I go igloo.

Recently in beautiful Östa national park, I got to try a cold weather alternative to tents and tarps. It's the idiosyncratic Icebox, a device for making catenary curved igloos. 

Usually my Exped Vela I tent is what I turn to whenever I need substantial shelter, it's under a kilo, stable in high winds and usually easy to set up solo. The Icebox is a heavier alternative, coming in at around 2.2 kg, but this is still below what a real 5-season tent can weight, and an igloo does have many benefits over tents and tarps, such as far superior insulation. 

Exped Vela 1, a kilo of reliable shelter. 

This weekend Michi and I will experiment with the Icebox by using it as our only shelter for a back-country ski-tour. However for once I decided to follow the big warning in the manual and tried to build an igloo before relying on it as the only shelter. So here is a brief peek at the first successfully completed igloo from the Icebox. We went to Östa nature reserve to try and build our first igloo there. Östa is a stunningly beautiful area where my good friend and cross-country skiing instructor Sofie has a secluded stuga. Thanks to our recent wonderful wintery weather the snow depth is around 50 cm. 

Ermine tracks.

Here Michi and I tried, with the help of Sofie's stalwart cousin Lisa, to build a 2.75 m (4 person) igloo. Two people are needed to use the Icebox properly, one works on the inside of the igloo, moving the icebox along and packing the snow in, while the other stays on the outside, mixing and shovelling in the snow. With this first attempt every possible mistake that could be made was made, and we retired, drunk with defeat and whiskey, to Sofie's stuga.

The following day Liam (a fellow Irishman from the lovely village of Cork), his viking-blooded brother-from-another-mother Patrick and I tried again, this time with a little more experience, and enough humility to try building a smaller, cosier 2.13 m (1 person) igloo. On this second occasion all the little tricks recommended in the manual were followed to the letter, and the igloo rose triumphantly from the snow. 

Unfortunately no photos of the final rows were taken, which I think is a pity as the sight became quite bizarre at the fifth and sixth row. As the form was removed the blocks of snow seemed to defy gravity as they hung in the air at acute angles. This lack of documentation I will correct for when we build our 3.05 m igloo this weekend. 

Normally I use only an LED torch for light, but for the igloo I thought it would be interesting to try a gas lamp. The Grand Shelters website states that with two candles burning you can raise the internal temperature to just over 0 ˚C with an outside temperature of -26 ˚C. If you've slept at -26 ˚C you may know how much gear is needed to get a good nights rest at that temperature, while at 0 ˚C not much besides a good mat is required. Two candles would put out about 160 W of heat (and 26 lumens), while the Primus lantern puts out 70 W (and 235 lumens) at maximum power. The human body throws off around 100 W at rest, so with two people and the lantern we should be able to keep the igloo toasty. This is all not to mention that the lantern gives a much more pleasantly warm light than with LEDs, as shown below. 

The colour difference in light from the stars and the lantern was the most stark I have ever seen. The following picture is not colour adjusted in any way, the RAW file is as below. Outside was ice-cold blue starlight, inside was warm glowing orange gas-light. This difference in colour was reflected in temperatures, between -10 and -15 ˚C outside and just a little under 0 ˚C inside (which felt completely comfortable after a day working outside). The area we had built the igloo in had only around 40 cm of snow, so when cutting the door it was cut partially through the igloo wall rather than tunnelled down through the floor under the wall. This left a draughty hole, and will be a mistake not made again.  

I was pleasantly surprised when my normally comfort loving fiancé decided to join me in the igloo, she said it was a chance to try something new that she couldn't pass up. Unfortunately, I had only one good quality mat (an Exped downmat 7). She got to lie on that, and there was room also for some parts of my body (ass and feet), but the rest of me got to lie on a 2 cm CCF mat and was unpleasantly chilled. Good gear can make any conditions comfortable, and inappropriate gear can be a pain in the neck. This was something to keep in mind for the igloo, the only place that cold comes from as much as with a tent, is from below. 

In the morning the air holes had gotten these lovely feathered surface hoar frost linings from our moisture-laden breath. 

Immediately after being built, the snow blocks were as soft and yielding as could be expected. The following morning showed much change, as the blocks had now a tough, hard patina of ice on the inside where the block surface melted and then refrozen by the action of the heat from the lantern and our bodies. 

It was rewarding to get the second igloo completed, and to spend a night in it. Not only to see that yes, the Icebox can make a hell of an igloo, but also to learn the ins and outs of how this strange little tool works, and what we can expect this weekend. This trip will be a 4 day romp across the Norrköping archipelago by ski. It was a new moon on Tuesday, so it should be quite the darkest weekend of the season, and as such I hope to get some good long exposures done, so it will primarily be a trip for photography. I also hope to thoroughly document the use of the Icebox in order to make a more detailed review of it here.