Snow Place Like Home!
- March 4, 2016
- Posted by: Terry O'Connor
- Category: Survival
Todd’s Ten Tips for Efficient & Safe Snow Shelters
University of Colorado School of Medicine, Wilderness & Environmental Medicine Section
1. Bring the right tools – A snow shovel made for backcountry travel is an essential winter safety tool. A snow saw can be helpful for making blocks and an avalanche probe helpful for determining snow depth. Wearing water proof clothing during building will help keep one drier.
2. Location, location, location – Perhaps the most important decision to be made is where to build the shelter. For a snowcave a hillside (25-40 degree slope) is ideal as it allows for easier snow removal and it allows digging upward, ensuring a heat trap. If the ground is flat than a quinzee (see below) or ranger trench may be the best bet.
3. Quinzees, solution to shallow snow – If the snowpack is less than about 5 feet or 1.5 meters in depth, then a quinzee is probably the best bet. A quinzee is constructed by piling snow at least 6 feet high in mound that is about 12 feet or 4 meters across. Compacting the snow with snowshoes is helpful, or, in relatively mild winter temps within 5 or so degrees of freezing, waiting several hours for the snow to consolidate will allow for thinner walls and thus more space. Once the mound is ready to go, simply dig it out like a snow cave.
4. Entrance – The entrance is ideally small (to retain heat) and on the downward side or includes some kind of cold air trap (a step dug down) to retain heat in the “living area.”
5. When time is of the essence – A snow cave on a good 40 degree slope in soft snow can be dug relatively quickly (~1-3 hours). However, if conditions are not good and time is of the essence, then two tricks for quicker construction are: a) Make the entrance bigger and then go back and re-block it to make efficiently small once again; b) For larger groups where the structure will be bigger, make two entrances and then later block one off so there are no cross breezes and heat is more efficiently retained. This is especially effective with quinzees.
6. Ranger Trench, quick shelter on the flats – On flat surfaces a very quick shelter is the ranger trench. A ranger trench is basically just a trench, approximately 8 feet or 2.5 meters long (longer for bigger groups). The key is to make the surface cut only 2 feet or .5 meters wide and then dig down and out to make the base 4-6 feet or 1.5-2 meters wide. In cross-section the trench should look like a trapezoid, with the narrow part at top. The opening at the top is ideally covered by an A-frame of snow blocks but if there isn’t time or good “block snow,” then a tarp, tent/tent fly, or conifer boughs could be used.
7. Roofs – For quinzees and snow caves dome the interior ceiling for strength, to reduce sagging, and to keep any drips running down the sides. Ideally the roof will be at least a foot or .3 meters thick.
8. Interior design – Bring out your inner Martha Stewart by making candle and/or stove niches, shelves for gear, seats, etc. etc. Your designs are only limited by your imagination. A door can be constructed out of a sled, snowshoes, a pack, or a big snow block.
9. Snow shelter living – Make sure you have plenty of insulation between you and the cold snow or ground. That might be a sleeping pad, crazy creek chair, pack, or, in an emergency, confer boughs. If you have a tarp, placing that under you can add a little warmth and dryness, but most importantly it reduces the chances of losing gear into the snow. It will be humid inside so try to avoid using down if possible and keep everything in stuff sacks, packs, or plastic bags.
10. Safety – Depending on snow consistency, snow shelter construction, and how long the shelter has been occupied, a ventilation hole may be important for ensuring fresh air. (A ventilation hole can be made with a ski pole (handle first), ice axe shaft, avalanche probe, or stick.) If cooking inside the shelter, light the stove outside or near the entrance, and a ventilation hole should definitely be made. Always keep a couple of snow shovels in the shelter with you in case the entrance is snowed in or in the very unlikely event of a collapse. In areas where other people may come across your shelter mark the boundaries of your shelter with ski poles, skis, snowshoes, or sticks to prevent someone from “dropping in” on you.
In an emergency, in extremely cold weather or high winds, on steep slopes, or when going ultralight, a snow shelter can be a much more comfortable alternative to an open air bivy or even a tent. Practice making snow shelters before you need one for real and have fun being a little kid once again!