Escape Systems

Hand drilling an emergency anchor

If you’re climbing a little-traveled big wall, or venturing into soft-rock climbing areas like Utah’s San Rafael Reef (see story on page 34), you may want to carry an emergency bolt kit—and know how to use it. Here’s the lowdown.

THE BOLT KIT (fig. 1)

A basic bolt kit consists of a hammer, drill holder, drill bits, blow tube (a short length of 1/4-inch plastic tubing), nylon hole brush (try a test-tube brush), correctly sized wrench for your bolts, and slings and rings to rig your anchors. Carry everything but the hammer in a sturdy satchel that can be rigged for hauling or clipped to your harness. Climbing bolts should be stainless steel and 3/8-inch or 1/2-inch in diameter. For hand drilling in solid granite and other hard rock, a 2 1/2-inch bolt is appropriate. In theory, longer bolts are not much stronger than shorter bolts, but they sometimes reach through a soft outer layer to firmer stone. Rarely, bolts fail by “dinner-plating” off a chunk of surface rock, and a long bolt makes this less likely. Most significant, hand-drilled holes are inherently sloppy, especially in soft rock, and a deeper hole tends to be tighter where the bolt grips.

Wedge-style bolts, such as the excellent Fixe line, are simpler to use and stronger than sleeve bolts of the same diameter, as long as the rock is hard enough for them to tighten. In soft rock, 1/2-inch-diameter Rawl 5-piece sleeve bolts are the anchor of choice. Even if you choose to use the faster-to-place 3/8-inch sleeve bolts for sandstone, all soft-rock bolts should be at least 3 1/2 inches long. Just as you would not lead on the cheap, spooled nylon cord from the next aisle over, never use generic hardware-store anchors for climbing.

Sometimes, in very soft rock, no mechanical bolt will tighten properly. Then, just as in the early days of desert climbing, angle pitons driven deeply into drilled holes become your weapon. “Drilled angle” anchors are directional; just like a nut, they have little direct pullout strength. This makes them dangerous when treated like conventional bolts, and because of this they have fallen out of favor. Nevertheless, a few angle pitons up to 3/4-inch, carried in addition to your standard bolts, can save the day in super-soft sandstone.

The bits in an emergency drill kit should be brand new and sharp. I carry a drill that accepts SDS bits, for ease of bit change-out; other systems use easy-to-lose set screws or jam-prone tapered shanks, and the bits are harder to find. Regardless of shank style, look for a rock bit with a pair of carbide “wings” at the tip, with the fluted portion of the bit slightly thinner, so the bit doesn’t bind—a serious problem when drilling in hard rock. The downside of a “wing-tip” bit is that it wobbles more easily, risking sloppy holes.