The boots that helped make mountaineering history
Reporting on SATRA’s contribution to the expedition which 70 years ago led to men standing on top of the world for the first time.
Image © ASKA | iStockphoto.com
After many failed attempts by teams since at least 1921, the peak of Everest – the highest mountain in the world (some 8,848 metres above sea level) which is also known in the region by such names as Sagarmatha, Qomolangma, Chomolungma and Zhumulangma Feng – was finally reached by New Zealander Edmund Hillary and Sherpa Tenzing Norgay on May 29th 1953.
SATRA had been approached by the British Everest Expedition the year before, and accepted the responsibility of designing footwear for the final assault on the very summit of the mountain. The specification for the boots seemed to be straightforward – it called for warm, strong and comfortable footwear that could be fitted with crampons and be simple to both put on and take off. It was apparent, however, that some new and radical ideas would be required to help the climbers cope with altitudes which no climber had ever before experienced.
Up to the time of the British Everest expedition’s approach to SATRA, climbing boots had usually been manufactured from bulky deerskin cocoons which were thigh-length and cumbersome – certainly not the type of footwear needed for the world’s highest mountain climbing challenge. SATRA Director of Research Harry Bradley was given the responsibility of producing the concept for a revolutionary design. His achievement was a very warm, low and lightweight boot which was instrumental in setting the style for many commercial productions during following years.
A team of experienced SATRA footwear experts initially produced four trial pairs of boots. The insoles were made from leather with a lightweight rubberised fabric backing. Rubberised fabric was also used for the linings, and all seams were sealed with latex. The uppers called for a flexible and light leather which exhibited reasonable water repellence. Glacé kid was selected for this essential component, and it was sprayed with latex to provide an added level of protection. Part of the design called for these uppers to be made considerably larger than the linings so that ample amounts of Tropal insulation material – described as ‘an uneven web of kapok fibres’ – could be included (see figure 1).
The decision was made to cement-last the rubberised fabric linings to the backed insole, resulting in a completely moisture-proof inner ‘skin’. This vapour barrier prevented the insulation from becoming wet, which would have reduced the insulation’s effectiveness. It was deemed as acceptable for the climber’s socks to become wet, as long as his feet remained warm.
The leather box toes and counters were moulded to the last during the construction process. An insulating undersole of high-grade felt around 10 mm thick extended a similar amount either side of the insole, and the Tropal insulation was cut so that it touched the felt undersole. The upper was then hand-lasted over it and cemented down, in order to avoid compressing the Tropal.
A reverse welt was hand-sewn through the felt undersole, and a firm but lightweight micro-cellular resin rubber outsole (which measured just over 10 mm thick and with cleats individually cut into each sole) was both cemented and sewn into the welt. Saran socks, which included several layers of Tropal insulation in a sealed envelope, were then inserted into the boot, as were two pairs of duffle socks (a coarse, heavy woollen fabric).
Put to the test
At the outset, the four sample pairs of the SATRA Everest boot were made and sent for assessment in the Swiss Alps during December 1952. Weighing just 1.9kg, they were far lighter than comparable footwear (for example, Swiss climbers in an earlier expedition wore boots which weighed 2.9kg).
Without the benefits of the climatic chambers SATRA has today in its UK headquarters, the cold weather test facilities at the Royal Aircraft Establishment in Farnborough were utilised. The SATRA team’s hard work and knowledge impressed the expedition leaders, who agreed that what SATRA had produced was the best boot for the team. The risk of taking an untried footwear design to the top of Everest was outweighed by the advantages it offered.
The SATRA boot proved so successful that a total of 35 pairs were then requested, which were handmade to fit each member of the expedition team. The sizes required varied tremendously – some of the Sherpa guides needed UK size 6 boots suitable for a very wide fit. By contrast, Hillary’s size 12 feet were narrower than some of the Sherpas’ feet.
The overall production time was very short, with the delivery deadline for the finished boots being just five weeks after the start of the design work. Each pair was delivered complete with removable rubberised stockinettes which were fixed to the outside edge of the sole in order to provide extra protection from wet snow.
After the team’s successful ascent, Expedition Leader Sir John Hunt wrote to Mr Bradley at SATRA, stating that the boots had been worn by all members of the party above an altitude of 6,100 metres and were a great success. Unlike any previous Everest expedition, not one of the British team had suffered from frostbite in their feet. Having been knighted by Queen Elizabeth II for his role in this historical achievement, Sir Edmund Hillary later travelled to Kettering to thank the SATRA team for their sterling efforts.
SATRA is proud of the part it played in helping the expedition team to successfully reach the summit of Mount Everest in 1953, and likewise today considers it a privilege to work with major footwear companies which are involved in the design and production of high-altitude climbing boots. It is said that mountaineers climb mountains ‘because they are there’, so there will always be a need for the best – and safest – footwear to help such men and women achieve their goal in some of the most hostile conditions on Earth.
This article was originally published on page 8 of the May 2023 issue of SATRA Bulletin.