inka-road

August 04, 2017

Q’eswachaka, the Last Inka Suspension Bridge

By Allie Plata

Qeswachaka Bridge by Doug McMains
The Q'eswachaka Bridge has been rebuilt continuously since the time of the Inkas. Photo: National Museum of the American Indian, Smithsonian

The importance of the Q’eswachaka Bridge, which crosses the Apurimac River in Canas Province, Peru, is extensive. To understand the impact this bridge has had on the Inka Road and the communities it connects today, it helps first to understand the history behind the bridge.

As the Great Inka Road, or Qhapaq Ñan in Quechua, was constructed, many logistical problems arose. Spanning nearly 25,000 miles, the Inka Road network runs through many different terrains, including the Andes Mountains. To solve the problem presented by steep canyons and gorges, the Inka  pioneered suspension bridges that would allow soldiers, messengers, and officials to safely cross and further expand their civilization's reign. These suspension bridges, which connected regions that had previously been isolated from one another, were essential to the organization and administration of the state and played a crucial role in the social history of the region. After the fall of the Inka Empire, the bridges survived for centuries and continued to serve as vital links in the Andean road system until the 20th century.

Chroniclers claim that the Inka used suspension bridges to extend their rule into new regions as early as the 13th century, when the Inka Mayta Capac conquered lands west of Cusco, and spanning into the 16th century. The Inka military use of the bridges can be divided into two sections: the control of lands and peoples already within the empire and the subjugation of new peoples. Even before the Spanish arrived in the empire, it was a common practice in warfare to cut bridges down or to burn them. The goals were both offensive—to isolate opposing warriors—and defensive—to stop invaders or prevent thoughts of retreat among one’s own army. Once a bridge was destroyed it took weeks to rebuild it. Bridges contributed to the downfall of the empire as well, by allowing the Spanish to cross into Inka territory, although bridges were also burned to slow the Spanish from reaching Cusco.

Pulling the cables taut
The main cables are stretched across the river before the old bridge is cut down. Men from neighboring communities strain to pull the new cables taut.

Inka bridges have three common design characteristics: braided cables of natural fiber form the floor and handrails, stone abutments anchor the cables on either side of the bridge, and vertical ties run between the main cables and handrails. If you look at modern bridges and compare them to the structure of the Q’eswachaka, the Inka bridge differs in that the main cables used to create the bridges not only support them, but also serve as the walkway.

Weaving the bridge 1
Weaving the bridge 2
One team of master bridge-builders begins weaving from the right bank of the river while the other weaves from the left. 

The location of the Q’eswachaka Bridge—the only remaining suspension bridge of its kind—has remained the same since the reign of the Inka. The 500-year-old tradition of construction is maintained by members of four Quechua communities—Huinchiri, Chaupibanda, Choccayhua, and Ccollana Quehue—who rebuild the bridge each year. People from the communities harvest a local grass and prepare it to be woven into cables. All of the cables begin with small cords formed by twisting together the harvested grass. The small cords are then twisted together to form a larger rope, and these larger ropes are braided to create the main cables used to support the bridge.

The communities work together to pull the ropes and stretch them out. Builders leave the old bridge in place until they have hauled the new cables across the Apurimac Gorge, then cut it down and let it fall into the river. Once the main cables that will support the new  bridge and serve as its floor are taut, and the cables that will serve as handrails as well, master bridge-builders work from each end of the bridge to weave its sides. Sticks added every few feet help keep the bridge from twisting. When the master builders meet at the center of the span, all the remains is to lay matting over the bridge's floor. 

The finished bridge
The builders meet in the center of the bridge. Assistants will lay matting over the cables of the floor. Then, everyone celebrates!

The bridge-builders are so skilled, and their collaboration is so well coordinated, that it takes only three days for them to rebuild the bridge. Afterward the local communities come together for a celebration. The bridge connects the communities literally and figuratively. Rebuilding it is a tradition that has been carried on for hundreds of years and a joyous experience for people to be a part of. The Q’eswachaka Bridge acts as a link between the past and the future, and it serves as a great example of the innovation and engineering abilities of the magnificent Inka Empire.

You can see a replica of a section of the bridge, woven by the communities, in the exhibition The Great Inka Road: Engineering an Empire—on view at the museum in Washington, D.C., through June 1, 2020. Or visit the exhibition online in English or Spanish.

Allie Plata (Comanche Nation of Oklahoma) is a student at the University of Kentucky (class of 2018) studying Integrated Strategic Communication and a DJ for the campus radio station WRFL.

