Commissioned by an Ottoman sultan, the structure was 10 times larger than any built at the time – and more earthquake resistant.
By Guilherme Eler
Oct 18, 2019, 3:52 PM
Leonardo da Vinci was known for his inventiveness, but not so much for completing projects – as we already told here at SUPER. Many of the creation schemes that the Italian sketched never left the paper, or were just introductory – drawings that, if they had to serve as a basis for inventions, would probably need to be further detailed to guide the hands-on.
Among flying machines, statues, cannons, parachutes and diving suits, another curious piece of engineering attributed to the author is a bridge project. Da Vinci is believed to have proposed it after Sultan Bajazeto II, the Ottoman leader, requested a building idea linking the capital Constantinople with Galata, the empire's financial center. After passing anonymous centuries, the draft was found in 1952.
It would be, at the time, the largest bridge in the world. The project was ambitious and, on paper, designed to be 280 meters long – 10 times longer than structures of its kind in the early 16th century – passing over a river estuary called the Golden Horn. And interestingly, if it had been put into practice, it could have been a success.
That's what MIT researchers found. His idea was, based on da Vinci's notes in 1502, to try to make a working bridge prototype.
The group took into account in the analysis not only the drafts of the Renaissance inventor, but also the materials and construction methods used at the time and the geological conditions of the region that would receive such a bridge. The result was a model made of 126 pieces on a 3D printer, and scale 1 to 500 – 1 centimeter of the model represent 500 in real life, which makes the prototype about 80 centimeters.
Bridge supports built in the days of Leonardo da Vinci used to take the semicircle shape. Because of this, such a large bridge would in theory need at least 10 pillars.
Not in the head of the Italian genius. Its bridge concept was quite different, a kind of unique bow (like a tiara) that would be tall enough for a boat to pass underneath without major mishaps.
In addition, da Vinci's elongated “X” design reinforced the sides of the structure. Increasing support had an antidote to a common problem of the time: there are reports of several bridges collapsing at the same points, due to the lack of balance – and the high number of earthquakes that affected the region.
How do you highlight the Smithsonian Museum magazine, it is unlikely that the same building model will be repeated in an actual engineering work. The main reason is that getting a material strong enough to build the bridge block by block, as the researchers at MIT emulated, would be somewhat costly. Interestingly, a reinterpretation project by da Vinci in 1502 already exists: a pedestrian bridge opened in Norway in 2001 – with the name “da Vinci”, as it could not fail to be. Instead of small stone blocks, however, it is made of wood and steel.
“This is a very solid engineering concept. It was very well thought out, ”says Karli Bast, a newly graduated engineer at MIT who participated in the creation of the prototype, in a statement.
Once it proved functional, the main question about the Da Vinci Bridge became another. “Was this sketch freehand done in about 50 seconds, or did it require him to really sit down and think about it calmly? It's hard to know, ”he points out.
Given the effectiveness of the design and the importance of who commissioned the project, however, the best hypothesis is that Leonardo actually planned it. “He knew how the physical world worked,” adds Bast. Of that, there is no doubt.