New Page - Hammock Suspension
I wanted to consolidate a bunch of hammock suspension ideas and pictures, so I made a new page on my site. Have a look and let me know what you think. What should I add? What should be changed? Point out any typos, too.
Here's the intro:
Now that you have your hammock, you have to hang it. But what's the best way? Should you go with the stock method that came with your system? Should you just slap some webbing on there and wrap it around the tree? What's the lightest method? What's the most convenient? There's no right answer to these questions, of course...it all depends on your priorities for what you want from your system. This page gives an overview of several available options. It isn't all-inclusive, but it does provide enough considerations, pics and links to get you started. Let's begin with a definition:
The purpose of hammock suspension is to support the hammock safely without damaging the environment. Everything else - low weight, bulk, complexity and expense - are secondary concerns.
Now let's break this apart:
Support the Hammock... The suspension has to keep the hammock off the ground. This brings a few requirements, and there are options for each that will be discussed below.
- The suspension must connect to the hammock.
- The suspension must connect to the trees (or whatever you're hanging from).
- Since the trees won't always be the same distance apart, the system should be flexible enough to cover a wide range of hanging sites.
...Safely... Hammocks can put hundreds of pounds of force on each support. It isn't simply your weight divided by two...it's a trigonometry function where the cord or webbing is the hypoteneus of a triangle. Using the angle of the support to true horizontal, the force on the support is: h = (.5 x user weight) / sin(support angle). This also brings a few requirements:
- The suspension must be strong enough. Be very careful using cord or webbing that doesn't list a working load or breaking strength. The lowest acceptable range is generally 700 lbs, and some people will not use less than 1000lbs breaking strength. Do not use 550 cord (parachute cord). I've broken 550 cord twice using it on a hammock, and I cut it directly off a parachute so I know it's the real thing.
- The correct knots/lashings must be used. Knots can significantly reduce the strength of cord and webbing. Some knots reduce the strength more than others, and certain knots are designed specifically for webbing. Additionally, some knots will bind when they're weighted and you'll have to cut the support to get the hammock down. So pick non-binding knots or lashings when you choose your system.
- The tree must be strong enough. Trees 6" in diameter are usually strong enough to support a hammocker. Make sure the tree is alive and there are no widow-makers nearby. Some trail shelters are capable of supporting a hammocker...others are not. People have torn door frames out of their homes, pulled their walls out of square and ripped garage door supports from the ceiling by hanging their hammocks from them. Learn from their mistakes.
...Without Damaging the Environment. Given the force on a hammock support, the wrong cord can easily damage a tree. In extreme cases, this could even girdle the tree and cause it to die. This is obviously bad for the environment, and it can encourage restrictive regulations at government-owned that prohibit anything from being tied to trees. Fortunately, this has an easy solution...use tree huggers or webbing on the tree. Anything that spreads the force across a larger surface area lessens the impact on the tree. If hammockers can limit the impact on the trees, a hammocking site is generally more Leave No Trace compliant than a tent or tarp site because we don't flatten the ground.
Secondary Concerns. Once the primary considerations for the hammock suspension are covered, it's time to consider the details of your system. This is where the trade-offs start - more convenience usually means more weight, bulk and complexity. Carabiners are a good example of this - it's much quicker to wrap the webbing around a tree and click the biner on than to use the Hennessy Lash...but a load-bearing carabiners weighs over an ounce each. On a thru-hike, that's 2-4 extra ounces for a couple thousand miles. Only you can decide if that's worth it.
Materials are another consideration. Suspension is usually made from low-memory stretch cord like Spectra or polyester or polypropylene webbing. Low-memory stretch means that, once the material is stretched out from you laying in it, it doesn't remember how to pull back to its original position...it stays stretched out so your hammock doesn't end up on the ground every morning. High-memory stretch material like nylon pulls back to its original position...so you'll end up hanging much lower every morning than you started the previous night. Paracord (550 cord) is made from nylon so it can stretch to absorb opening shock...in addition to not being strong enough, it stretches too much to be an effective hammock support. Slap Straps by Eagles Nest Outfitters are currently made from nylon...many hammockers have tried and discarded this approach because of this. If you like the system, make your own from polyester or polypro webbing.
Two Key Decisions. There are two key decisions to make for your suspension.
- Will you use cord or webbing? Webbing is generally heavier and bulkier, but can be simpler to make and use. Cord is lighter and has less bulk, but also means using tree huggers and knowing how to lash them correctly.
- Will you use hardware? Ring buckles, cinch buckles, figure nines, etc - all can make setup and teardown very quick and easy, but also introduce more complexity, more parts to fail, more weight and more bulk.
Each of these will be discussed in the following sections.