Slacklining originated in Yosemite National Park, where rock climbers walked on chains between posts for fun as a balancing trick. It is now a popular sport that has evolved into a popular form of gym equipment as well as a fun way to pass the time when camping. Simply put, it is similar to tight rope walking but is almost always placed close to the ground and the line itself is 'slack'. To a casual observer, a slackline looks like a springy rope, but in reality it is flexible nylon webbing set between two ropes. Usually pulled tight between the two anchors, the webbing stretches when stepped upon, providing a fun and safe way to enhance balancing skills and perform tricks.

Typically, slackliners select a specific variety of nylon webbing for its tensile strength and flexibility. Usually a thickness of 1'' is used for comfort and safety, although ropes of .5'' and 2'' diameter are also used to make it more or less challenging. Flat nylon is moderately light and fairly thin, but can still be strong enough to support 6,000 pounds of tensile strength. More expensive, but the preferred choice of veteran slackliners, tubular nylon holds up under wear and tear far longer than flat nylon. Despite its name, it also feels more 'flat' underfoot than the aforementioned 'flat' nylon, as the tubular shape compresses into a sturdy and reassuring flatness when walked upon.

There are a variety of rigs or setups for slacklining. Since this activity requires tension as well as anchoring points for the slackline, usually some machinery is involved. Everything from expensive hydraulics, ratcheting levers and pulley systems with carabiners may be used to deliver the tautness required for a safe platforming line. But some people just use something like volleyball poles to secure the webbing and walk across.

The most common and usually inexpensive setup is a primitive slackline, named usually for the simplicity of its components. Usually two to six carabiners and good quality nylon webbing form the main line and tensioning system. It can be upgraded into a more powerful pulley system with items such as ascenders and static rope. Other variations will always include some sort of mechanical advantage, such as boat winches or gearboxes, though climbing gear is the norm.


slacklining


Seemingly a lot of work for a balancing act, the tension in a slackline is crucial. Perhaps a contradiction in terms, the slackness of the line is named for the flexibility of the nylon webbing used and not for the line itself which must be stretched very tightly to compensate for friction and weight. This is why mechanisms such as levers and pulleys are generally used, along with a fair amount of human labor, to set up a good slackline. The nylon webbing itself must be inspected before and after each practice, to be inspected for signs of wear and must be replaced regularly.

For a primitive setup the nylon webbing is looped back and forth through the carabiners, with each loop doubling the amount of pull strength. The tradeoff of a primitive setup is that while the materials are less costly than a pulley or ratcheted system, it also requires more manpower (more people pulling to tighten the line) more frequently to maintain the tension. Many view this tradeoff to be worth the time and energy. The cost effective equipment is definitely worth the price for the payoff; an engaging and challenging sport that shows immense variety and scope for the future.