Leonardo Bridge Project

In 1502 Leonardo da Vinci did a simple drawing of a graceful bridge with a single span of 720-foot span (approximately 240-meters.) Da Vinci designed the bridge as part of a civil engineering project for Sultan Bajazet II of Constantinople (Istanbul.) The bridge was to span the Golden Horn, an inlet at the mouth of the Bosphorus River in what is now Turkey.
The Bridge was never built.

Leonardo's "Golden Horn" Bridge is a perfect "pressed-bow." Leonardo surmised correctly that the classic keystone arch could be stretched narrow and substantially widened without losing integrity by using a flared foothold, or pier, and the terrain to anchor each end of the span. It was conceived 300 years prior to its engineering principals being generally accepted. It was to be 72 feet-wide (24 meters), 1080-foot total length (360 meters) and 120 feet (40 meters) above the sea level at the highest point of the span.

Norwegian painter and public art creator, Vebjørn Sand, saw the drawing and a model of the bridge in an exhibition on da Vinci's architectural & engineering designs in 1996. The power of the simple design overwhelmed him. He conceived of a project to bring its eternal beauty to life. The Norwegian Leonardo Bridge Project makes history as the first of Leonardo's civil engineering designs to be constructed for public use.

Vebjørn Sand took the project to the Norwegian Public Roads Administration. Though hardly a visionary organization, when Sand presented the project the reaction was unanimous. "Everyone on the project knew we would be making something more than another boring bridge," Sand says of his meetings with government officials, "We would be making history."

On the Project, Vebjørn Sand successfully collaborated with a professional team of engineers and architects to test the build-ability of the design. Numerous sites were considered all over Norway until the right one was found in the township of Ås spanning E-18, the highway linking Oslo and Stockholm. Fundraising for the project also became a major responsibility for Sand. The next five years required the ability to sustain the vision while building coalitions to undertake the construction of what the Norwegian press would call "Vebjørn Sand's Leonardo Project."

The Norwegian Leonardo Bridge Project did not easily fall into place. Vebjørn Sand's celebrity in Norway rests on his reputation as a young painter of considerable ability who gleefully joined the public debate over the issue of the dominant Modernist orthodoxy. Sand supports rigorous technical mastery required of classical art training. The Norwegian art academies no longer taught those skills. As the Leonardo Bridge Project developed, this debate continued to grow more heated in the Norwegian press. Sand's conceptual tribute to the Renaissance thinkers, and Leonardo's vision, came under scathing criticism. Some said the bridge belonged in Disneyland; others accused Vebjørn Sand of being a fascist.

Conceptually, Vebjørn Sand sees the project as a vivid meeting between the functional and esthetical worlds. It is a reminder that the technology the human race has come to consider a necessary part of daily life, was possible only by the deep faith the great geniuses of Western art and science had in the spiritual reality of the natural world. Nature now almost trivialized by the very pervasive-ness of these inventions. The bridge unites the past with the present, and expresses the greatest and the most beautiful aspect of Renaissance art and science. That is a meeting between heaven and earth, between the spiritual and the material realms.

To the artist, the bridge is also a beautiful metaphor for the meeting between people, cultures and continents. It is in itself - in its reality - the harmonic expression of this meeting. Thus was born Vebjørn Sand's vision to build the bridge on every continent.

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Da Vinci had left sketchy instructions in his notebooks for the construction of his design. It has been suggested that he didn't intend for the bridge to be anything more than a visionary sketch. But evidence of a letter written to the Sultan, though not in Leonardo's hand, proves that it was intended as part of a millwork project. Since he hoped the Turkish prince would approve the project, he is unlikely to have presented a project that couldn't be executed.

Leonardo's design consists of a weight-bearing granite vault with a built up walkway that forms a crossing between terrain and vault. Granite is extremely strong under stress and the load force of the pressed-bow design is such that a slender and resilient span can be constructed. The flat bridge shape, which is also seen in the viaduct over the Golden Horn - described in the same terms as those between pier height and arch span - give the bridge elegance and boldness. This impression emphasizes the slim mid-portion of the bridge, which at its narrowest point, measures only 25.5 inches (65 centimeters). Towards the sides and bottom of the arch the construction thickness increases to 15 feet (4.5 meters) and an anchoring footing 42 feet (14 meters) wide flairs out on each end.

Stein Atle Haugerud, from the structural engineering firm of Dr. techn. Olav Olsen a.s., worked with Vebjørn Sand to construct computer renderings of the design, testing possible durability issues. The conclusion was that the bridge should be a pedestrian overpass to avoid unforeseen structural problems caused by traffic vibration. It would be a scaled-down version with a 300-feet (100 meters) span and a total length of 400 feet (135 meters.)

Two versions of the bridge, one in stone and one in wood, were planned. Following a tradition of bridge construction in Norwegian culture, timber was used for the Ås project. The bowed arches so critical to the elegant form were created by a process of lamination developed by the Norwegian company, Moelven Group, well known for the 1994 Lilihammar Olympic "Viking Ship" Ice Rink. Moelven also developed a new technique for preserving the bright color of the Norwegian pine. An innovative walkway material was also developed specifically for the project.

The architectural firm of Selberg Architects created the final plans for the Project.

Through the process of development, these world-class architects and engineers have joined Vebjørn Sand to create a "dream team" of experts on the history, design and structural aspects of the "Queen of Bridges" prepared to implement the global project. Sand's vision to build the bridge on each continent also includes drawing on the cultural traditions, and incorporating materials, unique to each region.

Finally, the Leonardo Bridge Project represents a historical connection between Europe and the Middle East, between Christianity and Islam. The Italian Renaissance was inspired by the scholarship of the Ottoman Empire. Leonardo, in turn, was fascinated by the Middle East. This aspect seems particularly relevant since the events of September 11, 2001, as the Leonardo Project expands into the global goodwill project Vebjørn Sand envisioned.

The Norwegian Leonardo Bridge was constructed and opened to foot and bicycle traffic on October 31, 2001. Da Vinci's vision resurrected, 500 years after the drawing was made. Vebjørn Sand is currently considering several sites in the United States for the next Leonardo Bridge Project.