"Il Cavallo," the huge equine statue Leonardo Da Vinci never got to make, wasn't plagued by technical problems as was widely believed, a new multidisciplinary research has revealed.
On the contrary, Da Vinci's plan for the largest equestrian statue in the world was a perfectly feasible project which, if completed, would have probably been his greatest legacy, more than ''The Last Supper'' or any other work.
Commissioned in 1482 by Lodovico Sforza, duke of Milan, in honor of his father Francesco, the massive bronze horse took Leonardo 17 years of research, but was never completed.
Indeed, when the full-scale clay model was finally ready to be cast in a single operation in 1499, all the needed bronze was used to make cannons for an imminent war against the King of France.
The molds were lost and the clay model was reduced to rubble by the invading French soldiers.
Although Leonardo never stopped mourning the "horse-that-never-was," engineers have always believed the daring plan to make the largest single-pouring cast ever would have failed because of technical problems.
"How would you handle such a large quantity of hot bronze, and how would balance a huge structure weighing many tons on three legs? Advanced computing and precise data stored in Leonardo's manuscripts have now provided the answers," Paolo Galluzzi, director of the Institute and Museum of the History of Science in Florence, Italy, told Discovery News.
Combining Leonardo's notes and computational fluid dynamics software, Galluzzi's team has shown that the 24-foot-high, 70-ton bronze horse would have been successfully cast in a single pouring in just 165 seconds.
"The project was totally feasible in the two different versions that Da Vinci had conceived, with the horse cast either in horizontal or vertical position. However, he had to abandon the leg up position since a 20-meter-deep casting pit would have not been safe," Galluzzi said.
To build his trotting horse, Leonardo used the so-called indirect casting technique, which allows the re-use of negatives prepared for the construction of the casting core.
Well known to the Greeks since the seventh century B.C., the method was not known to Renaissance artists as no description had survived from antiquity.
A scientific and artistic challenge for Leonardo's genius, the project examined all the critical aspects in the casting procedure.
To reach the perfect temperature and timing, Da Vinci even devised a system of temporized furnaces.
"The furnaces were opened according to a determined sequence. They were controlled by pyrotechnic sensors which fired as the molten bronze reached them, sending out the signal to open the next furnace," Galluzzi said.
The Renaissance master also considered all the possible critical points in the statue, at the delicate time when the molten bronze flows from the furnaces into the mold.
"The model has revealed that everything was carefully planned. It turned out that the most critical parts in the casting, where the bronze cools faster, are those which are the least important for the horse's balance," Alessandro Incognito, director at XC Engineering, the company that carried the casting simulation, told Discovery News.
The 3-D models showed that the molten bronze would have filled the molds needed for the huge statue in less than 165 seconds and all that metal would have weighed 70 tons — exactly the amount that Leonardo had calculated.
According to Alessandro Vezzosi, director of the Museo Ideale in the Tuscan town of Vinci, where the artist was born in 1452, the study is important as it highlights aspects which are not possible to investigate with traditional historical research tools.
"It presents an interesting way of approaching historical art projects since it puts together contemporary technology and historical records," Vezzosi told Discovery News.
The results of Galluzzi and colleagues' research will be displayed at an exhibition at the Florence museum, while a spectacular event is planned at Milan's Expo 2015.
"Now that our research has proved that Leonardo's project was feasible, we are planning to finally cast his horse right in the town where he wanted it to stand," Galluzzi said.