The Magic of The Da Vinci Bridge

 

The Magic of The Da Vinci Bridge

 

The name Leonardo da Vinci is very well-known amongst science and art lovers. Although his name is synonymous with the painting called “Mona Lisa”, his repute and contributions however, are not limited to that. Da Vinci’s life and his work are intriguing, to say the least. From designing siege defenses to machine guns, automobiles to flying machines, catapults to water lifting devices, Da Vinci’s proposed list of inventions only go to further demonstrate that he, by all means was a genius. But as civil engineering enthusiasts, the most interesting design that Da Vinci came up with is surely his ingenious Self-Supporting Bridge. He came up with an amazing design of a bridge that unfortunately never saw the light of day but its design and astuteness are something that still leaves engineers today amazed.

Leonardo drafted his proposal in response to Sultan Bayezid II’s 1502 appeal for bridge designs. Bayezid, ruler of the Ottoman Empire, wanted to connect the cities of Constantinople and Galata, which were separated by a river estuary called the Golden Horn. The original design in show in the picture below.

Leonardo da Vinci creator QS:P170,Q762, Leonardo Bridge, marked as public domain, more details on Wikimedia Commons

The bridge would have been over 900 feet long any traditional bridge at that period of time would have required several piers in order to support the weight of the bridge itself. This would prevent the passage of ships form underneath the bridge with ease. Da Vinci’s design was ingenious because it required no piers and could self-sustain its weight thereby allowing easy passage to ships underneath the bridge. However, the complicate plans and design presented to the Sultan was never put to practice and hence the bridge was never built. The envisioned bridge would have looked something like this.

Lourakis (talk), Leonardo da Vinci Golden Horn Bridge model right, CC BY-SA 3.0

It is quite sad that Da Vinci’s proposed bridge was never put to practice. But centuries after his death, enthusiasts still study and marvel at his inventive bridge design.

But how exactly would this bridge work ?

In 2019 a group of MIT students created a scale model of the Da Vinci Bridge and found that the proposed design would have been successful. The magic of the Da Vinci Bridge lies in attributing the forces that the bridge needs to take into each member. The shear force exerted by the loads on the bridge bends the beams on the top of the bridge, forcing them to make the beam/poles connections tighten, therefore increasing the stability of the bridge. Hence the structural soundness of the bridge would depend on the shear strength of the material itself. As long as all the member of the bridge were sound, the bridge would hold its own weight as well as the load of the pedestrians. This does not mean that the bridge would only get stronger with time, but that the bridge would only function as long as the members in it would not break apart.

Having a little trouble understanding ? Here's a little DIY Project you can do to really understand how it works.

It is basically how Da Vinci presented his plans to construct his bridge. Where the construction units would be either timbers of block of stones with notches made precisely so that the building units would fit together and would not easily fail under the lateral load.

Today, life size bridges that take inspiration from his design also seen in various countries around Europe.

LEONARDOBROEN. BY: AKERSHUS REISELIVSRÅD

Da Vinci Bridge in Leonardo da Vinci Garden. Photo: Léonard de Serres

With the modern advancements in the construction sector and the use of much lighter and convenient materials, it is highly unlikely we will see a bridge exactly like the one Da Vinci envisioned which was over 900 feet long. His idea however was not mistaken. For Leonardo Da Vinci to envision such a bridge with the science and resources of his era only goes to further prove how familiar he was with the science of forces and geometry. 

Before we end, you must have learned a little more about the Da Vinci Bridge than you did before. But one question looms in mind, how strong can a bridge with planks of wood without any vertical support truly be ? Well, to answer that I leave you with this video of a replica bridge constructed in Stuttgart, Germany. May it leave you as bamboozled as it left me .