Testing Leonardo da Vinci’s bridge

[plague311]

I wasn't sure where to put this so I figure I'll put it here as it kind of relates to "technology".

MIT researchers dug into one of Da Vinci's previous bridge designs to see if it would work. Apparently, it would have!

According to a team of researchers at MIT, who built a detailed scale model to test that hypothesis, the answer is yes.

...

Sultan Bayezid II of Turkey in 1502...wanted a bridge to span a river estuary known as the Golden Horn to connect Constantinople (now Istanbul) to the neighboring town of Galata—a bridge span of about 919 feet (280 meters), roughly ten times longer than a typical bridge of that era, according to co-author Karly Bast, a graduate student at MIT.

...

The group first determined how best to slice up the shape of the bridge into individual blocks and then used a 3D printer to make 126 blocks to build a scale model, the better to recreate the complex geometry of Leonardo's original design. They used a scaffolding structure to support their bridge as it was being assembled, removing it once the keystone at the top of the arch was in place. And the structure was stable, just as Leonardo envisioned.

Anyway, I don't want to quote the whole article. It's rather lengthy but it was worth the read to me. I'm not an architecture or engineering junkie or anything, but I do like seeing old\historic\ancient theories tested.

Da Vinci was an absolute genius to me for several reasons, and this just proves he was far, far ahead of his time.

 

[MRC_Hans]

I wasn't sure where to put this so I figure I'll put it here as it kind of relates to "technology".

MIT researchers dug into one of Da Vinci's previous bridge designs to see if it would work. Apparently, it would have!



Anyway, I don't want to link the whole article. It's rather lengthy but it was worth the read to me. I'm not an architecture or engineering junkie or anything, but I do like seeing old\historic\ancient theories tested.

Da Vinci was an absolute genius to me for several reasons, and this just proves he was far, far ahead of his time.

Mmm, not to belittle da Vinci, but in his time, bridges had been constructed for at east a thousand years.

Hans

 

[plague311]

Mmm, not to belittle da Vinci, but in his time, bridges had been constructed for at east a thousand years.

Hans

Absolutely not in doubt, but I believe the difference is the way this bridge was to be built was the amazing part.

 

[Roboramma]

Mmm, not to belittle da Vinci, but in his time, bridges had been constructed for at east a thousand years.

Hans

From the article: "Had Leonardo's bridge ever been built, it would have been the longest bridge span of its time."

Another aspect:

Masonry bridges in that era were usually built with a series of semicircular arches, but a span as long as the sultan required would need to be bolstered by at least ten piers. That meant ships wouldn't be able to pass beneath it. Leonardo envisioned a bridge "as high as a building" with just a single arch, relying on pure compression for structural stability, without any additional fasteners or mortar to hold the stone together.

So it would have been the longest bridge span of it's time, and done with a single arch in order to allow ships to pass beneath it. Seems impressive to me.

 

[rjh01]

There is one problem. Things do not scale well. A small model may work well, but make it much bigger and the thing will fall apart. Like make something twice as long and you will need to make it twice as thick as well. That makes it four times heavier.

 

[Steve]

There is one problem. Things do not scale well. A small model may work well, but make it much bigger and the thing will fall apart. Like make something twice as long and you will need to make it twice as thick as well. That makes it four times heavier.

Scaling could be an issue as you say, but I would think that an outfit such as the MIT engineering dept would consider such a basic issue when forming their conclusion.

The group appear to have published a paper in their work that is likely much more detailed than “we built this model and it worked”.

 

[mgidm86]

If it's been invented, Leo thought of it already.

 

[theprestige]

Scaling could be an issue as you say, but I would think that an outfit such as the MIT engineering dept would consider such a basic issue when forming their conclusion.



The group appear to have published a paper in their work that is likely much more detailed than “we built this model and it worked”.

Theranos. An institution no less prestigious than Stanford University produced a professor and his protégé who absolutely did not deserve the cachet. I'm deeply skeptical of the genius of college students, no matter how impressive the reputation of their alma mater.

 

[Steve]

Theranos. An institution no less prestigious than Stanford University produced a professor and his protégé who absolutely did not deserve the cachet. I'm deeply skeptical of the genius of college students, no matter how impressive the reputation of their alma mater.

I am somewhat skeptical of the genius of college students. This exercise required no genius. That ended when DaVinci finalized his plans. The matter at hand is largely an engineering analysis of an existing design, conducted by engineering students.

My response to rjh01 was re the issue of scaling, an issue that any first year engineering student at any school would be well aware of. No genius required.

 

[cullennz]

Went to a da Vinci exhibition on loan from his museum in Florence a few years ago.

It was all of his inventions, and drawings etc.

Basically all the bits that aren't his paintings (which I have zero interest in).

One of the coolest things I have been to.

Recommend highly to those in Europe to visit (assuming it is not on loan)

 

[cullennz]

Stats - Help with arguement I am having with my self.

..

 

[sphenisc]

"Leonardo never got the commission to build his bridge for the sultan."

Not the last time a Turkish leader screwed over a strong and stable genius.

 

[plague311]

I am somewhat skeptical of the genius of college students. This exercise required no genius. That ended when DaVinci finalized his plans. The matter at hand is largely an engineering analysis of an existing design, conducted by engineering students.

My response to rjh01 was re the issue of scaling, an issue that any first year engineering student at any school would be well aware of. No genius required.

