Inca rope bridge

Inca rope bridge

Newly reconstructed, the last of its kind
Ancestor	Rope bridge
Related	None
Descendant	Simple suspension bridge
Carries	Pedestrians, livestock
Span range	Short
Movable	No
Design effort	Low
Falsework required	No

Inca rope bridges were simple suspension bridges over canyons and gorges (pongos) to provide access for the Inca Empire. Bridges of this type were suitable for use since the Inca people did not use wheeled transport—traffic was limited to pedestrians and livestock. The bridges were an integral part on the Inca road system and are an example of Inca innovation in engineering. They were frequently used by Chasqui runners delivering messages throughout the Inca Empire.

The Incas used natural fibers found within the local vegetation to build bridges.^{[citation needed]} These fibers were woven together creating a strong enough rope and were reinforced with wood creating a cable floor. Each side was then attached to a pair of stone anchors on each side of the canyon with massive cables of woven grass linking these two pylons together. Adding to this construction, two additional cables acted as guardrails. The cables which supported the foot-path were reinforced with plaited branches. This multi-structure system made these bridges strong enough to even carry the Spaniards while riding horses after they arrived. However, these massive bridges were so heavy that they tended to sag in the middle, and this caused them to sway in strong winds.

Part of the bridge's strength and reliability came from the fact that each cable was replaced every year by local villagers as part of their mita public service or obligation. In some instances,^{[citation needed]} these local peasants had the sole task of maintaining and repairing these bridges so that the Inca highways or road systems could continue to function.

The repair of these bridges was dangerous, to the degree that those performing repairs often met with death. An Inca author praised Spanish masonry bridges being built, as this made for the need to repair the rope bridges moot.

The greatest bridges of this kind resided in the Apurimac Canyon along the main road north from Cuzco.^{[citation needed]}

Renewing the last bridge

The Keshwa Chaca, believed to be the last remaining Inca rope bridge, spans the Apurimac River near Huinchiri, Peru, in the Province of Canas. After a full year of use and exposure to the elements the grass-rope bridge sags and must be replaced for safety. Even though there is a modern bridge nearby, the residents of the region keep the ancient tradition and skills alive by renewing the bridge annually, in June. Several family groups have each prepared a number of grass-ropes to be formed into cables at the site, others have prepared mats for decking, and the reconstruction is a communal effort. In ancient times the effort would have been a form of tax, with participants coerced to perform the rebuilding; nowadays the builders have indicated that effort is performed to honor their ancestors and the Pachamama (Earth Mother). The event has also been supported by video productions for Nova and the BBC and is becoming a minor tourist attraction, with some small tolls charged for tourists to use the road during the festival to walk the newly completed bridge. There is, however, no consistent or guaranteed support for these efforts and tourism remains a relatively minor motivation for the bridge rebuilding^{[citation needed]}.

• 

  The old bridge sags
  (Slide show)
• 

  Notice how much less the new bridge sags
• 

  Builders gather during the renewal
• 

  Preparing side lashings
• 

  Main cable and hand-ropes are in place
• 

  Lashing the hand-ropes to the main side cables.
• 

  Trimmed mat rolls form the bridge deck.
• 

  The new bridge is now complete and in use.
• 

  Bridge in use during the rainy season.

See also

• Simple suspension bridge - the Inca rope bridge built with modern materials and structural refinements
• Suspension bridge - modern suspended-deck type
• The Inca Bridge - rope bridge, secret entrance to Machu Picchu
• The Carrick-a-Rede Rope Bridge - a rope suspension bridge in Northern Ireland

References

Sources consulted

Chmielinski, Piotr (1987). Kayaking the Amazon. National Geographic Magazine, v. 171, n. 4, p. 460-473.

Finch, Ric (2002). Keshwa Chaca: Straw Bridge of the Incas. Ithaca, N.Y.: South American Explorer, n. 69, fall/winter 2002, p. 6-13. – Copies of this issue may still be available for purchase from the South American Explorer.

Gade, D. W. (1972). Bridge types in the central Andes. Annals of the Association of American Geographers, v. 62 (1), p. 94-109. – Showed the bridge at Huinchiri and predicted the art of building it would be lost within another generation, which proved untrue.

Hurtado, Ursula (pub. date unknown). Q'eshwachaka: El Puente Dorado. Credibank (magazine published by Credibank in Peru), p. 22-23. – Describes the documentary film directed by Jorge Carmona.

Malaga Miglio, Patricia, and Gutierrez, Alberto (pub. date unknown). Qishwachaca. Rumbos (magazine published in Peru), p. 30-34.

McIntyre, Loren (1973). The Lost Empire of the Incas. National Geographic Magazine, v. 144, n. 6, p. 729-787.

McIntyre, Loren (1975). The Incredible Incas and Their Timeless Land. Washington D.C.: National Geographic Society, 199 p.

Nova (1995). Secrets of Lost Empires: Inca (1995). PBS TV program, available on video.

Roca Basadre, David, and Coaguila, Jorge, eds. (2001). Cañon delApurimac, La Ruta Sagrada del Dios Hablador. Lima: Empresa Editora ElComercio, 78 p.

Squier, Ephraim George (1877). Peru: Incidents of Travel and Exploration in the Land of the Incas. New York: Harper Bros., 577 p.

Time-Life Books (1992). Incas: Lords of Gold and Glory. Lost civilizations. Alexandria, Va: Time-Life Books.

Von Hagen, Victor (1955). Highway of the Sun. New York: Duell, Sloan and Pearce, 120 p.

Wilder, Thornton (1927). The Bridge of San Luis Rey. Grosset & Dunlap, Pubs., 235 p. – Fictional account of the fall of a rope bridge with loss of life.

Endnotes

External links

• The Last Inca Suspension Bridge: A Photo Album, from Rutahsa Adventures adventure travel
• Inca Roads and Chasquis from Discover-Peru.org
• Inca Bridge to the past from Boston University
• Inca bridges, a Library of Congress lecture
• Slideshow of Keshwa Chaca (Inca rope bridge construction near Huinchiri, Peru) from the website of photographer Doug Klostermann