How do you build a tent that dangles a thousand feet up off a cliff?

Climbers trust their lives to Kolin Powick’s well-engineered products.

Illustration of a tent on a cliffside
A thousand feet up with a thousand-pound capacity—these tents have to do it all.Pedro Piccinini

Kolin Powick is the Climbing Category Director at Black Diamond Equipment. Here’s his tale from the field as told to Rob Verger.

A portaledge is like a cot designed to hang off a cliff thousands of feet above the ground. Rock climbers sleep on them during multi-day climbs up big bluffs. They’re pretty fun once you get used to dangling. I help ensure that all our portaledges do what we advertise: secure you to the rock face. So, for quality assurance, we take one out of every 200 we make and totally destroy it.

We guarantee the bed supports 1,000 pounds. To achieve this, the cots have an aluminum frame overlaid with burly nylon. Six webbing pieces hang from the frame to anchor it. Each one holds 500 pounds. We test all these weight thresholds with a machine that stretches the webbing until the nylon breaks—usually at around 700 pounds. It’s actually the teeth of the built-​in buckle (which allows climbers to adjust the height of the ledge) that cuts the fabric at that weight. The material alone could withstand 1,250 pounds before breaking.

A lot of the testing we do on the portaledge system is about satisfying our own standards more than convincing customers. I’m the guy who needs to sleep at night knowing that people are also snoozing high up there somewhere, trusting their lives to our product.

This story originally published in the Out There issue of Popular Science.