Friday, December 9, 2011

Comparison Between Modern and Early 20th Century Cold Weather Clothing

It is an unfortunate fact that when people set out to prove something they already strongly believe, they knowingly or unknowingly tailor data to reach the desired results. Clearly that is something that each of us has to encounter at some point. Of course, the way to correct for those misconceptions, is to perform well controlled, duplicatable studies, so that the results can be judged by the rest of the scientific community.

Earlier I did a post looking at the clothing choices of some early 20th century cold weather explorers. You can see the post here. In recent years people with agendas of their own have made claims, which in turn have been picked up by other people with their own agendas, and as a result, most scientific data about the clothing that I discussed has been lost amid romanticism, nostalgia and wishful thinking. A clear example is the tests that Graham Hoyland performed in 2006, using George Mallory’s clothing. The “test” concluded that the clothing is very comfortable and warm, along with a number of other overly romanticized musings on the subject, by a person who has the clear goal of establishing that Mallory was in fact the first person to summit Everest. I have seen at least several people who based on Hoyland’s statements (with no further independent research) have concluded that the 1924 clothing is superior to modern cold weather clothing. 

So, I decided to do some research and see if I can find any actual scientific studies, which produced data on the subject rather than subjective evaluations. Interestingly, I found that such tests have actually been performed on both George Mallory’s clothing as well as that of Robert Falcon Scott and Roald Amundsen: Benchmarking Functionality of Historical Cold Weather Clothing: Robert F. Scott, Roald Amundsen, George Mallory, by George Havenith, Department of Ergonomics (Human Sciences) Loughborough University. The photographs used in this post are from the study.    

The below picture shows a side by side of Scott’s, Amundsen’s and a modern cold weather suit, used in the test.

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Here the same clothing can be seen on the thermal manikins.

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Here you can see Mallory’s clothing as used in the test.

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The study was performed at Loughborough University and the clothing of Mallory, Scott and Amundsen was compared along several categories and factors to modern cold weather clothing, containing fleece and down insulation. Of the vintage clothing, the warmest possible combination of items was used for the test, with the Amundsen clothing being tested with both the reindeer and seal skin outer layer in the alternative.

Each clothing arrangement was placed on a thermal manikin is a controlled temperature environment. The insulation values were measured in units of clo (1clo=0.155 m2C/W).

The first test looked at insulation without the addition of any other factors such as wind. The graph below shows the results.

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The results clearly show that the insulation value of modern clothing is higher than any of the other options. The Amundsen clothing with reindeer shell has the next best insulation, followed by Amundsen’s clothing with the seal skin shell, followed by Scott’s clothing, and in last comes Mallory’s clothing. It has been mentioned by some people that Mallory’s clothing was lighter than modern clothing used on Everest trips. While objectively true, it also provides significantly less insulation.

The second test, or more accurately, calculation, shows the insulation value as compared to the weight of the clothing. In the chart below we can see the insulation value (clo) per kilogram.

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Here we can clearly see that for the weight, the modern clothing significantly outperforms the vintage options. The modern clothing provides more than twice the insulation per kg than Scott’s and Amundsen’s clothing, and 1.65 times better insulation per kg than Mallory’s.

The third test looked at how much insulation is retained when the clothing is exposed to wind. The chart below shows the insulation value as a percentage of the static insulation.  

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The modern clothing again shows to be the best, closely followed by Amundsen’s clothing with the reindeer shell.

A fourth aspect of the clothing was tested in a study by Dorman LE. Havenith, The Effects of Protective Clothing on Energy Consumption During Different Activities, Eur J Appl Physiol. 2009 105(3):463-70.

The study showed that not only weight, but also the bulkiness and layering of clothing contributed to energy consumption. Simply stated, bulky clothing makes it harder for you to move, and makes you use up more energy for the same tasks. The table below shows the increase in metabolic consumption caused by each clothing option looked at above. There is no exact data for Mallory’s clothing, but the study concluded that the layers of silk between the wool would make movement easier, decreasing the metabolic expenditure when compared to that of Scott who used similar wool layering.

Clothing Combination % increase of metabolic rate when sledge pulling % increase of metabolic rate when dog sledding
Scott

24%

n/a

Amundsen

18.5%

10%

Modern Clothing

12.5%

7%

It is again clear that the modern clothing is a lot less cumbersome, and requires less energy expenditure to operate.

The conclusion reached by the above studies is that while Amundsen’s clothing provided better insulation than Scott’s, considering that Scott largely man hauled his sleds to the pole, unlike Amundsen who used dogs, the clothing would have provided adequate insulation. Both Amundsen and Scott would have found their clothing deficient during periods of inactivity, as was in fact noted by Amundsen in his journal. The big problem for Scott would have been the high energy expenditure required by the clothing. 24% increase in energy consumption is significant and would have greatly contributed to the expedition’s unfortunate end. With respect to Mallory, the studies concluded that his clothing would have been adequate down to -30 degrees Celsius. However, if any high wind speeds were encountered (above 40 km/h), or there was any inactivity, the clothing would have been deficient.   

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