Edited by Rachel Duncan 4th Edition ISBN 0-907649-91-2 London ...

76 RGS-IBG Polar Expeditions Manual
• Having controlled the fall you must secure the rope with an ice-screw, deadman, or
snow stake, etc.
• Can you now extricate yourself from the rope system? When you have,
immediately clip a runner onto the rope because where there is one crevasse there is
likely to be another, and do resist the temptation to wander unbelayed for a closer
look. The last person who did that to me was soon sharing the crevasse; fortunately
a shallow one.
• The victim, you and fellow rescuers will soon become cold; be prepared to camp
and warm up.
• Falling down a hole is not as bad as first imagined. Rope-up and practise on a
simple shallow crevasse and you will see that most systems will help arrest
themselves as the rope bites into the crevasse lip.
8.2 River crossings
Crossing rivers and melt streams is a potentially dangerous hazard encountered by many
polar expeditions. Only cross if: (1) the alternative is more dangerous; (2) the crossing can
be adequately safeguarded; and (3) the river is fordable (not swim-able!)
Do not underestimate the strength flow which will be related to speed and depth.
Unless the river is very shallow and slow running you are well advised to use a rope using
the continuous loop method described in Langmuir (1984).
Beware of the rope snagging on submerged rocks and pulling the person crossing
underwater. In such an event rescue will be difficult or even impossible. As a precaution
release your rucksack waistband before crossing so that it can be quickly discarded in an
emergency, e.g. a slip.
See Furse (1997) and Langmuir (1984) for further information.
8.3 Emergency Shelters
8.3.1 Snow camping bivis
Whether or not you have planned to camp on snow, if you venture onto snowfields or
glaciers, you should be prepared to make an emergency ouac (bivi).
Given a reasonable depth of snow you can make a snow shelter. At the very least a
shallow trench overlain with snow blocks, bivi bag, tent or branches, perhaps supported by
skis or an ice axe, will help survival. With more energy you can dig a simple snow cave
although this may take an hour or two. For the committed snow-holer more sophisticated
quarters can be constructed. A crevasse bivi may be the best solution if available.
Read about the structure of snow and the changes that can occur within the snow
layers. Whatever the reason for snow-holing and whatever the final design, always
remember ventilation. Deaths have occurred in snow holes because of carbon monoxide
poisoning. You must prepare an air hole and keep it clear with an ice axe or ski stick.
Igloos are time consuming and for the uninitiated would not count as an emergency shelter.
Nevertheless, they are fun to build, given the right type of snow.