mirror of
https://expo.survex.com/repositories/expoweb/.git/
synced 2024-11-22 15:21:55 +00:00
123 lines
5.2 KiB
HTML
123 lines
5.2 KiB
HTML
<!DOCTYPE html>
|
|
<html>
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf8" />
|
|
<title>Stone bridge bivi rigging guide</title>
|
|
<link rel="stylesheet" type="text/css" href="../css/main2.css" />
|
|
</head>
|
|
<body>
|
|
|
|
<h1>Bivi Rigging Guide</h1>
|
|
|
|
<p>Every year some poor bugger who has probably never done it before it
|
|
gets to rig the tarps and be responsible for any soggy miserable
|
|
nights that might result if it's not done well enough. Starting from
|
|
the bare space it's really quite hard to know where to start if you've
|
|
not done it before, so this doc attempts to provide some advice.</p>
|
|
|
|
<p>Note that this was written after Wookey+Joe's rigging effort in
|
|
2014. It is not necessarily optimum, but did seem to more-or-less
|
|
work. Feel free to improve it over time.</p>
|
|
|
|
<p>There are two essentially-separate jobs:
|
|
<ol>
|
|
<li>the
|
|
<a href="water">water-collecting tarp</a>, and </li>
|
|
<li>the <a href="#main">main tarp</a></li>
|
|
</ol></p>
|
|
|
|
<p>If there is any chance of it raining soon, <strong>start with the <a href="water">water
|
|
tarp</a></strong>, as you <strong>really</strong> don't want to miss collectingt all that water, and
|
|
setting up in the rain is rubbish.</p>
|
|
|
|
<h2>Terminology</h2>
|
|
|
|
<p>I will describe things as if standing at the bottom entrance looking
|
|
up, because that works for all three sections. So the
|
|
<strong>left</strong> wall is the
|
|
gear/stove/animal-hole wall. The 'back' is the top end of the bridge.
|
|
The 'front' is the main entrance.</p>
|
|
|
|
|
|
|
|
|
|
<h2 id="main">Main roof tarp</h2>
|
|
|
|
<p>How not to do it</p>
|
|
<img src="i/bivirignm.jpg" alt="Bivi Rigging Nightmare" width=800>
|
|
<p>Since 2015 we have one really big (15x10m, white) tarp (rather than
|
|
the smaller 10x10 green one, shown in the diagram). This covers the whole
|
|
sleeping area from front to back and is a lot drier. It is set up so
|
|
that essentially the whole bivvy is covered. The tarp is just about
|
|
wide enough to span the width of the bivvy. The instructions below are
|
|
a good guide as to how to set up any tarp, and the large white tarp
|
|
actually has a few instructions written on it. You can largely ignore
|
|
the 'fold' notes, and use your own judgement.</p>
|
|
<img src="i/bivirig.jpg" alt="Drawing of pre-2015 tarp layout" width=800>
|
|
|
|
<p>Start with the big white tarp. The long edge goes from front to
|
|
back of the bivi. The basic position is that it goes all the way to
|
|
the right wall, partly 'underneath', and the left hand edge crosses
|
|
the steps up the middle. The back edge reaches the floor behind the
|
|
top 3-person flat area at the back entrance.</p>
|
|
|
|
<p>So start by opening it out to full width on the wide central
|
|
bed-shelf. and pulling the RH edge close to the wall. Sequencing the
|
|
ropes is a bit tricky, you need the tarp vaguely in place, then
|
|
install the two main ropes to lift it up. Finalise the tarp position
|
|
and tension it.</p>
|
|
|
|
<p>Once the tarp is somewhat spread out, rigging the ends of the two
|
|
main ropes - one across the front and one across the middle (passing
|
|
under the tarp). These are the two that take high loads. The rear
|
|
major rope has no real load - it just keeps things neat. Now tension
|
|
them to lift the tarp up and ensure it is neatly spread. The middle
|
|
rope attaches to the roof bolt just at the LH edge of the tarp. This
|
|
needs someone very tall, or sitting on shoulders, or something devious
|
|
with bivi string to pull it tight.</p>
|
|
|
|
<p>P.S. At the rear entrance, you can rig up some extra tarps to make
|
|
it more comfortable.</p>
|
|
|
|
<p>This is one large tarp covering most of the internal
|
|
roof. There are two main cross-ropes to hold it up, ties at the back
|
|
edge and 'knitting' to reduce sagging in the almost-flat central area.
|
|
The objective is to get it taut enough and square enough that almost
|
|
all the water runs down the top and out the front not collecting in
|
|
'buckets', which then drip. That means that it has to be fitted quite
|
|
'flat'. </p>
|
|
|
|
<p>Ideally the lines that run down from back to front should be so tight that
|
|
no cross-lines are needed. Thene there can be no dripping pockets at all. This requires
|
|
threading lines through maillons in the roof, rather than tying them off,
|
|
then pulling down on the line with all your weight (jammer and a friend useful)
|
|
before tying off at another bolt at about waist level.
|
|
You should not need to put in new bolts, they should all be in place already.
|
|
|
|
<h3>Rear entrance tarps</h3>
|
|
<p>to be written</p>
|
|
<h3>Frot entrance tarps</h3>
|
|
<p>to be written</p>
|
|
|
|
<h2 id="water">Water tarp</h2>
|
|
|
|
<p>Use a long/thin (2x5m) waterproof 'logpile' tarp. It is hung
|
|
between two side longitudinal ropes, with lots of bits of string
|
|
attaching the eyelets to the side ropes. Aim to hang it under the hole
|
|
in the roof, and far enough forward that water off the front falls
|
|
onto the 'water platform' (not into the food boxes).</p>
|
|
|
|
<p>It's easiest to approximately tie the tarp to the side ropes with
|
|
adjustable knots, then put the ropes in place, adjusting as you
|
|
go. The outer line ends up too high to adjust once properly in
|
|
place. Adjust it to catch as much of the water falling through the
|
|
hole as possible, and slope gently, but consistently downwards.</p>
|
|
|
|
<p>In past years we have hung the funnel in the hole. This is a faff
|
|
and misses a lot of water. Just hang it below the end of the tarp where
|
|
it will get nearly all the water and is much easier to hang/adjust/unclog.</p>
|
|
|
|
|
|
</body>
|
|
</html>
|