Photographs, unless otherwise credited are from the video Weaving the Bridge at Q'eswachaka, produced by Noonday Films for the National Museum of the American Indian. 

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June 23, 2017

Bayonne Bridge Steel Rope, Making History in Lower Manhattan

By Neal Buccino, special to Portfolio, photographs by the Port Authority’s Mike Dombrowski

Bayonne Bridge cable imagiNATIONS
The museum’s exhibition designer Gerard Breen showing the Port Authority’s Roger Prince a model of the imagiNATIONS Activity Center, where the steel suspender rope will be displayed.

Six centuries ago, engineers in the Inka Empire designed cable bridges long enough to span Peru’s mountain gorges and durable enough to withstand earthquakes.

They wove these bridges out of grass and made them remarkably strong, using principles of physics that today support modern-day marvels such as the George Washington Bridge and Bayonne Bridge.

Next year, the Smithsonian’s National Museum of the American Indian in New York—located in the historic Alexander Hamilton U.S. Custom House in Lower Manhattan—will help students learn about these technological achievements, with a little help from the Port Authority. The agency recently donated to the museum a five-foot length of steel suspender rope from the Bayonne Bridge, one of the 152 original steel ropes that held up its 9,800-ton roadway for 85 years.

Made of more than 200 tightly wrapped steel wires, the suspender rope was removed as part of the Port Authority’s Raise the Roadway project, which will permit ultra-large container ships to navigate the Kill van Kull.

Bayonne Bridge cable 1
Roger Prince and the Smithsonian's Kevin Gover with the five-foot section of donated Bayonne Bridge suspender rope.

The cable will live on in the museum’s imagiNATIONS Activity Center, expected to debut next April. There, the steel rope (tensile strength: 950,000 pounds) will be displayed next to a grass rope with a tensile strength of 4,000 pounds, of the kind still used in Peru’s last remaining rope bridge, the Q’eswachaka.

Nearby, suspended from the ceiling, visitors will see a 26-foot section of an actual rope bridge built by the modern-day keepers of the Q’eswachaka Bridge. The 4,500-square-foot imagiNATIONS Activity Center will include interactive exhibits on Native American innovations across fields as varied as engineering and architecture, medicine, and nutrition. 

Bayonne Bridge cable 2 The Bayonne Bridge suspender rope had to be tested for lead and other contaminants before donation. This swab test was performed by Mike Hunt, Office of Safety Health & Environmental Management, Smithsonian.

The exhibit will help visiting students understand how, with flexible strands of any material twisted and braided together, a rope much stronger than its component parts can be created.

“Showcasing a section of Bayonne Bridge steel cable alongside an Inka bridge rope made of ichu grass highlights the continuity in engineering concepts the Inka and their descendants have used for millennia,” said Kevin Gover, director of the National Museum of the American Indian. “Native innovation is everywhere in modern life, and this is one instance where we can directly point to it and provide that a-ha moment.”

“This steel rope carries all the history of the Bayonne Bridge, which in its day was the longest steel arch bridge in the world,” said Roger Prince, the Port Authority’s deputy director of Tunnels, Bridges, and Terminals. “We hope it provides an educational experience for everyone who visits the imagiNATIONS Center.”

Q'eswachaka small

This story originally appeared on Portfolio, the official blog of the Port Authority of New York. Used with permission. The imagiNATIONS Activity Center at the National Museum of the American Indian in New York is scheduled to open in spring 2018.

To learn more about Inka technology, visit the exhibition "The Great Inka Road: Engineering an Empire" online or at the National Museum of the American Indian in Washington, D.C. You can see neighboring communities work together as they do every year to rebuild the rope bridge at Q’eswachaka—including making the grass cables that support it—in the exhibition video here.

Q'eswachaka suspension bridge, 2014. Q'eswachaka, Apurimac River, Canas Province, Cusco, Peru. Photo by NMAI Media Initiatives, Smithsonian

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February 10, 2016

3D Scans of Inka Stonework—Live Online at SI X 3D

Capturing 3D data in Cusco, Peru
Jon Blundell, a 3D digitization specialist at the Smithsonian, capturing 3D data points of the Inka archaeological site at Pisac. Pisac, Peru, 2014. Photo by Samy Chiclla.

If you visit Cusco, Peru, the monumental stonework of the Inka capital will give you a sense of the Inka's imperial ambition. If you come to the National Museum of the American Indian in Washington, D.C., the exhibition The Great Inka Road: Engineering an Empire will show you how the architecture of Cusco reflects the empire's understanding of the Andean environment and principles of construction, as well as political administration. 

