Nepalese Porters May Be World's Most Efficient Haulers
http://news.nationalgeographic.com/news/2005/06/ 0616_050616_nepalporter.html
Ben Harder
for National Geographic News
June 16, 2005
[...]
"Often, you see husband-and-wife trekking teams," Heglund said. Porters stock up on goods in the Kathmandu Valley and carry their loads from dawn to dusk over the course of a week or more to reach Namche, which sits at 11,500 feet (3,500 meters). En route, the porters traverse more than 60 miles (100 kilometers) along rugged footpaths. [...] After the porters sell their goods in Namche, they race home unencumbered for more cargo.
"They literally run down the mountain," Heglund said. "They can get home in about two days."
[...]
A porter's gear is simple but effective: The load goes into an oversized basket, or doko, which rests against the back. A strap runs underneath the doko and over the crown of the head, which bears most of the weight. Each porter also carries a T-shaped walking stick called a tokma.
When on the move, porters sometimes pause more than they walk. "On a steep incline," Heglund said, "they'll walk for as little as 15 seconds and rest for 45." At each stop, they use their tokma to support their load, which allows a standing rest.
[...]
For technical details see
Energetics of Load Carrying in Nepalese Porters
Guillaume J. Bastien, Bènèdicte Schepens, Patrick A. Willems, Norman C. Heglund
Science 17 June 2005:
Vol. 308. no. 5729, p. 1755 (http://www.sciencemag.org/cgi/content/full/308/5729/1755)
"[...] The town of Namche (at an altitude of 3500 m) near Mount Everest hosts a weekly bazaar. Porters (Fig. 1A), predominantly ethnic Rai, Sherpa, or Tamang, typically take 7 to 9 days to travel to Namche from the Kathmandu valley. The route, no more than a dirt footpath, covers a horizontal distance of 100 km, with total ascents (river crossings to mountain passes) of 8000 m and total descents of 6300 m.
One day before the bazaar, we counted 545 male and 97 female porters (and 32 yaks) en route to Namche; others passed by earlier and later in the darkness. We weighed randomly selected porters and their loads (4). The men carried loads of 93 ± 36% of their Mb [Mb = their body weight - ed.] (mean ± SD, n = 96 male porters), whereas the women carried 66 ± 21% of their Mb (n = 17 female porters). The youngest porter was 11 years old, and the oldest 68; the greatest load measured was 183% of Mb, and 20% of the men carried >125% of their Mb. More than 30 tons of material were ported to Namche that day.
[...]
The load versus speed versus energy-cost trade-off chosen by these porters is to walk slowly for many hours each day, take frequent rests, and carry the greatest loads possible. We observed, for example, a group of heavily loaded porters making slow headway up a steep ascent out of a river gorge. Following whistled commands from their leader, they would take up their loads and labor uphill for no more than 15 s at a time, followed by a 45-s period of rest. Incredibly, this group of barefoot porters was headed for Tibet, across the Nangpa glacier (altitude 5716 m), about another week's travel beyond Namche.
So how do they do it? They might reduce the muscular work required to carry a load or increase their overall efficiency. The actual mechanism is unknown at this time."
Please note that the above details were correct on the day this post was published. To suggest an update, please email the site's editor at tmciolek@ciolek.com
Ben Harder
for National Geographic News
June 16, 2005
[...]
"Often, you see husband-and-wife trekking teams," Heglund said. Porters stock up on goods in the Kathmandu Valley and carry their loads from dawn to dusk over the course of a week or more to reach Namche, which sits at 11,500 feet (3,500 meters). En route, the porters traverse more than 60 miles (100 kilometers) along rugged footpaths. [...] After the porters sell their goods in Namche, they race home unencumbered for more cargo.
"They literally run down the mountain," Heglund said. "They can get home in about two days."
[...]
A porter's gear is simple but effective: The load goes into an oversized basket, or doko, which rests against the back. A strap runs underneath the doko and over the crown of the head, which bears most of the weight. Each porter also carries a T-shaped walking stick called a tokma.
When on the move, porters sometimes pause more than they walk. "On a steep incline," Heglund said, "they'll walk for as little as 15 seconds and rest for 45." At each stop, they use their tokma to support their load, which allows a standing rest.
[...]
For technical details see
Energetics of Load Carrying in Nepalese Porters
Guillaume J. Bastien, Bènèdicte Schepens, Patrick A. Willems, Norman C. Heglund
Science 17 June 2005:
Vol. 308. no. 5729, p. 1755 (http://www.sciencemag.org/cgi/content/full/308/5729/1755)
"[...] The town of Namche (at an altitude of 3500 m) near Mount Everest hosts a weekly bazaar. Porters (Fig. 1A), predominantly ethnic Rai, Sherpa, or Tamang, typically take 7 to 9 days to travel to Namche from the Kathmandu valley. The route, no more than a dirt footpath, covers a horizontal distance of 100 km, with total ascents (river crossings to mountain passes) of 8000 m and total descents of 6300 m.
One day before the bazaar, we counted 545 male and 97 female porters (and 32 yaks) en route to Namche; others passed by earlier and later in the darkness. We weighed randomly selected porters and their loads (4). The men carried loads of 93 ± 36% of their Mb [Mb = their body weight - ed.] (mean ± SD, n = 96 male porters), whereas the women carried 66 ± 21% of their Mb (n = 17 female porters). The youngest porter was 11 years old, and the oldest 68; the greatest load measured was 183% of Mb, and 20% of the men carried >125% of their Mb. More than 30 tons of material were ported to Namche that day.
[...]
The load versus speed versus energy-cost trade-off chosen by these porters is to walk slowly for many hours each day, take frequent rests, and carry the greatest loads possible. We observed, for example, a group of heavily loaded porters making slow headway up a steep ascent out of a river gorge. Following whistled commands from their leader, they would take up their loads and labor uphill for no more than 15 s at a time, followed by a 45-s period of rest. Incredibly, this group of barefoot porters was headed for Tibet, across the Nangpa glacier (altitude 5716 m), about another week's travel beyond Namche.
So how do they do it? They might reduce the muscular work required to carry a load or increase their overall efficiency. The actual mechanism is unknown at this time."
Please note that the above details were correct on the day this post was published. To suggest an update, please email the site's editor at tmciolek@ciolek.com
posted by tmciolek at 1:33 PM
<< Home