10 Things You Didn't Know about Camming Devices

In the three decades since spring-loaded camming devices were invented, they’ve radically transformed the notion of what climbs can be led safely. Here’s a little lore about modern climbing’s most revolutionary piece of protection.

1 The essential brilliance of spring-loaded camming devices (SLCDs) is their lobes’ shape, which is described mathematically as a logarithmic spiral. The same curving lines are found naturally in seashells, pine cones, flower heads, and even in the basic form of our own galaxy, the Milky Way. Logarithmic spirals are ideal for camming units because no matter how retracted (or nearly tipped out) the cams are, the lobes contact the rock surface at the same angle. Changing the tightness of the lobes’ spiral can change both the cam’s range and its camming angle. But it’s a tradeoff: Increasing the cam’s angle increases the range, but it also decreases the force exerted by the cam’s lobes on the sides of a crack when a climber weights the device. That means cam manufacturers have to strike a balance between the cam’s range and its holding power.

2 These days, climbers tend to use the word “cam” to refer to SLCDs, but, technically, a cam is any tool that can transform linear motion (like a fall) into rotary motion (the rotation of a piece of pro to wedge it more firmly into place). That means hexes placed in a particular orientation, Tri-Cams, and even Big Bros qualify as cams, even though they have no springs.

3 It’s not completely clear who first developed the idea of applying a curved camming surface—modeled on a logarithmic spiral—to climbing protection. Russian climber Vitaly Abalakov invented a piece of gear that looks very similar to today’s Tri-Cams. At about the same time, Greg Lowe was working on a similar piece of climbing equipment in the States. In 1972, Lowe introduced the Cam Nut, a spring-loaded device with a single lobe and a single stem. In Lowe’s 1973 patent, he clearly articulated the idea of creating a curved device to create a constant camming angle. Lowe’s wobbly Cam Nut— which sold for $3.95—and its successor, the twin-stemmed, two-lobed Split Cam, were never commercial successes.

4 The inventor of the modern SLCD was Ray Jardine, who was inspired by the constant-camming-angle concept in Lowe’s Cam Nut. Jardine, an aerospace engineer by training, had already been tinkering with new climbing gear for a couple of years when he first got a look at the Cam Nut in 1973. By spring of the following year, Jardine’s prototypes—which would later become Friends—were ready for a trip to Yosemite Valley, where Jardine used them to dispatch a slew of diffi cult-to-protect climbs. Jardine, who later became a pioneer of ultra-light backpacking techniques and equipment, used his SLCDs to put up one of the world’s first 5.13s, The Phoenix (5.13a) in Yosemite Valley, in 1977.

5 Early on, Jardine kept his arsenal of new camming devices cloaked in secrecy. Fearing that his game-changing idea would be ripped off, he swore his climbing partners to silence. And the name that his camming devices ultimately would take was born from Jardine’s secrecy. He was known to carry his prototype cams in a blue nylon bag so no one could get a look at them. One day, when Jardine was preparing to go climbing, his partner, Kris Walker, wanted to know if the blue bag of goodies would be coming with them for the day. But since other climbers were around, Walker coyly asked Jardine if he had brought the “friends” with him. The name stuck.