But what if you never travel to Peru or Washington? You can visit the exhibition website in English and Spanish or read the companion book of essays. Or, for the first time for this museum, you can experiment with a set of three-dimensional digital models of sites in Cusco, created by the 3D staff of the Smithsonian’s Digitization Program Office

The Cusco models are part of a much larger effort to make the research and collections of the Smithsonian Institution more widely accessible. The institution houses more than 138 million objects, artworks, and scientific specimens. At any given time, less than one percent of these objects are on display. Working with the Smithsonian’s 19 museums, nine research centers, and National Zoo to prioritize material for digitization, the Digital Program Office has set a goal of making ten percent of the collections available online, primarily as two-dimensional digital images. Smithsonian X 3D is targeting far fewer objects. But with web browsers now capable of supporting 3D imagery through webGL, Smithsonian X 3D is breaking new ground.

The Smithsonian X 3D website includes models, as well as a gallery of behind-the-scenes videos about 3D technology in a museum and science setting. Smithsonian X 3D's Inka Road page houses 3D images of stonework from five sites around Cusco, with notes and videos keyed to details of each site and, for Saqsaywaman, a brief tour: 

Waka Pachatusan, a sacred site near Cusco on the road to the province of Antisuyu: 

 


A section of Inka stonework along Hatunrumiyoc Street, including the 12-angled stone that epitomizes Inka dry-stone masonry: 

Screen shot of Hatunrumiyoc


A section of the original wall of the Qorikancha, the religious center of the empire: 

Screen shot of the Qorikancha


A section of wall at Saqsaywaman, the temple of the sun in upper Cusco: 

Screen shot of Saqsaywaman


And an Inka double-jamb doorway, one of three still standing:

Screen shot of the double jamb doorway


To create these models, Smithsonian 3D digitization specialist Jon Blundell joined the museum’s Inka Road project team in Cusco during the summer of 2014. Dr. Ramiro Matos (Quechua), an Andean archaeologist and co-curator of The Great Inka Road, and consulting scholars and other museum specialists on the project team worked with Jon to identify sites around the city for 3D imaging. This was the museum’s first use of 3D scanning technology. “Identifying sites was collaborative,” Jon says. “The team knew that 3D scanning was a tool they wanted to deploy to tell the story. It was interesting to work with them to figure out, What is here that would be compelling as a 3D model, could be captured in the time we have, and has a story behind it?” Once the team had selected the sites, Jon used a combination of laser scanning and photogrammetry—a technique that uses digital cameras and specialized software to create 3D data—to record the surface of each site as billions of 3D data points. 

Jon Blundell on Hatunrumiyoc Street
Jon checking his work on the double-jamb doorway. Cusco, Peru, 2014. Photo by Samy Chiclla.

The Smithsonian X 3D team has digitized other large sites—colonial church burials in Jamestown, Virginia, and a field of fossil whales uncovered at Cerro Ballena, Chile—but working in an urban setting presented different challenges. The City of Cusco provided extraordinary access to the places chosen for scanning, allowing the project team to use the streets at the three in-town sites for long periods of time. The manager of the Saqsaywaman Archaeological Park opened the site at sunrise, long before tourists would arrive, so that Jon and his assistants could collected 3D data, and other members of the project team could film interviews with scholars consulting on the project. And the owner of the modern hotel that uses the Inka double-jamb door as an entranceway graciously let the Smithsonian include that site in the project. 

Back at the Smithsonian, Jon used software to layer the information he had captured in the field and build each 3D model. He began by creating a point cloud. Vince Rossi, a program officer on the 3D staff, describes the data behind the point cloud as essentially a text file with XYZ values for each data point. This durable information will remain useful even as the museum community establishes new standards for archiving data and as software developers write new algorithms to make sense of it. 

The next refinement was to create a black-and-white 3D surface model for each site from its point cloud; laser scanning and photogrammetry geometry data was combined to produce high-resolution geometry using the strengths of each capture method. Next the photogrammetry data was used to projected color onto the geometry. The result is geometrically detailed, accurately colored models. In Cusco, Jon recorded perhaps 40 to 100 gigabytes of raw data for each site. Before posting the models on Smithsonian X 3D, he used techniques developed for digital animators to compress the data and create 3D models that maintain visual fidelity, yet can be downloaded quickly even on mobile devices. 

