Hello backcountry pilots,
I'm building a 400 foot zip-line from our Clear Creek house over a blackberry covered 35 foot cliff, swamp, tree stumps, and Clear Creek to my airstrip. What could possibly go wrong?

Anyone have experience with zip-lines?



James
Clear Creek, Idaho

You have an STC for that thing?

Gump

James, I absolutely thought you were BS'n when I read in the Trees On End Of Runway thread... "the future site of my 400 foot zip-line "what could go wrong?"... and being consistent with the irony of creating an obstacle near your own runway, you sure had me going. I thought to myself, good one. Now I find you are serious. Well, if its not in your way it sounds like a blast. Will you run this commercially to finance the flying?

Mmmmm, I'll ask Hugh Jackman when I next see him, watched him use his face as a brake when he zip-lined into the Oprah show at the Sydney Opera House. Is this like a bat-pole to get to the Maule quicker?

I just built a lower-octane one for the kids. Looks like you have a pulley-system already. Petzl makes some good ones with high-speed sealed roller bearings, and some with steel sheaves to take the abrasion of your cable. Be sure to look at their "speed" variety. And I would personally use a full-body harness instead of a sit harness. Helmet is up to you I guess. Have fun!

Oh yeah-lengthen that blue runner so that there's no risk of fingers and/or hair getting into the pulley. And what's your arrest mechanism look like?

denalipilot wrote:... And what's your arrest mechanism look like?

Zip Line Police.

GumpAir wrote:You have an STC for that thing?

Gump

Hey Gump and backcountrypilot freinds,
This is strictly an owner operator, experimental, field approval zip-line apparatus. I am improving on a few things by safety wiring the turnbuckles, and replacing some of the hardware with hardened stainless steel. Lock-tight on all the bolts will make me feel better too.

The brake system is a solid plastic block sleeve attached to the cable then tied off to a bungee. Hope it works. I plan on sending a 200 pound duffle bag of rocks down the line the first few times as a un-manned zip-line test pilot.

Anyway I'll have more pictures and updates in the near future. Wish us luck.

James
Launch site:
Landing:

James
What is the useful load going to be?
Just wonderin because I might come visit!!
If I do I think you should try a bigger duffle bag!!
Is that 1/2" Cable?
GT

I made one for my kids, only about 200' long, used .75" nylon rope from Denver window washers. Worked great for them. No brake or anything.

Super-Maule wrote:Anyone have experience with zip-lines?

My experience is limited to riding them, but some aspects of the rigging are probably similar to the kinds of work these guys do. Maybe you can track down the forums where these kinds of folks hang out?

Hey James....... To hell with the 200 pound duffle bag of rocks ..... I will ride it down to prove your idea is valid.... ..

Of course, this is coming from a guy who has NEVER been on a zip line..... Like... What can go wrong >

That looks like a lot of fun!

I have built several Ziplines using 5/8 cable and have seen what happens when anchors fail (landed in water). It is easy to see how 200 lbs will pull down on the anchors but the tension in a suspended cable can easily be greater than the load. The more tension you apply to remove sag in the cable will also affects at what angle your load (you) is suspended.

Here's your example:
load 200lbs
cable length 400ft
Sag 20ft
The tension required is 1004 lbs.

If you find that your are landing short and crank the tension in the cable up to reduce sag to 10ft your tension increases to 2000 lbs.

I have seen the back end of a pickup truck get pulled around so plan your anchors carefully, good enough usually isn't.
Good luck and have fun.

Stol wrote:Of course, this is coming from a guy who has NEVER been on a zip line..... Like... What can go wrong >

I'll hold your beer for ya!

Gump

Don't go over 8% slope. I've made a few out of spare stuff, like garage door pulleys, a set of handle bars, springs, and a wore out chock. The kids like the handlebar setup and I took an old pneumatic wheelbarrow tire, ran an eyebolt through the center and connected it to the handlebars with a rope so you have a cushy seat. For a stop, I bought some springs that were about a foot long and 3/4 inch diameter, and quickly wrapped them around the cable. The front of my ghetto garage door-pulley's-sandwiched-between-plywood-trolley-beanered to handlebars has a fender washer on the front of it that catches the springs and starts bunching them up. I think I ended up with about 6 springs on our run. It's amazing how much a few inches of slack or tension changes the speed and then how much it can change on a cold day. A bicycle brake works good for us because we had handlebars to fasten it to, some people just wear a welding glove.

M6RV6 wrote:James
What is the useful load going to be?
Just wonderin because I might come visit!!
If I do I think you should try a bigger duffle bag!!
Is that 1/2" Cable?
GT

George,
3/8 inch cable and the trolley is rated a 350 pounds. Spoke with a well known ski lift engineer from Spokane about my zip-line and got some good tips too. I'd sure like to see your Wilga parked at Clear Creek someday.

James

http://www.thezipshop.com/

Made here in Boulder. Know folks there.