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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
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<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>CUCC Expo Rigging Handbook: Artificial belays - bolts</title>
<link rel="stylesheet" type="text/css" href="../../css/main2.css" />
<style type="text/css">
ul.spacedout li { padding-top: 1em; }
</style>
</head>
<body>
<h2 id="tophead"> CUCC Expo Rigging Handbook</h2>
<h1>Bolt belays - choosing a location</h1>
<p>Deciding where to put the bolts for a new pitch is something of a black art,
which can be acquired only through much practice and wide experience of SRT in
general. This guide cannot substitute for experience underground.
<!--Particularly as the author has only ever bolted three pitches.
--></p>
<p>Inasmuch as there can be such a thing as a "typical" pitch, the "typical"
rig might be something like this. Start off a traverse line somewhere nice and
far back; often this gives you enough choice of location that you can use a
natural. Approach the pitch-head carefully, gardening as much loose material as
you can before there are cavers or ropes below for it to hit. Look for
somewhere good to place a Y-hang; if the pitch is awkward, this may have to
become a tri-hang - a very typical Expo pitch-head technique is a Y-hang
followed immediately by a deviation, to give full three-dimensional control
over the position of the hang. (Showoffs can achieve the same effect with a
triple bowline, if they know how to tie one.)</p>
<p>Having got the pitch-head bolts in, descend carefully, looking out below you
for any potential rub points, and looking around for good places to rebelay or
deviate. Remember that a deviation to avoid a rub point is only any use if it's
some way above the rub; don't just ab down until it starts rubbing and then
start looking for a rebelay or deviation.</p>
<p>Placing mid-pitch bolts is often a challenging business requiring you to
dangle on miniscule ledges or wedged against the walls while you drill. Don't
overdo it; if it's difficult to put the bolt in, it'll be difficult to rig off
in future. Many seasoned riggers swear by skyhooks as a means of positioning
yourself while you bolt, but don't rely on everyone else who uses the bolt
owning a set! Another trick is to use a borderline natural, which you wouldn't
trust to rig off, to support yourself while you drill.</p>
<p>Some caveats:</p>
<ul class="spacedout">
<li> Watch out for poor rock quality. In most cases the choice of anchor
placements is a compromise between the requirements of the hang and the
necessity of putting your spits into decent rock. Cracks are obviously to be
avoided; mineral veins are also apparently bad, but often there are so many of
these there's no way you can avoid them. Once you've settled on a
likely-looking location, get your hammer out and give the rock a few taps with
the pointy end. It should give a convincing high ringing noise, not a hollow
thud. (The difference in sound is much accentuated by a hammer with a metal
shaft, such as the Petzl bolting hammers, which are expensive but very good;
the club's cheap fibreglass-shafted hammers are rather more difficult in this
respect.)</li>
<li>If your chosen location is in a large block of rock which is well held
together but not well attached to the wall, it can look and sound fine, but
hold a nasty surprise in store. I was once about to start drilling in a
promising-looking location, marred only by a crack in the rock at least 20cm
away from where I wanted to bolt. Some suspicion made me stick the point of my
hammer in the crack and lever on it, at which point a plate of rock about a
metre across and half a metre thick slid off the wall and down the pitch,
taking my proposed spit location with it! Be alert for this sort of thing.</li>
<li>Bear in mind how difficult the rig will be for the user. In most cases, if
it's difficult to rig it'll be difficult to pass and vice versa, but watch out
for subtle gotchas like putting your Y-hangs too low down; this can make the
pitch impossible to get off! Don't force yourself and your companions into
dangerous manouvres like prusiking up one arm of the Y-hang.</li>
<li>When considering how the rope will hang from a particular location, don't
forget to take into account the length of the hanger and maillon. It almost
always needs to be higher up than you expect.</li>
<li>Spits are very much stronger when loaded perpendicular to their axis; so it
is usually best to place spits horizontally into the wall, which is usually the
easiest method anyway. Bear in mind the safe loading angles for the different
types of hanger - only rings, clowns and bollards can take a straight outward
pull. Bends are good for Y-hangs, where the pull is at an angle away from the