“That’s what our office does,” Vince explains. “We’re not inventing new technology. We’re leveraging tools that were developed for other industries and developing workflows—the nitty-gritty process of collecting the data and putting together the tool chain that gives us the products the Smithsonian needs. We’re using existing tools in new ways.” 

The Smithsonian X 3D staff compares 3D on the web today to video a handful of years ago. Museums have long had the technology to scan objects in three dimensions at very high resolution. But the ability to deliver 3D content directly to people online, without requiring viewers to download browser plug-ins, is a recent development. People can also download 3D data from the Smithsonian X 3D website, then visualize it in their own software or use it for their own scientific or creative projects, under the Smithsonian terms of use. “That’s more of an experiment,” Vince says. “We’ve already seen people do exciting things—teachers in the classroom creating 3D prints. More and more public libraries have 3D printers.” 

3D-printed Hatunrumiyoc puzzles aside (yes, Jon, Vince, and the third member of the 3D staff, Adam Metallo, have made them), what does 3D imaging bring to Smithsonian research? It provides scientists with new tools to document fieldwork and gives conservators a fast, accurate way to record and compare the condition of objects in the collections. It also enables researchers, and the rest of us, to do things that are impossible to do with actual museum objects. 

To get a glimpse of what that can mean, we have to leave Cusco and look at the 3D model of the Cosmological Buddha. Keith Wilson, a curator at the Freer and Sackler Galleries, the Smithsonian’s museum of Asian art, explains in one of the tours that accompany the model, what distinguished this sculpture are the narrative scenes that completely cover the monk’s robe. On the Smithsonian X 3D site, we can turn the sculpture around to have a 360-degree view or look at a flat map of the carvings, but that’s just the start. 

“Nothing replaces the experience of seeing the sculpture in the gallery at the Freer–Sackler,” Vince says. “But if we go under the hood and turn off the color, that does interesting things, because the color of the stone was interfering with seeing the geometry of the surface. We can further bring out the geometric detail using an ambient occlusion map, which essentially darkens areas of high curvature and lighten areas of low curvature. We can adjust detail live in the browser. All of a sudden we’re better able to get a much better idea of the carving. This is still an accurate representation of the sculpture. It’s just a different way to visualize what’s really there.” 

Cosmic Buddha

This poster, which is available in large format (500 MB file) via the SI X 3D Download webpage (free and open to the public with registration), shows the components of the digital model of the Cosmological Buddha. From left to right: Photo texture, composite occlusion (note how the surface carvings stand out), geometry, normal map, and individual occlusion channels. A print-ready model of the sculpture in low, medium, and high resolution is downloadable from the same site.


“If we back up and look at 3D technology, it’s really nothing more than a form of measurement. We’ve been able to measure things for thousands of years. If we look at the way research at museums is generally conducted, it has included very accurate point-to-point measurement of landmark points on an object or specimen. With a 3D scan, we’re able to replace those few dozen measurements with tens of millions of data points. We’re able to provide whole new tools to researchers and open up a whole new world of investigation. By putting these models online, we’re also opening that world to the public.”


The Great Inka Road: Engineering an Empire is on view at the National Museum of the American Indian in Washington, D.C., through June 1, 2018.

The SI X 3D website includes more information on digitization projects at the Smithsonian, including a gallery of videos that highlight other 3D projects at the Smithsonian and explain the digitization process in detail. 

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July 15, 2015

The Great Inka Road: Engaging visitors in the Inka creation story

One of the best examples of collaboration and synergy across a project I’ve been part of is the “Origin Story of the Inka,” an interactive book produced for the exhibition The Great Inka Road : Engineering an Empire. This simple touch-screen experience allows visitors to page through a digital book and see and hear the Inka creation story brought to life through brilliant images, with audio for every page in English or Spanish. People can read it online by scrolling down in the Ancestors section of the Inka Road website, and a printed version is for sale in the museum shop.

8 capas.eng

According to the Inka myth of origin, Inti, the sun, sent two of his children—Manco Capac and Mama Ocllo—to bring order and civilization to humankind. The pair emerged from Lake Titicaca and headed north to found a city. The city was Cusco. Their path was the first Inka Road.

8 capas
Sample screens, in English and Spanish, from "The Inka Creation Story." Design by Juanita Wrenn/WrennWorks, illustrations by Alejandra Egaña and Paz Puga, Ojitos Producciones.

