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< title > CUCC Expo Rigging Handbook: Placing bolts< / title >
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< h2 id = "tophead" > CUCC Expo Rigging Handbook< / h2 >
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< h1 > Bolt belays - placing< / h1 >
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< p > 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.< / p >
< p > 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.< / p >
< h2 > Hand spits< / h2 >
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< div class = "onleft" style = "clear: left" > < a
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href="../../1623/161/l/boltin.htm">< img alt = "(36k image)"
src="../../1623/161/t/boltin.jpg" width="113" height="152" />< / a > < p
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class="caption">Bolting by Hand< / p > < / div >
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< p > 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.< / p >
< p > Watch out for the spit < i > cratering< / i > ; 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.< / p >
< p > 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.< / p >
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< h3 > Peter and Phil's photo guide to placing a spit< / h3 >
< img src = "hand_bolting_guide/img_2989.jpg" / > < p > Decide where you want your bolt to go.< / p >
< img src = "hand_bolting_guide/img_2990.jpg" / > < p > 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.< / p >
< img src = "hand_bolting_guide/img_2991.jpg" / > < p > Hold the spit driver perpendicular to the rock and start hitting it, gently at first, while rotating it clockwise in between taps.< / p >
< img src = "hand_bolting_guide/img_2993.jpg" / > < p > Make sure the driver is perpendicular to the rock surface.< / p >
< img src = "hand_bolting_guide/img_2995.jpg" / > < p > After every few taps, blow the dust out of the hole.< / p >
< img src = "hand_bolting_guide/img_3001.jpg" / > < p > It also helps to give the driver a tap to remove dust caked up on the end.< / p >
< img src = "hand_bolting_guide/img_3002.jpg" / > < p > 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,< / p >
< img src = "hand_bolting_guide/img_3003.jpg" / > < p > like so.< / p >
< img src = "hand_bolting_guide/img_3005.jpg" / > < p > Now hammer it in (without turning it, which would rapidly become impossible) until the spit is flush with the surface.< / p >
< img src = "hand_bolting_guide/img_3006.jpg" / > < p > 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.< / p >
< img src = "hand_bolting_guide/img_3007.jpg" / > < p > Finished spit.< / p >
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< h2 > Power-drills and Hilti anchors< / h2 >
< div class = "onleft" > < a href = "../l/bosch.htm" > < img
alt="(73k image)" src="../t/bosch.jpg" width="200" height="200" />< / a > < p
class="caption">Using the Drill< / p > < / div >
< p > 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.< / p >
< p > Hence we have found it easier to use Hilti anchors, which are specifically
designed for use in drilled holes.< / p >
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< div style = "text-align: center" >
< a href = "../../years/1990/hilti1-300.png" > < img
alt="before setting - 1k png" width="530" height="90" style="margin: 10pt"
src="../../years/1990/hilti1-100.png" />< / a > < br / >
< b > Hilti HDK spits before and after setting.< / b > < br / >
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< a href = "../../years/1990/hilti2-300.png" > < img alt = "after setting - 1k png"
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width="220" height="94"
src="../../years/1990/hilti2-100.png" style="margin: 10pt" />< / a > < / div >
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< p > 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.< / p >
< p > 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.< / p >
< p > 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.< / p >
< p > 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.< / p >
< p > 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!< / p >
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< hr / >
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< ul id = "links" >
< li > < a href = "../index.htm" > Expedition Handbook< / a > - Contents
< ul >
< li > < a href = "index.htm" > Rigging Guide< / a >
< ul >
< li > < a href = "intro.htm" > Introduction< / a > < / li >
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< li > < a href = "boltplace.html" > Choosing bolt locations< / a > < / li >
< li > The mechanics of placing a bolt< / li >
< li > < a href = "exporig.html" > Expo-specific rigging tricks< / a > < / li >
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< / ul > < / li >
< li > < a href = "../look4.htm" > Prospecting guide< / a > < / li >
< li > < a href = "../survey/index.htm" > Surveying guide< / a > < / li >
< li > < a href = "../rescue.htm" > Rescue guide< / a > < / li >
< li > < a href = "../photo.htm" > Photography guide< / a > < / li >
< / ul > < / li >
< li > < a href = "../../infodx.htm" > Index to info/topics pages< / a > < / li >
< li > < a href = "../../indxal.htm" > Full Index to area 1623< / a >
< ul >
< li > < a href = "../../areas.htm" > Area/subarea descriptions< / a > < / li >
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< li > < a href = "../../index.htm" > Back to Expedition Intro page< / a > < / li >
< li > < a href = "../../../index.htm" > Back to CUCC Home page< / a > < / li >
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