier I believe) offers a trolley with a trigger style brake built in, which is appealing.

I would like a detachable trolley with closed top, so if someone happens to grab the top of the trolley while in motion they won’t injure their hands.

So I’m not sure if I should piece a kit together separately, or buy a kit and cable separate, or if their is a complete kit that has everything I need. Budget is max $400, ideally.

Also, are the trees I want to use ok for this? Pitch Pines tend to sway a lot in the wind, so not sure if they are even the proper tree to begin with…

Thanks for any suggestions, and if there is a better forum out there for this please let me know!




Answers:
1. Before you buy gear you need to have an understanding of the amplified loads on the ends of a zip line. In some setups the static load can be multiplied by factors of ten twenty thirty! The gear might not break but what about the anchor points

Do a search here for zip line or speedline loads. You’ll regret not doing your engineering if the trees break

I’m already looking at two slightly larger diameter trees with a 75′ run as opposed to my original scenario anyway, because one of my first choice trees does not seem hardy enough. Although I have to say, I’ve never seen one of these pitch pines fall over in any type of high wind weather.

3. Ziplines properly installed will often only have 5-6 percent drop for the entire span. They use the curve of the line for the acceleration and braking. 

My suggestion?  

Don’t limit yourself with a budget. Build it right or don’t build it at all. One person’s health insurance deductible is at least 10 times your budget to build your zipline.

4.  There are actually cheaper budget kits out there. $350-$400 range seems to be for decent quality. The cable length is what increases the cost of the kit, so from what I can tell a 75′-100′ kit with quality components and a weight limit of 250-325 pounds is right in my budget range.

5. Well, in researching all of this I read that a bolt through is more damaging to the tree than wrapping the cable. One is permanent the other is not. One way allows for adjustment to how high the start or end point is, the other does not. I would use block spacers between the cable and tree if that makes a difference. Obviously I would not want to kill the tree. You can also adjust the tension of the cable around the tree as the tree grows. I’ll try to get some pics up, thanks for the reply!

6. Having been an arborist for years and also having experience installing ziplines, I would recommend through bolting. Far less damaging to the tree long term. I would really say it depends on the longevity of the line though.

To compare zip lines check out www.ziplinestop.com and their blog at https://www.ziplinestop.com/blogs/zip-line-how-to