When? 3.4-6.4

Where? Berdalsbu (976.1MASL, 200km north of Kristiansand)

Our last ski trip, the mountain safety fieldtrip,took placein an area around the DNT huts Berdalsbu. The trip not only focused on safety aspects like avalanche assessments, but above all covered topics like living in the mountain environment in winterand use this environment as a learning area. On this trip, two mountain guides (Tim and Sindre) accompanied us and gave us lessons concerning these topics.

Day 1: After arriving in Berdalen with our cars and the Troll Aktiv bus, we started skiing with all our gear at 2pm. Our class was divided in two groups. Tim’s group was ahead and kind of leaded us (Sindre’s group) by navigating with map and compass. Although the distance to our destination was only 6km and the way up was really smooth, it took us quite a long time to ski to the hut. Due to bad weather conditions (severe wind) and intensive orienteering in the first group, we had to stop a lot of times and wait in the cold wind. When we finally arrived at the huts around 6pm, we were really happy. Tim gave us an introduction to the “cabin life”, which covered topics like the DNT trust-based payment system, collecting and melting snow, getting firewood and heating the stove and keeping the huts clean and tidy. He also pointed out the importance of active participation and avoiding self-loafing when living together with a group of people in a hut. After this very helpful und necessary introduction, we split in smaller groups in order to get firewood, collect snow and take care of the hut. After heating up the stove and cooking our dishes, we played some board games candlelit.

Day 2:  After a relaxed breakfast, we cleaned the hut, refilled firewood and the snow buckets. The aim was to leave the hut in a better condition than we encountered it. We left the huts and started our ski trip with the purpose of finding a good spot to build our snow caves. Therefore, we stick together in one big group following Tim. To make progress with 26 people can take a lot of time. Thus, we decided to pick a suitable area for digging our snow caves near Berdalsbu. This area was suitable because the slope didn’t entail avalanche risks, the snow was fresh and deep enough to dig in a snow cave. We went back to Berdalsbu and had lunch in the huts. After this energy input, we started digging our snow caves with shovels and saws in small groups of 3 or 4. Aaron, Sam, Laura and me, decided to use the following technique: We dug two doorways 3meters inwards the slope at the distance of 2,5meters. While the person who was digging on the front line by trying to cut out big blocks of snow, the person behind had to shovel them away. In this manner, we rotated once in a while in order to save energy. After about 1 meter we started digging into the sides orthogonally by cutting out snow blocks with the saw on hip height (the height of the sleeping area has to be higher than the entrance, so the cold air only gathers at the floor). Tim gave us very helpful advices by using a special saw-technique. I had expected that the digging would be exhausting, but it definitely outranged my expectations. To regain energy, the person who was shovelling the snow away sometimes rested, drank and ate nutritious food. After about 3,5 hours we managed to connect our two holes from both sides. The main aim was to shovel a dome-shaped ceiling as smooth as possible. This was the most tricky and important step, because only a dome-shaped ceiling has enough pressure to hold the amount of snow on the top. A flat ceiling would sink down over the night. After we flattened our sleeping area, we also dug in a cooking area and little shelves, where we putted candles and other stuff. The next step was to close one doorway entirely. Therefore, we used the big snow blocks we had cut out earlier. To close our main entrance as narrow as possible, was quite challenging, because Laura and me had dug in way to broadly previously. For my next snow cave, I definitely will keep in mind, to only dig the entrance shoulder-width. After 5 hours of digging and sweating, we stood proudly in our big snow hole. Luckily, we could dry our soaking gloves in the huts of Berdalsbu, but it was really nice to have another pair of dry gloves.

We cooked inside the snow cave, enjoyed a nice hot meal and afterwards went for a discovery tour along our little snow cave village. It was really nice to inspect the other snow caves of our classmates. Although we all used the same digging technique, they differed in appearance, room temperature and size.

I started to dig a toilet near our caves and used a big branch of deadwood as a toilet seat. We attached a plastic bag for collecting the toilet paper.

 

 

 

 

 

By candlelight, the four of us snuggled up to another in our sleeping bags and fell asleep happily.

 

 

 

 

Day 3: The night was warm (in the snow cave the temperature stays around 0 degrees) and also making breakfast in our snow cave was quite relaxing compared to our last trips when we slept in tents. We met with the others at 10am and split up in two big groups. While skiing up a quite steep slope, our guide explained differences between types of slopes and how we can identify them on a map. The contour lines of a concave slope are closely spaced at the top of the feature and widely at the bottom, whereas the contour lines of a convex slope show it the other way around. In order to understand how avalanches emerge, this is important to know, because convex slopes tend to be less safe than concave slopes. However, the slope shape is more crucial on smaller slopes than on larger ones. In general, avalanche-prone locations are steep slopes (steeper than 30 degrees). Before going on a ski-tour, it is crucial to check the avalanche forecasters in the destined area. These forecasters show the avalanche risk by using an international avalanche danger scale from low (1) to very high (5). The most accidents happen, when people still go out skiing in a considerable (3) danger level. However, it is important to know how to analyse the conditions on slopes in questionable areas by ourselves.

This can be done by examining the structure and strength of the snow layers in a snow profile. In order to create a snow profile, which determines the stability of snow layers, we were digging a snowpit about 1,5m deep and wide. After that, we first detected the different snow layers by cutting down the pit with a knife. By putting increasing pressure on the top of the section (tabbing with the shovel), we assessed how much force is required to make a layer collapse.

The instability of a layer results from a combination of factors, especially changing weather conditions. For instance, a light and powdery snow can’t support a wet and heavy layer on top. Also new snow normally bonds poorly to ice crusts. These unstable layers can break loose on a steep slope and cause an avalanche.[1] After a lunch break in the DNT hut, we discussed how to use a given area in order to build a varying ski-parcours for children. For this parcours, we created four different stations (1. Slalom, 2. Big ski jump, 3. Organ-pedal run, 4. Bumps run). Afterwards, we were skiing through the parcours by rotating the stations in small groups and grading our best skiers, who then competed against each other in a little competition.

 

 

Day 4: 

After another warm night and packing together all our gear, we had fun while bouncing and destroying our snow caves. Afterwards we split in two skiing groups and set off in different directions. During this tour, we were given the task to build an emergency shelter in 20 minutes. We examined each shelter and discussed the advantages and disadvantages of the different types of shelters. Also, we buried ourselves in snowpits in order to experience the feeling of being covered by a 30cm thick snow layer. Although I formed a breathing hole with my hands I barely couldn’t breathe properly. Only these 30cm of snow pushed heavy on my back and squeezed my lungs together. It was an oppressive feeling. Our last ski trip ended in bright sunshine which was really nice.

[1]GREEN, K. (2006): You’e a what? Avalanche Forecaster. Occupational Outlook Quarterly. Vol.50(4), p.46(2).