The museum’s production team worked together to shorten the story into a form that would work well for visitors in the gallery. Illustrations by Alejandra Egaña and Paz Puga—partners in Ojitos Producciones, based in Chile—bring the story to life. Using reference visuals of museum objects and other Inka material culture, they produced images based on Inka iconography and colors. Their delightful compositions fit within the scholarly context of the exhibition and, we hope, will excite the imagination of younger visitors. These illustrations so inspired the exhibition team that we reached out to Alejandra and Paz to create drawings used to visualize aspects of Inka engineering elsewhere in the exhibition.

Juanita Wrenn of WrennWorks designed and programmed a simple, intuitive interactive experience accessible to even early readers. Juanita, who is based in North Carolina, surprised the team by offering to bring an early prototype to the museum, to make sure that what she was producing would work on the gallery touch-screen monitors. Her visit reflects her passion and her dedication to getting all the details right.

IMG_4110

IMG_4107
The interactive book's narrator and her proud mother.

For bilingual audio and sound design we relied on the expertise of the museum’s staff. Veronica Quiguango (Quechua), a collections specialist at the museum’s Cultural Resources Center, offered the talents of her six-year-old daughter. We set up a recording session engineered by NMAI Media Group senior producer Gussie Lehman, and our narrator amazed us by enthusiastically recording the stroy, in English and Spanish, in a single session. She has so much energy we had to take a couple breaks to let her get up and run around the studio a little bit. We felt lucky to capture a wonderfully unique performance that shows off this young person’s fantastic personality. We may eventually add narration in Quechua, since her mother is fluent and she is working on that language as well!

With a wonderful narration in hand, we turned to NMAI Media group producer Mark Christal to add a bit of ambience and sound design. Mark recorded sounds of water, footsteps on a gravel road, and electronic effects combined with music from NMAI Cultural interpreter José Montaño (Qulla [Aymara]) to provide audio details to match the colorful illustrations and the power of the myth.

This project has surpassed our expectations with brilliant contributions from international artists, technicians, staff, and certainly the youngest narrator we have ever worked with. We know that it is an important part of the Inka Road exhibition, helping visitors of all ages access the story of the origin of the Inka Empire and understand the importance of the city of Cusco. Collaborative projects like these are especially exciting, since each contribution complements the others and we end up with something that no single person here could have imagined.

—Dan Davis 

Dan Davis is the manager of the NMAI Media Group.

The Great Inka Road: Engineering an Empire is on view at the National Museum of the American Indian in Washington, D.C., through June 1, 2018.

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I paged through this interactive in both languages several times. I couldn't get enough! I grew up with this legend. Every elementary school student in Peru must learn it. The narration and sound effects were utterly captivating. I just wanted to find your narrator and give her a big hug! The illustrations are simply beautiful, and so appealing! I feel a coloring book coming. You really captured, in a most charmed way, this well loved origin story and have made it even more accessible for generations to come. Buen trabajo!

Amazing post.Very informative...Thanks for sharing.

hi , i read this articles The illustrations are simply beautiful, and so appealing , especially the interactive book you produced for the exhibition its amazing ..

June 24, 2015

Live symposium webcast June 25 & 26—The Great Inka Road: Engineering an Empire

Chinchaysuyu-suspension-bridge-peru
Q’eswachaka suspension bridge, Apurímac River, Canas Province, Cusco, Peru, 2014. Photo by Doug McMains, NMAI 

On June 25 and 26, the National Museum of the American Indian will present a live webcast of the symposium The Great Inka Road: Engineering an Empire. The symposium celebrates the exhibition of the same title, opening at the museum in Washington, D.C., on Friday, June 26.

The Great Inka Road, a sacred network of roads 40,000 kilometers (nearly 25,000 miles) long, connected a confederation of more than 100 Native nations in six modern countries—Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru—and linked them to Cusco, the imperial capital. In 2014, UNESCO recognized this monumental achievement by including the Inka Road on the World Heritage list.

During the symposium, engineers, archaeologists, and other experts and scholars will discuss the political, economic, and religious ideas that enabled the Inka to consolidate power, and the communications, transportation, and agricultural infrastructure that made it possible for them to administer a vast and diverse empire.

The symposium and live webcast will be presented Thursday, June 25, from 1:30 to 5:30 pm, and Friday, June 26, from 9 am to 5:30 pm. Friday's program will feature Spanish-speaking scholars; live webcasts will be offered in Spanish and with simultaneous translation into English.

The webcasts will be archived on the museum's YouTube channel a bit later in the summer.

Symposium program

NMAI live webcasts

#InkaRoad

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