Snow shelters. A vital skill to ensure survival in harsh winter conditions

27 December 2018 digging a shelter on ben nevis

The role of snow shelters for the completion of many famous expeditions bears great historical significance. There is a multitude of famous British mountaineers who have completed groundbreaking ascents as a result of having access to a snow shelter along the way. However, they are crucial for virtually anyone completing a winter expedition. Providing vital protection against wind and snow, and providing appropriate insulation as well. Ultimately, snow shelters are critical for survival and are a skill well worth learning because of this.

Should I build a snow shelter or head back to base for the night?

The decision to either stay put for the night or head back to base can be a difficult one. Spending the night in a snow shelter with little insulation can make for an uncomfortable night. Because of this, if your group is of a reasonable level of fitness and is equipped with suitable gear such as head torches, the best course of action may be to head back. However, if the situation is slightly more severe, for example, a member of your group has injured themselves or is suffering from a health complaint, it may be better to stay where you are.

What is the best location to build a shelter?

Make sure that your shelter is built away from a dangerous location. e.g. an area that could be an avalanche risk.

Consider the direction that the wind is blowing in. For example, you may consider constructing a shelter on a lee slope because it appears to provide sufficient shelter. However, it is possible for transported snow to build up. The same could be said for a shelter built in the direction facing the snowfall. Make sure that no matter what situation you are in, you are well prepared. It is worth pointing out that soft snow can be excavated relatively quickly whereas harder snow can be cut into blocks. However ultimately, it is easier to dig soft snow. Steep slopes often attract a significant accumulation of soft snow. Presenting a perfect opportunity to quickly dig a shelter.

digging a shelter

Bivvy Shelters

If you are new to building emergency shelters, a basic bivvy shelter can be a good starting point. Make sure to dig downwards to a depth of one meter. Then start to dig upwards, leaving an area which can be sat in. You will find that as you dig down, snow will accumulate at the bottom of the trench. However, this can be cleared as you go along. Similarly, you may become covered in snow as you go along. However, the result is definitely worth it.

Shovel up shelter

A shovel up shelter is not a quick fix solution to providing shelter. The amount of time used to construct the shelter can be lengthy. And it is particularly unsuitable for thaw conditions due to the risk of collapse. However, it is relatively easy to build. It also has the added advantage of being able to house multiple people and is a particularly useful form of shelter when combined with an internal ledge and concealed entrance.
The basic process of constructing this shelter is:

  1. Place rucksacks in a mound and shovel snow over them
  2. Once a decent mound exists, begin to bury into it to retrieve the rucksacks
  3. Begin piling snow on the outside. This will eventually solidify
  4. Once the shelter is complete, use either rucksacks or snow blocks to barrier the entrance. Ensure to create that all-important ventilation hole with the tip of an ice axe

If you want to retain as much heat as possible while building the shelter, you might want to consider removing your mid-layer, reserving the spare layer for extra warmth after digging. Nevertheless, the process of digging in its self will generate sufficient heat and keep you warm. Once the shelter has been constructed fully, consider huddling as a group inside. This will generate as much heat and warmth as possible.

Flat ground shelter

In order to build an effective flat ground shelter, you will need to find a layer of snow at least half a meter in depth. However, this type of shelter is relatively easy and quick to construct. There are a couple of tricks for building them even more efficiently. As the shelter is being excavated, pile snow around the sides so that the shelter remains level. Also when hard snow exists on the ground, you may want to consider making a small hole so that the softer snow underneath can be extracted. This reduces the size of the entrance hole that will need to be covered at the end.

  1. Excavate a trench that is slightly larger than all the dimensions of your body
  2. Build blocks around this
  3. Crawl into the trench and make sure you have good access to the blocks
  4. Ensure that the base of the trench is covered to provide insulation against the snow
  5. Use a side foetal position to reduce heat loss. If the shelter is going to house more than one person, make sure it is sufficiently wide enough
  6. Snow can sometimes be too soft to make blocks out of. If so, consider using your bothy bag, while making sure it contains sufficient weight not to blow off
  7. If it is very windy and you wish to use your bag as a cover, but it isn’t heavy enough, create a trench around the excavation so that the fabric of the bag can be secured in snow-filled trenches around the edges
Be sure to practice your new skills

In this post, we have talked about different types of snow shelters that can be constructed in winter conditions. Particularly bivvy, shovel up and flat ground shelters. Although some of the examples we mention are time-consuming, they are easy to construct and suitable for large groups. Be sure to keep safe at all times by keeping your shelter marked on the outside using equipment such as an avalanche probe. Vehicles have the potential to travel over your creation if unmarked. And this can have severe consequences for its inhabitants.

Above all, however, shelters are essential for keeping warm and sheltered. And the only way to get better at building snow shelters is to get out there and practice. As such, have you considered the Scottish Winter Mountaineering course with North East OA? You will learn a range of skills needed for winter climbing, including the all-important emergency snow shelter building techniques that we have mentioned in this article.