wall; twists are best left for straight downward pulls.</li>
</ul>
<hr />
<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>
<li>Choosing bolt locations</li>
<li><a href="boltin.htm">The mechanics of placing a bolt</a></li>
<li><a href="exporig.html">Expo-specific rigging tricks</a></li>
</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>
</ul></li>
<li><a href="../../index.htm">Back to Expedition Intro page</a></li>
<li><a href="../../../index.htm">Back to CUCC Home page</a></li>
</ul>
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<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>CUCC Expo Rigging Handbook: Expo-specific rigging tricks</title>
<link rel="stylesheet" type="text/css" href="../../css/main2.css" />
</head>
<body>
<h2 id="tophead"> CUCC Expo Rigging Handbook</h2>
<h1>Exotic rigging tricks: pendules, tyroleans, ...</h1>
<p>There are many obscure tricks of rigging that are specific to the case of
exploration, and are rarely used in UK-style SRT.</p>
<h4>Pendules</h4>
<p>A pendule is a technique for crossing a void more or less horizontally. It
can only be rigged if you can get to both ends. The essential idea is to
suspend a length of rope loosely across the pitch, anchored securely at both
ends. To pass it, rig your descender on the rope and descend, as you would a
normal pitch. Once the loop of rope below, going back up to the anchor at the
far end, starts to become tight, attach your jammers to it and pull rope
through until they take your weight; now prusik on this side, pausing to let
out the rope through your descender as needed.</p>
<p>There are a number of pendules <a href="../../fixaid.htm">left rigged</a> in
CUCC's caves, to avoid having to repeat death-defying climbs and traverses that
were originally used to reach the far ends.</p>
<p>Practice above ground suggests that pendules work very badly unless
the hole below is reasonably deep, probably at least half as deep as the length
of the pendule; otherwise you end up prusiking against the force of the tension
in the near-side rope to avoid hitting the deck, which is extremely hard
work.</p>
<h4>Tyrolean traverses</h4>
<!-- This needs work. I haven't actually ever done a tyrolean underground, and
I think it shows! -->
<p>A tyrolean is used in much the same places as a pendule - roughly horizontal
traverses across voids - but is much more difficult to rig, and dangerous if
not rigged right. The idea is to have a tensioned line across, which you can
then run a pulley along.</p>
<p>The risk inherent in this is that of a <i>t-hang</i>, where the tension in
the rope for even relatively light loads becomes enormous. To rig a tyrolean
safely, really massive anchors are needed at each end - big naturals with
backups, or multiple spits - with a completely independent backup line rigged
parallel to the main line (but not under tension). A Z-rig or something similar
can be used to tension the rope.</p>
<p>Tyroleans are also important in rescue rigs, where they can be the only safe
way to transport a stretcher across a traverse; this lies out of the scope of
this guide, and is well covered in <i>Life on a line</i> (available online
somewhere; on Exo there should be a copy in the tatty hut.)</p>
<h4>Rope protectors</h4>
<p>Rope protectors have now all but disappeared from sport caving in the UK,
and I think it is fair to consider them an Expo-specific trick; I have never
used a protector except in Austria.</p>
<p>A protector is essentially a sleeve of tough material that wraps around the
rope with Velcro, and can then be clipped into place with a bulldog clip at the
rub point. They are more or less self-explanatory to use - just remove the
tector when you reach it and replace it once you've passed the rub point; I
include them here because it is easy to forget that they exist. As a general
principle, it's probably not a good idea to use them on trade routes, but they
are ideal for the situation where you just want to descend a pitch quickly to
find out if it goes or not (but don't forget to rerig later if it does go
somewhere significant!)</p>
<p>If you don't have a tector handy, it's often possible to improvise using an
empty tackle sack or dangly bag - you may need to hold it in place until your
weight is across it on the rope, which should then keep it secure.</p>
<hr />
<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>
<li><a href="boltplace.html">Choosing bolt locations</a></li>
<li><a href="boltin.htm">The mechanics of placing a bolt</a></li>
<li>Expo-specific rigging tricks</li>
</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>
</ul></li>
<li><a href="../../index.htm">Back to Expedition Intro page</a></li>
<li><a href="../../../index.htm">Back to CUCC Home page</a></li>
</ul>
</body>
</html>