Wednesday, February 8, 2012

Comparison Between Modern and Traditional Inuit Cold Weather Clothing

A few months back I did a post comparing the performance characteristics between modern and early 20th century cold weather clothing. The comparison was along several different factors such as insulation, wind protection and weight, and was performed with respect to the clothing choices of several well known early 20th century explorers. You can see the post here. The result was that the modern clothing outperformed the early 20th century clothing in terms of insulation, and in particular, insulation per unit weight. The early 20th century outfits tested were largely comprised of wool as insulation, with the exception of Amundsen, who used a fur outer layer. His outfit performed the best out of the traditional clothing options.

In one of the comments, a member of this blog pointed me to another study, which looked at a comparison between modern clothing, and traditional Inuit cold weather clothing. I’ve gone through the study, and wanted to share some of the very interesting conclusions with you. For those interested, the study is Comparison of Traditional and Manufactured Cold Weather Ensembles, Clim. Res. Vol. 5: 83-90, 1995.

The study compared three different clothing ensembles. For each of the three choices, the test subjects were wearing the same cotton/polyester underwear and turtle neck shirt, wool socks, and a wool toque. All three ensembles were rated to  -40 degrees C/F.

First Ensamble-1991 Canadian military arctic clothing comprised of an inner and outer hooded parka, pants, wind pants and mittens. The inner and outer pants were made from uncoated nylon canvas outer shell with an inner layer of Polargard (100% polyester) and a layer of Dermoflex (coated fabric) lined with Nomex (a plain-weave natural-colored fabric). The parka (outer layer) and jacket (inner layer) were made from coated fabric (Dermaflex) and lined with Nomex. The parka also had a Polargard (100% polyester) insulation layer. Mitts made of the same layers as in the parka and Amry Mukluks completed this ensemble.

I tried to find a picture of the 1991 Canadian military arctic outfit, but was not able to do so. The closest thing I could find was a picture of soldiers wearing the 2008 Canadian military arctic clothing. Clearly there have been changes since 1991, but I hope it at least gives you an idea of what it would be like to wear it. If someone has a picture of the 1991 version, please let me know.

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Second Ensamble-Expedition ensemble made by Blue Skys Ltd (circa 1995) comprised of an inner and outer hooded parka, pants, wind pants and mittens. Each item consisted of four layers: a nylon lining, open mesh nylon interlining, 6mm layer of Thinsulate, and a Gortex nylon outer layer. Army Mukluks/Skidoo Boots were worn, with composite liners.

I had no success finding any arctic clothing currently made by Blue Skys Ltd. The company still exists, but no longer seems to sell this line of products, nor was I able to find any pictures of any clothing they have made. The picture you see here is from the 1995 Weber/Malakhov unsupported expedition to the North Pole.

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Third Ensamble-Inuit caribou clothing comprised of inner and outer caribou hooded parka, caribou skin outer pants, caribou skin stockings work inside seal skin boots, and caribou skin mittens. The hood was trimmed with dog fur. The inner layer of the parka was worn with the fur facing in, while the outer layer of the parka was worn with the fur facing out.

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The test was performed by having each subject sit in a room for 60 minutes at      -28 degrees C/-18.4 degrees F; 70% relative humidity; 20 km/h wind speed. Temperature measurements were taken at different points on the body throughout the test. The subjective impressions of the test subjects were also collected, but in this post I am more interested in the actual data that was generated, as it is less likely to mislead us.

Before jumping into the results, it should be noted that what was being tested here was the overall performance of each outfit. As a result, there was no attempt to isolate the actual factors contributing to any difference in terms of performance. Keep in mind that the data we see may be a result either of the propertied of the materials being used, or of the design of the clothing. The study makes mention of a few design features that may have created a difference, but no control is being provided in order to test the performance of the materials themselves.

Chest Temperature

In the graph below you can see the chest temperature for each ensemble. This is probably the best area from which to judge the performance of materials rather than design, as there is very little design variation between the clothing choices in this area. Any difference in performance will be either a result of the type of insulation used, or the amount of insulation used.

