Probably think we're a bunch of worrywarts
Ladders against trees are exceptionally dangerous, even a 20 footer. Shoot, I've seen a guy flip a ladder leaning against the side of a house and he was a very experienced painter. He ended up hanging by his arms since the ladder caught a porch roof as it was sliding down across the front of the house. A tree gives no such buffer. Soft ground and rounded trunk makes a ladder less than optimal. If you ever look at a photo of an orchard or pruning ladder you'll see they are extremely wide at the bottom and taper to the top

Good luck whichever method you end up using. Post photos when you're done!
-moss

That's pretty easy to take care of- by tying the ladder down to the tree. You can then clip onto the ladder and lean back, if need be. I've never used a throw bag before, but I'll get something figured out. I'll be sure to post photos when it's done!

If anyone wants to check out my website, it's Sleaddventures.com
I've still got a ton of work to do on it, but it gives an idea of what my business is like. I'm putting up this zipline so I can take photos, make diagrams, etc., for an instruction manual that would go with my zipline kits.
Thanks again for all the advice!

-Nate

Nate,
I have some insurance I'd like to sell you...

Seriously man, ladders are a bad deal, especially what you're talking about doing with it. You can secure the ladder, you can secure yourself to the ladder, but what happens when you loose your footing (because using a throwbag does actually take some coordination)? I'll tell you what. You'll drop a few feet to the end of your lanyard, which HURTS (I know), then you'll dangle out of reach of the ladder, unable to rescue yourself. Soon you'll get compartmentalization, and the toxins will build up in your blood. By the time you do get rescued, which WILL be a dangerous operation, IF you've retained conciousness make sure they don't lay you flat, because all those toxins are gonna dump into your system, and stop your heart.

Seriously, call Tengu, call the folks at New Tribe, somebody'll be glad to come out and set some lines for you.

It's better than the alternative.

Climb Safe!
Leave the ladders in the garage.
Icabod

I would imagine selling zip-line gear a close runner to selling fireworks. Make sure you have lots of insurance for the person who sets it up improperly or if you have any gear malfunction. Zip lines is not nearly as controlled as roped tree climbing.

Everyone has the right to make its own mistakes to learn a new business... so do not discourage the guy from giving it try. If it works... and nobody gets killed or seriously injured then he makes some money. If someone gets killed, looses a limb, is permanently disfigured and loses a limb them he gets some time to think about insurance lawsuits and safety while figuring out how to pay for the damages.
So, lighten up and let the poor guy do his zipline stuff! There are companies that actually sell this stuff . Here is a _link_ to one
http://www.bonsai-design.com/zipline.htm

hehehehe.

Hey, thanks for all the input.
I got a line up with no problems, and have finished the launching platform. It'll probably take me a couple more Saturdays to get everything up. I'll keep you posted.