Rebolting is the practice of updating and replacing protection on sport climbing routes. That means inspecting the bolts on established routes, removing any that are too old or otherwise untrustworthy, and installing strong new ones in their place.

Bolts merit this special concern because they're a communal resource. All the rest of a climber's equipment is his own personal responsibility-- from his shoes to his rope to his helmet-- but the bolts are a permanent fixture installed by a stranger. Climbers trust life and limb to the strength of each bolt, so even though the majority are quite safe, the unsafe minority could cause injuries or death.

When a sport route is established, the first ascensionist (or "FA") installs the series of bolts for use by later climbers. However there's no such thing as a license to place bolts, or even a universal class that one is required to take first, so it's possible for the FA to make mistakes. A few potential problems can lead to unpleasant surprises for later climbers.

Sometimes a route will be set up with the wrong type of bolt, which usually means the FA was a cheap jerk. Real climbing bolts are very tough chunks of stainless steel or titanium, tested to withstand upwards of 20 kilonewtons (two tons!) of force, and they cost something like US $5 to $10 each. A cheap jerk may instead go to the local hardware store and buy ordinary machine bolts for a buck apiece. Generic bolts are made of lower-grade steel, are of inconsistent quality, and have lower strength ratings to begin with. When such a bolt is stressed by the sudden force of a hard fall, the metal might simply come to pieces.

Other times the correct bolts are used, but installed incorrectly. Expansion bolts must have the appropriate torque, neither too tight nor too loose. Glue-in bolts must be used with the proper type of epoxy, mixed and applied in the right way. Each bolt hole must be of a certain size, depending on the size and type of the bolt. The holes must be drilled in stable rock, far enough away from cracks or flaws or other holes. If any of these aspects of the installation are wrong, then when the bolt is weighted in a fall, it may be pulled right out of the mountain.

Even the perfect bolt in the perfect setting will not last forever. Since they are outdoors, the bolts and the mountain are constantly exposed to the elements, every day for years at a time. Steel will rust, rock will erode, and general wear and tear will take its toll. Eventually the equipment's strength will degrade so much that it is no longer safe to use.

Whatever the reason, if a bolt fails during use, the climber depending on it will take a longer fall than expected-- possibly all the way to the ground. This is a Bad Thing. Unsafe protection gear is worse than no gear at all, because the danger is seldom obvious to a casual glance. Climbers may tend to just clip the gear and trust their lives to it, unaware that it may give out when needed.

This is where the "re" in rebolting comes in. Enterprising climbers with strong bolting skills investigate sport routes, concentrating mostly on ones that are aging, or that were placed by their less experienced fellows. When they find unsafe gear, the rebolters spend time and money to remove the old crap, and install new, safe, full-strength anchors.

Equipment for a rebolting project can vary widely, depending on the situation. Pulling the old bolts may call for pliers, a crowbar, a funkness device, a "carrot killer", and/or a Y-shaped wedge called a "tuning fork." Enlarging holes and drilling new ones takes a cordless electric hammer drill and spare batteries (or a hand drill, a hammer, and plenty of arm strength). Epoxy is used to patch old holes, and to anchor glue-in bolts. Expansion bolts require a torque wrench. Small brushes and a blow tube clear the dust after drilling. On top of all that, the rebolter needs a full set of climbing gear just to get up where the bolts are, plus of course the new replacement bolts, and he must be able to carry and manage all of it while dangling from a rope 'way up in the air.

Taking all this gear, the rebolter will either ascend a route on top rope or rappel down from above. As he reaches each old bolt he removes it, installs a new replacement, and moves on to the next. This may not sound terribly complicated, but the devil is in the details.

For instance, choosing the placement for the new bolt can be something of a black art. Ideally it would go into the same hole the old bolt came out of, but that's not always possible. The existing hole could be unusable because it is oversized, or fractured, or in the wrong orientation, or has a broken remnant of the old bolt wedged in it, or for various other reasons. A new placement must be found that is close enough, and situated similarly enough, to maintain the same aesthetics and difficulty of the route; yet it must be far enough away not to weaken the rock. Then the old hole must be patched, and camouflaged with rock dust to avoid leaving an ugly scar.

And that's not to mention the difficulty of actually drilling the hole and doing the installation.

Rebolting takes a lot of skill, practice, and dedication. There's no glory in it-- not even the small amount that would come with getting one's name on a brand new route. People put an awful lot of effort into it anyway, even organize themselves into nonprofit groups like the American Safe Climbing Association, to save the lives of strangers they will never meet.


(Just to be clear: this node is absolutely not an instruction manual for doing any of this yourself. If all you know about climbing bolts is what you read on the internet, please do not go out and mess with them, because someone will die.)