MIT Researchers 3D Print a Bridge Imagined by Leonardo da Vinci in 1502— and Prove That It Actually Works

Pho­to by Gretchen Ertl, via MIT News

Unfor­tu­nate though it may be for the dream­ers of the world, we’re all judged not by what we imag­ine, but what we actu­al­ly do. This goes dou­ble for those specif­i­cal­ly tasked with cre­at­ing things in the phys­i­cal envi­ron­ment, from engi­neers and archi­tects to inven­tors and artists. Leonar­do da Vin­ci, the orig­i­nal “Renais­sance man,” was an engi­neer, archi­tect, inven­tor, artist, and more besides, and five cen­turies after his death we con­tin­ue to admire him for not just the works of art and tech­nol­o­gy he real­ized dur­ing his life­time, but also the ones that nev­er made it off his draw­ing board (or out of his note­books). And as we con­tin­ue to dis­cov­er, many of the lat­ter weren’t just flights of fan­cy, but gen­uine inno­va­tions ground­ed in real­i­ty.

Take the bridge Leonar­do pro­posed to Sul­tan Bayezid II, who in 1502 had “sent out the Renais­sance equiv­a­lent of a gov­ern­ment RFP (request for pro­pos­als), seek­ing a design for a bridge to con­nect Istan­bul with its neigh­bor city Gala­ta,” writes MIT News’ David L. Chan­dler. Writ­ing to the sul­tan, Leonar­do describes his design as “a mason­ry bridge as high as a build­ing, and even tall ships will be able to sail under it.”

At the time, such bridges required the sup­port of piers all along their spans, which pre­vent­ed large ships from pass­ing under­neath. But Leonar­do’s design would do the job with only “a sin­gle enor­mous arch.” About ten times longer than the typ­i­cal bridge of the ear­ly 16th cen­tu­ry, it took a page from the bridges of ancient Rome, designed as it was to “stand on its own under the force of grav­i­ty, with­out any fas­ten­ers or mor­tar to hold the stone togeth­er.”

Image via Wiki­me­dia Com­mons

Alas, Leonar­do, who had bet­ter luck with Ital­ian patrons, did­n’t win this par­tic­u­lar com­mis­sion. His bridge design must at least have impressed the sul­tan with its sheer ambi­tion, but would it have held up? A team at MIT con­sist­ing of grad­u­ate Kar­ly Bast, pro­fes­sor John Ochsendorf, and under­grad­u­ate Michelle Xie recent­ly put it to the test, scru­ti­niz­ing the mate­r­i­al Leonar­do left behind, repli­cat­ing the geo­log­i­cal con­di­tions of the pro­posed site, and build­ing a 1:500 scale mod­el out of 126 3D-print­ed blocks. Not only could the mod­el bear weight using only the strength of its own geom­e­try, the design also came with oth­er fea­tures, such as sta­bi­liz­ing abut­ments (which Chan­dler com­pares to the legs of “a stand­ing sub­way rid­er widen­ing her stance to bal­ance in a sway­ing car”) to keep the bridge upright in that earth­quake-prone area of mod­ern-day Turkey.

That par­tic­u­lar loca­tion did­n’t get a bridge until 1845, when Valide Sul­tan ordered the con­struc­tion of the first, wood­en, Gala­ta Bridge. It stood for 18 years until its replace­ment by anoth­er wood­en bridge, part of an infra­struc­ture-build­ing push before Napoleon III’s vis­it to Istan­bul. The third Gala­ta Bridge, com­plet­ed in 1875 from a design by a British engi­neer­ing firm, float­ed on pon­toons. The fourth was a Ger­man-designed float­ing bridge in use from 1912 until a fire dam­aged it in 1992. Only the fifth and cur­rent Gala­ta Bridge, with its tram tracks above, its pedes­tri­an­ized deck full of shops and mar­ket spaces below, and it draw­bridge sec­tion in the mid­dle, was built by a Turk­ish com­pa­ny. In all its iter­a­tions, the Gala­ta Bridge has become one of Istan­bul’s cul­tur­al ref­er­ence points and major attrac­tions as well — not that hav­ing been designed by Leonar­do would have hurt its image any.

via MIT News/Pop­u­lar Mechan­ics

Relat­ed Con­tent:

How to Build Leonar­do da Vinci’s Inge­nious Self-Sup­port­ing Bridge: Renais­sance Inno­va­tions You Can Still Enjoy Today

Leonar­do da Vin­ci Draws Designs of Future War Machines: Tanks, Machine Guns & More

Watch Leonar­do da Vinci’s Musi­cal Inven­tion, the Vio­la Organ­ista, Being Played for the Very First Time

An Ani­mat­ed His­to­ry Of Avi­a­tion: From Leonar­do da Vinci’s Sketch­es to Apol­lo 11

Leonar­do da Vinci’s Huge Note­book Col­lec­tions, the Codex Forster, Now Dig­i­tized in High-Res­o­lu­tion: Explore Them Online

A Com­plete Dig­i­ti­za­tion of Leonar­do Da Vinci’s Codex Atlanti­cus, the Largest Exist­ing Col­lec­tion of His Draw­ings & Writ­ings

Based in Seoul, Col­in Mar­shall writes and broad­casts on cities, lan­guage, and cul­ture. His projects include the book The State­less City: a Walk through 21st-Cen­tu­ry Los Ange­les and the video series The City in Cin­e­ma. Fol­low him on Twit­ter at @colinmarshall or on Face­book.