The software they used was fairly advanced as well. Per the second paragraph of the linked article:

Several years ago, he adapted particle spring modeling—the same tool often used to recreate the movement of fabrics and hair in CGI animation (like the movement of Yoda's cloak in his battle with Darth Sidious in Revenge of the Sith)—to model those architectural features. Ochsendorf's version reversed the model so that instead of modeling tension, it modeled compression. The software program featured virtual "masses" at key "nodes" connected by virtual "springs," which bounce around until they find equilibrium, indicating that the design can support the requisite loads.

 

[Dr. Keith]

To me, the real challenge that Leo faced was creating the technology to build the bridge.

And that likely wasn't a risk the Sultan was willing to take.

Also, nommed sphenisc's post. Too good.

 

[ahhell]

There is one problem. Things do not scale well. A small model may work well, but make it much bigger and the thing will fall apart. Like make something twice as long and you will need to make it twice as thick as well. That makes it four times heavier.

Scaling could be an issue as you say, but I would think that an outfit such as the MIT engineering dept would consider such a basic issue when forming their conclusion.

The group appear to have published a paper in their work that is likely much more detailed than “we built this model and it worked”.

Scaling models is something quite routine in engineering, I'd be surprised if they had not accounted for it. I wouldn't be surprised to find some caveat to the effect of, "..........but not with materials available at the time,"which seems to be common to some of his more fanciful designs.

Also, it appears to be designed by taking a section of a circle as the arch, which essentially works in the same manner as a semi circular arch, so there's nothing extraordinary about it from a modern standpoint. It would demonstrate Da Vinci's genius if he was the first person to think of it.

Edit, as Dr Keith said, the real challenge would be building it. At the time they basically built wood falsework to support the masonry of an arch until it was fully constructed, the remove the shoring and you have a fancy new bridge. That bridge would have used a lot of trees.

 

[MRC_Hans]

Da Vinci's bridge is basically an arch. Such were known long before him. Example: https://www.azernews.az/culture/126857.html

I'm really not challenging the fact that Leonardo da Vinci was a genius, but in the present, he is often overrated. Many of his designs were not new, and some others were unrealistic.

Hans

 

[Dr. Keith]

Da Vinci's bridge is basically an arch. Such were known long before him. Example: https://www.azernews.az/culture/126857.html

I'm really not challenging the fact that Leonardo da Vinci was a genius, but in the present, he is often overrated. Many of his designs were not new, and some others were unrealistic.

Hans

I think the assertion is that his was a much flatter arch that would have obviated the need for multiple small spans (such as the one you linked to). On long flattish arch gives more height in the middle without the obstructions to river traffic caused by multiple small spans.

I think it also flared on each side to provide some lateral support that was necessary due to its length.

The design still looks rather modern to my eye and I would not have been shocked to read that it was designed sometime mid-century or later. Obviously it wouldn't have been as ground breaking at that time, but it has that aesthetic.

 

[Roboramma]

Scaling models is something quite routine in engineering, I'd be surprised if they had not accounted for it. I wouldn't be surprised to find some caveat to the effect of, "..........but not with materials available at the time,"which seems to be common to some of his more fanciful designs.

If you read the article the point of the exercise was to demonstrate that it could have been done with the materials and techniques available at the time.

One thing that's not really pointed out but is in there is that Leonardo originally suggested using masonry as the structural material for the bridge, but they find that wouldn't be strong enough and instead suggest the use of stone.

ETA:

Norway's pedestrian bridge is built with modern material (glued laminated timber, or glulam). In Leonardo's time, masonry was the preferred material. Masonry will break easily under tension, yet it can withstand huge compressive forces. So that was Leonardo's choice of material when he pitched his bridge design to the Ottoman ruler Sultan Bayezid II of Turkey in 1502.

To test Leonardo's bridge design, Ochsendorf, Bast, and co-author Michelle Xin (an undergraduate at MIT) pored over historical documents to glean as much information as possible about materials and construction methods common in the early 16th century, as well as the geologic conditions at the original proposed site for the bridge (the Golden Horn). They concluded the bridge would indeed have been made of stone, since wood or brick would not have been able to withstand the load of a such a long span.

 

[MRC_Hans]

I think the assertion is that his was a much flatter arch that would have obviated the need for multiple small spans (such as the one you linked to). On long flattish arch gives more height in the middle without the obstructions to river traffic caused by multiple small spans.

I think it also flared on each side to provide some lateral support that was necessary due to its length.

The design still looks rather modern to my eye and I would not have been shocked to read that it was designed sometime mid-century or later. Obviously it wouldn't have been as ground breaking at that time, but it has that aesthetic.

I agree, and that was actually my point: This is not an invention, just an excellent improvement on an existing and well-used design. The problem for the design is that a flatter arch will put a correspondingly higher pressure not only on the elements of the arch itself, but also on the foundations (which this design will try to press apart).

This is one of my reservations about many da Quirm ... ops da Vinci designs: They are brilliant, but rather speculative.

Hans

 

[Dr. Keith]

I agree, and that was actually my point: This is not an invention, just an excellent improvement on an existing and well-used design.

A minor quibble: most inventions are just excellent improvements on existing designs. Hell, some inventions are just minor improvements on existing designs.

There are more patent applications on golf tees than you can shake a fist at.