CUCC Expo Rigging Handbook

Bolt belays - placing

Once you've decided where to put your bolt, you have to actually physically place and set it. The methods used differ substantially depending on whether you are using hand bolts (spits) or Hilti HKDS's.

Before you actually start drilling, it is wise to flatten the surface of the rock around the bolt site. This allows the hanger to lie flat against the rock. Different types of hanger have different footprints; bollards have almost no footprint at all, rings and bends somewhat more, and twists a great deal. Remember, of course, that the next person who rigs the pitch may well use a different type of hanger from the one you happen to have handy, and that the club only has about ten bollards left! When dressing the rock, use the pointed end of the hammer and tap gently, so as not to crack the rock below the surface.

Hand spits

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Bolting by Hand

Old-style hand-drilled spits are self-drilling; the spit sleeve functions both as a drill bit and as an anchor. Screw it firmly onto the driver and tap it gently against the surface of the rock, turning it around slightly between each tap and removing it to blow dust away every half dozen blows or so. (You should also tap the spit itself gently to free dust compacted into it). Once the hole is established you can begin to hit a bit harder, but don't overdo it; the idea is to powder the rock at the point of the spit without setting up cracks through the rest of the rock which will weaken it.

Watch out for the spit cratering; this is when flakes of rock crack away around the rim of the hole. A severely cratered spit is greatly weakened as the end of the sleeve is not supported by the rock. With some types of hanger (bollards and Clowns) it is possible to drive the spit in a bit further into the bottom of the crater, particularly if the rope is thin, but this renders it almost impossible to use other types of hanger with that spit.

There is normally a line around the driver stem around 3mm above the thread; keep drilling until this point is reached. (This typically takes around 15-20 minutes of drilling). Now grab yourself a cone, put it in the end of the spit, and hammer it back into the hole. You can normally detect when it is fully set by a change in the tone of the sound when you hit it; it should rise gradually to a high ring. If the hole is the right depth this will coincide with the spit being flush with the surface. Now you can remove the driver and screw in a hanger, and Bob's your uncle.

Peter and Phil's photo guide to placing a spit

Decide where you want your bolt to go.

Before you start drilling, "dress" the rock; that is, hammer away the flaky top surface of the rock and flatten out a small area around where your spit is to go.

Hold the spit driver perpendicular to the rock and start hitting it, gently at first, while rotating it clockwise in between taps.

Make sure the driver is perpendicular to the rock surface.

After every few taps, blow the dust out of the hole.

It also helps to give the driver a tap to remove dust caked up on the end.

When the hole is as deep as the line around the driver shaft (about 3mm beyond the rim of the spit itself), the spit can be set. Take a cone, and fit it into the end of the driver,

like so.

Now hammer it in (without turning it, which would rapidly become impossible) until the spit is flush with the surface.

Finally, squirt a bit of grease into the spit to keep it from corroding. Notice that this spit is rather deep in, and would probably be rather hard to use for a rigging bolt; more dressing would be needed as well. This bolt was actually for the tag on cave 2005-07, and tag bolts clearly needn't be all that strong.

Finished spit.

Power-drills and Hilti anchors

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Using the Drill

Since the first cordless hammer drills made an appearance on Expo 1990 thanks to sponsorship from Bosch, drills have been enthusiastically adopted as the best solution for large-scale bolting tasks; some of the fun and games of recent years, like the 21-bolt traverse over Gaffered to the Walls in 2003, would be unthinkable with hand bolts. However, drills are not suited to use with ordinary spits, as the setting process depends critically on the bottom of the hole being flat. It is possible to drill a hole part-way with a power drill and finish it off by hand, but this is tedious.

Hence we have found it easier to use Hilti anchors, which are specifically designed for use in drilled holes.

before setting - 1k png
Hilti HDK spits before and after setting.
after setting - 1k png

There are two versions of these bolts, the HKD and the HKDS. The latter are easier to use, as they have a "shoulder" around the top of the bolt which sits against the rock, meaning that the depth of the hole is not important.

To place a HKDS, drill the hole in the obvious manner until it is deep enough for the bolt to sit in without touching the bottom. If in doubt, drill it deep! When the hole is deep enough, grab a setting tool and start bashing it.

Start with very gentle taps. The reason for this is so the shoulder can hold the bolt in position until it begins to grip the sides of the hole; if you start by smashing it with all your might, the shoulder will bend and the bolt will disappear, useless, into the depths of the hole. Once it has some grip you can start hitting a bit harder.

It is very important to hit the Hilti setting tools exactly square, as they are made of very hard steel which is rather brittle and hence it is easy to shear the end off. When the bolt is fully set, you should be able to see marks on the shoulder of the spit from the four little teeth on the collar of the driver; don't worry if you can't see all four setting marks, but aim for two at least - one can easily be a consequence of leaning the driver over too far to one side.

Sometimes, in particularly hard rock, it can be impossible to get the setting marks. Use your judgement; if you're not making any progress despite sustained hammering, it's probably OK to stop!