Zip Line Installation Tips
These installation tips assume that you have already determined the basic parameters explained on our zipline design page.
Zip-line Installation – Top Method
The “Start At Top” method is most common when installing a zip line from a tree house or other platform of a fixed height. You can temporarily attach the cable to the tree or structure that you determine is adequately strong, and then unroll the cable toward the destination. You will have to guess at how high to temporarily attach the bottom end of the zipline. If the ride tests well, then attach the top end of the cable permanently. Then retest. Then install the bottom zipline attachment point.
Zipline Installation – Bottom Method
The “Start at Bottom” method is when you have a landing spot in mind such as a destination platform (as in a zipline canopy tour) and you want to find the appropriate starting height to match. Once you have both ends temporarily set up, you can test the zipline. If the ride tests well, then attach the bottom end of the cable permanently. Then retest. Then install the permanent top attachment.
Installing the Cable
For zip wires on 3/8″ cable, you and a friend may not need special tools to install the cable up to about 100-200′ in length, but the right tools will make it a lot easier. For temporary tree slings, use something thick and soft that will not cut into the tree bark during testing. To tighten the cable, a come along and a special attachment called a haven grip work well. Pictures of these tools are on our zipline installation tools page.
Testing the Zipline
It is a good idea to test the zipline before you send a person down. Use the actual trolley and a weight that is approximately the weight of a person to simulate expected conditions attach the weight and note how low it is to the ground at the low point and how close to the tree (or momentum when hitting the tree) at the bottom. Make adjustments if necessary and then retest. Iterate as often as necessary until satisfied.
Adjusting Cable Tension
The goal with the cable tension is to have a safe amount of sag in the line, but not too much sag. Too much sag cause a sudden drop at the start of the ride and faster wear on the cable in that spot. In the worst case scenario, the rider may hit the ground in the middle. Also keep in mind that cable stretches over time, so install the zipline cable slightly taut and it will stretch into your ideal zone.
Zipline Termination Tips
Some ziplines use large forged through bolts that either have an eye or thimbled eye on the end. Typical sizes for normal backyard ziplines are going to be 5/8 or 3/4 diameter. Make sure to get large corresponding washers. Other ziplines are terminated onto a large strap – this strap should be rated for several times more than the calculated loads because straps will deteriorate under UV and moisture over time. Straps should also be sufficiently large so as not to girdle the tree. Lastly, some zipline installation methods suggest wrapping the cable around the tree. If you’re going to do this, the cable must be kept away from the trunk with blocks of wood, a garden hose, or some other surface that won’t cut into the tree or restrict future growth like cable will. A garden hose may work for a small zipline but not a medium sized one. If using blocks of wood, avoid nailing them into the tree for the tree’s sake.