The Swiss mountaineering world is marking the golden jubilee of the 1956 Swiss Mount Everest-Lhotse expedition with a special exhibition in Bern.
The Swiss team achieved the first ascent of the Lhotse peak and the second of Everest.
The 11-man expedition broke three mountaineering records: on May 23 Ernst Schmied and Jürg Marmet became the second-ever team and the first Europeans to climb Everest (8,848 metres); one day later Hans Rudolf von Gunten and Dölf Reist were also successful in conquering the world's highest peak.
Just a few days earlier, on May 18, Fritz Luchsinger and Ernst Reiss became the first climbers to scale Lhotse (8,501 metres).
The mountaineers were welcomed home as heroes when they stepped off the plane in Zurich on July 8, 1956 and their achievements made the headlines worldwide.
Mountains of equipment
The Swiss Alpine Museum exhibition features a wealth of photographs and materials from the 1956 expedition taken from the museum's archives and lent by the mountaineers themselves.
The Swiss Everest/Lhotse expedition, which was organised by the Swiss Foundation for Alpine Research, was extremely well prepared.
Over ten tons of expedition materials were put together meticulously and all the equipment was carefully tested - including in a butcher's cold storage room.
The participants also drew important lessons from earlier successful Himalaya expeditions. The foundation describes how the team's detailed preparations and camaraderie were key factors behind the successful ascents.
Mountaineering and science
The long, hard climb began on March 3 from the Nepalese border town of Jaynagar, where the team had arrived by train from Bombay.
In several of the photos we can see locals helping the Swiss to load the equipment onto 22 oxcarts. A total of 350 porters were hired to carry packs weighing 25kg on a 20-day trek from Chisapani to the monastery settlement of Thyangboche (3,860 metres).
The teams set up base camp, with its own weather station, on the rocky Khumbu glacier (5,450 metres) on April 7.
The expedition had two main objectives: mountaineering success and scientific exploration. Fritz Müller (glaciologist), Jürg Marmet (chemist and oxygen specialist), Hans Grimm (dentist) and Eduard Leuthold (doctor) carried out glaciological and meterological research in the Khumbu glacier region and studied the effects of physical exertion at altitude.
After setting up base camp, the climbers used metal ladders to cross the crevasses on the Khumbu glacier. From here they enjoyed a spectacular view of Lhotse: below a sea of ice blocks and above a dark, imposing cliff.
Oxygen tanks were necessary from 7,000 metres upwards. At the top of Everest air contains only one quarter of the oxygen normally found at sea level.
The success of the expedition was largely down to new, improved and lighter high-altitude oxygen masks and tanks, as well as the good weather conditions.
Among the other photographs on display, Ernst Reiss's courageous, angular face stares out from his thick fur cap on the top of Lhotse. Outside it is 30 degrees below zero.
In another, Fritz Luchsinger can be seen on the summit wearing a duck-down jacket stiff with the cold, which is likely to have slowed him down. On the right, the flags of Nepal and Switzerland, attached to an ice pick, flap in the wind.
Before the first ascent, Luchsinger had been sick for just over one month with acute appendicitis, lying on a makeshift hospital bed in the Thyangboche monastery.
The Swiss expedition marked the dawn of a new era: the Swiss team's mountaineering achievements became a media and marketing event.
The shoe manufacturer Bally took out one-page advertisements for their new reindeer-fur "On the top of the world" boots.
Another sponsor, Wander in Bern, made the malted Ovomaltine products taken on the journey by the mountaineers. The company created an Ovomaltine photo service with images from the expedition.
swissinfo, Urs Maurer
Eleven climbers took part in the 1956 Everest/Lhotse expedition.
Lhotse – the fourth highest mountain in the world – was first scaled on May 18, 1956.
The teams reached the summit of Everest on May 14 and 23, 1956.
The Swiss teams were the second and third to ever scale the world's highest mountain.
The Swiss Alpine Club and the Alpine Museum in Bern are celebrating the 50th anniversary of the Swiss Everest/Lhotse expedition with a special exhibition.
Photographs and original objects from the 1956 expedition will be on display at the Swiss Alpine Museum until August 13.
The Swiss Alpine Club wishes to remind people about the tradition and significance of Swiss mountaineering expeditions.
The exhibition has been organised in parallel with a commemorative Lhotse expedition.