Learn me zip lines

I I don't wish to live here forever, but I know I will be kicking myself in the future if I don't use this opportunity of a half acre of woods behind the house to do some ziplining.

I think I have the basics down, like 12" diameter tree, 3'+ clearance on either side of the line, 6% drop, etc., and I have found a bunch of sources for 100 - 200 foot kits, sometimes for under a dollar a foot, which was the rule of thumb I was told to expect, so that's cool. 
One thing I'm wondering about though is if I made a 100 foot level line (besides droop), would a 60 pound child be able to get all or most the way to the other side with just a little jump/push and the droop of the line in the middle to give some initial speed? Ideally, we would have a line that you could ride one way or the other over the ground, but having not heard much about this, I get the idea that's not really possible.

also, I don't wanna leave it up when we are not around, so do they have easily detachable carriages?

If you do make one that will travel all the way to the tree: A) Put a stop on the cable before the tree, B) Instruct your child to let go before the tree, or C) Do both. The first time my son zipped down the line he went splat on the tree. He was pissed

Maybe stretch a cable between two trees at the end point and attach the end of the zip line to the center point of  that cable? 

At least there won't be a tree in the way to knock their teeth out if the rider doesn't let go soon enough.

Probably will need multiple turnbuckles to tension up everything.

The usual factor of safety for lifting humans with cable/wire rope is 10 by the way.   

P3PPY said:

One thing I'm wondering about though is if I made a 100 foot level line (besides droop), would a 60 pound child be able to get all or most the way to the other side with just a little jump/push and the droop of the line in the middle to give some initial speed? Ideally, we would have a line that you could ride one way or the other over the ground, but having not heard much about this, I get the idea that's not really possible.

also, I don't wanna leave it up when we are not around, so do they have easily detachable carriages?

A level line will leave the kids stranded at the 2/3rds point every time.  There is more friction in the trolley than you think.  Also, are you proposing a zipline like at the playground that's just a handle and a cable?  Or are you proposing a zipline like put the kid in a helmet and harness and climb a tree.

Are you thinking that you don't want the liability when you're not around?  Zipline cables are super tight and weigh a LOT.  I can't think of a practical way to uninstall it without a full process - come-alongs, winches, ropes, sweating, etc.  Is there maybe some way to attach some kind of collar lock on the cable so it can't be used without the key?

So... which kind of zipline are we talking about?

This one:

Or this one:

Don't know anything about Zip Lines. However, having zip lined all over the world, the one in Kauai was one of my favorites..

In reply to Curtis73 (Forum Supporter) :

Not sure which one it qualifies as. Im thinking of wrapping a cable around a tree and hooking onto it with a thing with rollers and a round seat dangling from a rope. Probably the line would be no more than 8' off the ground. 
 

Definitely don't want to disconnect the wire, just the carriage, if that's possible. 

You don't have to remove the carriage if you just padlock it to one end.

Lot of valuable info out on Goggle.  Even fairly easy braking systems to prevent face-planting on a tree.

I got a kit from backyard ziplines ans they just use a big bigger cord to stop at the end. Ours is 150'. The biggest issue I had was my yard is flat and in order to not be too low to the ground at the finishing end I had to have a platform 10' tall at the start end. For kids over 6 or 7 it's not a big deal but you get o es need help. We have a disk swat with handlebars to hold onto a d a safety harness for the little kids so they can't fall out/off. We opted for an au return system,  it is fussy but in looking at their website it looks like they have changed the design, might be better. The old one the reminder jumps teeth and then doesn't come back properly. The carriage pops off easily when you take the carabiners that hold the seat and handle bars. Kids have a ball with it and only  a couple of their friends have fallen off due to not paying attention.  The other thing i.learned is the tree at the start end has about 6'-8' of unusable cable due to clamping the wires together.  I had picked a tree with a nice "V" in itthat I thought would be a good take off spot,but ended up building a tower 10'from the tree. Good luck have fun 

nsxmr2elises2000 said:

Don't know anything about Zip Lines. However, having zip lined all over the world, the one in Kauai was one of my favorites..

Yeah, I tried to install a tropical rain forest and volcano in the back yard but apparently the state of Michigan had a problem with that :/

Go figure

There's a retreat center near here with a zip line that they tension using an hydraulic ram.  They hit a button, the ram goes up, and it puts tension in the line.  When the zip liner reaches the end, the ram retracts, the tension goes out of the line, and the rider comes to the ground at about the ⅔ point.

I don't know if that helps, but if it gives you an excuse to build a remote-controlled hydraulic system then you're welcome!

P3PPY said:

In reply to Curtis73 (Forum Supporter) :

Not sure which one it qualifies as. Im thinking of wrapping a cable around a tree and hooking onto it with a thing with rollers and a round seat dangling from a rope. Probably the line would be no more than 8' off the ground. 
 

Definitely don't want to disconnect the wire, just the carriage, if that's possible. 

Ah, gotcha.  I was wondering if it was like tree-top in the jungle style or "hey kid, grab this and run".  Sounds like it's the second one.

You can get trolleys that are snatch-block style.  Pretty easy to put on and take off.

You may want to add a tag line attached to the trolley so they can reach it to go back to the top after they drop off.

Thanks, guys.

Wae, that's the kind of thing I like to know about, too. Something of how others have done it professionally so I might jury rig it similarly. OR, when a hydraulic ram hits the clearance section of the Hammer Store, I could just do it that way like a pro. 
 

Today I did some more measuring. Keeping a wide berth for wildly swinging body extremities eliminated a number of my hopes, but I've found a number of 100-160' options and a personal favorite of mine is 235'. It starts at a huge pine in the "finished" yard and traverses the valley of my yard to a tree at a similar elevation on the other side, way off yonder.

HOWEVER, the tree on the other end is oval in cross-section and just maybe 12" at the narrowest. If I'm remembering right it's box elder, which I've read is a soft wood but brittle. Any thoughts on that using that one for that length?

i've started researching this and backyardziplines/ziplinegear (sister companies apparently) have their install instructions online which i found useful.  Provides a professional and liability-oriented step by step guide to setting one of these things up for the average non-grm idiot, including easy math/calculation guides etc.

not a canoe, but once i started piecing together a kit i wasn't coming up with anything more affordable than the offerings that the cheaper of those two sites had.

What I have yet to do is figure out starting and ending heights as we actually have too much slope to the property where i want to put it...so the finishing platform will be pretty high off the ground.  and there's a fence halfway down the 300ft route that we should avoid hitting when at full sag so the start platform can't be that low either.

Is there a maple, oak, or other hardwood beyond the box elder?  You could "sister" them with another piece of wire rope so they share the load.  You could even make it look intentional and hang a tire swing on it.

In reply to P3PPY :

To actually reply to this, most of the guidance ive seen recommends a 12 inch tree with no comment on type of wood or root system as long as the tree is alive and healthy. I'd take that to mean that 12" diameter has plenty of safety factor and you're fine with the box elder, but I'm not an expert by any means.

Oh shoot I forgot to get back to this. Weather and stuff got in the way so I haven't ordered anything yet.

Curtis, nothing to sister it to. 
RedGT, sounds plausible to me