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As you can see, the Canadian military outfit preserved the chest temperature at a constant level for the duration of the experiment. The Inuit caribou outfit actually increased the chest temperature by about one (1) degree, while the Blue Skys Ltd outfit allowed for a one (1) degree drop in chest temperature. The results clearly show that the caribou clothing provides the best chest insulation, followed by the army clothing (which maintained the exact same chest temperature), while the commercial outfit provided the least insulation, allowing for a drop in chest temperature.

Thigh Temperature

In this next graph, we can see the result in temperature change for the thighs of the test subjects. 

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The Canadian military outfit allowed for a one (1) degree thigh temperature drop over the duration of the experiment. The Inuit caribou clothing maintained the same thigh temperature, while the commercial, Blue Skys Ltd outfit allowed for an almost five (5) degree drop in thigh temperature. Considering that the commercial outfit is made of similar materials to the military outfit, the difference might be an issue of the amount of insulation being used. The Inuit outfit also has a design advantage here as the Parka comes down almost to the knee, providing additional thigh insulation.

Cheek/Face Temperature

In this next graph you can see the cheek/face temperature for each subject.

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Here both the Canadian military and the commercial/Blue Skys Ltd outfits allowed for the similar twelve (12) degree drop in temperature over the duration of the test. The Inuit caribou outfit allowed only for a four (4) degree drop in cheek temperature. The testers postulated that it was the design of the Inuit clothing hood that made the difference, using the fur trim to create a micro climate of the face. 

Finger Temperature

In this next graph you can see the finger temperature for each subject.

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Here the performance of all three outfits seems to be similar, with the Blue Skys Ltd ensemble being slightly warmer. This may be an indication that in the absence of design variation, the different materials might have very similar insulating properties.

Toe Temperature

In the last graph you can see the toe temperature for each subject.

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Here the Canadian military and the Blue Skys Ltd outfits again perform very similarly, allowing for a twelve (12) degree drop during the duration of the test. The Inuit outfit allowed for a five (5) degree drop in temperature.

The study goes on the average the results from each of the above tests, and try to come up with some way of graphing the overall performance of each outfit, but I am not sure what value that has considering the wide variation in performance between different components of each ensemble. As few of us can get our hands on a 1991 Canadian military arctic weather outfit or a 1995 Blue Skys Ltd cold weather outfit, the performance of individual elements might be more significant.

It appears that in terms of the chest and finger insulation, all three outfits had a similar performance. In terms of the thighs, the commercial outfit showed a significant lack of insulation when compared to the military and Inuit outfits, and in term of toe and face protection, both the military and commercial outfits were significantly outperformed by the Inuit clothing.

Few things I was curious about:

As far as I know from modern military clothing, an arctic weather outfit is comprised of multiple layers. I am not sure why they were not used in this case. It seems that all that was used was the base layer and the parka. It makes for good comparison in terms of clothing items, but I’m not sure it correctly reflects the overall military cold weather outfit. If anyone has more information on the 1991 Canadian military arctic clothing components, please let me know. 

It is interesting that so many early 20th century cold weather explorers rejected fur as a clothing option. With the exception of Amundsen, who used it as an outer layer, most explorers stayed away from it as not being worth the effort. This study seems to indicate that they would have all been much better wearing fur rather than wool. Interestingly, Nansen did not use fur on his travels, but he did use fur coats when on the Fram while attempting to reach the North Pole. Perhaps it was an issue of mobility-avoiding furs unless inactivity was expected.

It is a shame that none of the weights were provided for the clothing. Temperature data is good, but it usually has to be placed in the context of weight. After all, insulation is not much good when you can not move in it. This may have had a significant design influence on clothing like the military arctic ensemble, which has to prioritize mobility and combat effectiveness.

The good thing about data is that it speaks for itself. There isn’t much more I can say beyond that. As always, it would have been great if we had more complete data with respect to factors such as weight and ability to move, but it’s great that we at least have some studies that can guide our choices. If any of you are familiar with any other tests on the subject, please let me know, and I would be happy to go through them. 

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