6 ms·

Engineers put Leonardo da Vinci's bridge design to the test (2019)

61 points by hidden-spyder 5y ago

perihelions 5y ago
I wonder if it would have survived into the modern era, like many [0] of the compression-arch Roman bridges have. I imagine engineering history could have gone very differently, with such a crazy artifact standing as a proof-of-concept, inciting even bolder ideas. (What's the da Vinci version of steampunk called?) [0] https://en.wikipedia.org/wiki/List_of_Roman_bridges https://en.wikipedia.org/wiki/List_of_Roman_bridges Apparently there's a lot of other attempts (beside OP's) to build scaled versions of this bridge. (The article mentions a steel footpath bridge in Norway). Here's one I think is particularly interesting: a reasonably faithful replica at the 100-meter scale, built of pykrete [1] (sawdust-reinforced water-ice composite). https://www.cursor.tue.nl/en/news/2015/april/tue-team-to-build-da-vinci-bridge-with-a-span-of-50-meters/ https://www.cursor.tue.nl/en/news/2015/april/tue-team-to-bui... https://www.youtube.com/c/BridgeInIce/videos https://www.youtube.com/c/BridgeInIce/videos [1] https://en.wikipedia.org/wiki/Pykrete https://en.wikipedia.org/wiki/Pykrete I can't find a good post-mortem article, but it looks like it collapsed during construction and was abandoned. (?)
- CapitalistCartr 5y ago
  "What's the da Vinci version of steampunk called?" Clockpunk.
  - stan_rogers 5y ago
    Not even that, really. He predates the pendulum by just about a century (and I mean Galileo's discovery of its regularity, not Huygens' employment of it). Sure, there was verge-and-foliot in limited number in cathedrals and monasteries, but common clockwork - Nuremberg eggs and that sort of thing - came along shortly after Leonardo went away. Sundials and water clocks were the order of the day in Leonardo's time.
  - dredmorbius 5y ago
    I'd go with Renpunk (Renaissance Punk).
- sandworm101 5y ago
  >> I wonder if it would have survived into the modern era No. The roman bridges, the ones still up, lasted so long because they were ridiculously overbuilt. The romans lacked a full understanding and so made everything far stronger than we now know is necessary. Even with a millennia of weathering and erosion they still have more than enough strength to remain standing. Da Vinci's bridge design is more efficient and uses less material. It spreads a similar load on a lesser amount of material. If using the same materials as the romans (stone) it would not last the centuries because it would have less reserve strength to lose to weathering.
  - France_is_bacon 5y ago
    Meanwhile, here in the USA, all we hear about is how our bridges are falling apart after 50 years and that we need to spend trillions to bring them and other stuff like that up to speed. Maybe we should have ridiculously overbuilt our bridges and roads so that they will last 2000 years. I know. Crazy ideas.
    - danachow 5y ago
      There’s no free lunch. An overbuilt bridge the magnitude of a modern suspension bridge may well take 50 years to build. The romans weren’t building them that big and the projects that were that big took generations.
      - France_is_bacon 5y ago
        Yeah, but I'm not talking about bridges like the Golden Gate or Brooklyn Bridges. Those bridges will never be in danger of falling down, because bridges like that are constantly repaired and maintained. The bridges that I am talking about, and that most are talking about, are the shorter bridges. The ones that are 20 or 30 or 50 feet long - just the regular small bridges - there are thousands and thousands of them, all ready to fall down. Just looked it up, I was not even close - there are not thousands and thousands, there are more than 617,000 bridges across the United States. https://infrastructurereportcard.org/cat-item/bridges/ https://infrastructurereportcard.org/cat-item/bridges/
- Jach 5y ago
  > inciting even bolder ideas Even if it would have lasted, which I doubt, I also doubt it would have successfully inspired much, and certainly not any time before real engineering came about as a consequence of understanding physics and thus having a theory guiding and supporting work, rather than a cookbook of rules. (Like, the surviving ancient marvels notwithstanding, you can really only go so far in structures without an understanding of beam theory, stresses, even the square-cube law which wasn't articulated until Galileo.) When the architects and builders of the past (I think it's a stretch to call them engineers) veered too far from established practice, things tended to frequently collapse. A Roman example: https://en.wikipedia.org/wiki/Insula_(building) https://en.wikipedia.org/wiki/Insula_(building)
Galanwe 5y ago
I'm a bit shocked that in 2021, students rely on physically building the bridge and simulating earthquakes with moving platforms. This feels like dummy engineering. I would have expected a mechanical engineer to actually be able to prove or disprove the feasibility through math, and create a CAD model on which to apply forces simulating earthquakes, heatwaves, etc.
- rini17 5y ago
  On contrary, I am actually delighted to see the hands-on approach. Pure math is vulnerable to missed preconditions/unknown unknowns, with potentially catastrophic ramifications when it's carelessly applied to real building. You must know in advance what you're going to prove.
  - unearth3d 5y ago
    Like London's Millennium Bridge https://arstechnica.com/science/2018/10/new-study-sheds-more-light-on-what-caused-millennium-bridge-to-wobble/ https://arstechnica.com/science/2018/10/new-study-sheds-more... I agree, engineering is art + science, impossible to iron everything out theoretically.
  - Galanwe 5y ago
    > Pure math is vulnerable to missed preconditions/unknown unknowns, with potentially catastrophic ramifications Interestingly I see the opposite. I expect the replica to be full of dangerous approximations: scaled weight of the stones not realistic, friction of the material not taken into consideration, earthquake ground vibrations not properly emulated by just shaking plates, etc
    - klyrs 5y ago
      I take issue with the term "pure math" here. Engineering simulation is strictly the realm of applied math, a dark art of floating point calculations, finite element analysis, idealized material properties, etc. Pure math demands much more rigor, and gets exact answers, but the methods available cannot handle the complexity of a bridge in this lifetime.
IfOnlyYouKnew 5y ago
It not only works, but is among the most beautiful structures I've seen. Someone should really build that. It also once again makes me consider the idea that da Vinci was a time travelling physicist having the time of his life.
blunte 5y ago
You can take one fast look at the design and see where the biggest problem is going to be: the lateral (spreading) forces against the ends of the bridge will require some clever anchor or ground lock of sorts, otherwise the ends will just shove apart and the middle will collapse. Notice in the modern model, they have the ends not only anchored, but actually blocked within boundaries that prevent spreading. Other bridges have used a similar design, but they had much more of a vertical component. Then the forces at the ground were more perpendicular to the earth plane, so gravity and mass of the stones (and friction of the stones against the earth) could better prevent separation.
- sfteus 5y ago
  To be fair, even modern arch style bridges have the same concerns. For example, overhead arch bridges get around it by using ties between the ends running underneath the actual bridge itself to prevent the ends from separating. The Hernando de Soto bridge used this type of design and was recently closed for a few months because one of the ties had started to fail.
shadilay 5y ago
The headline made me think it was a different bridge of Leonardo's. https://www.researchgate.net/figure/A-design-for-a-temporary-bridge-suggested-by-Leonardo-da-Vinci_fig10_225146302 https://www.researchgate.net/figure/A-design-for-a-temporary...
blaaee 5y ago
They created one in Norway with that design I think? https://no.wikipedia.org/wiki/Da_Vinci-broen https://no.wikipedia.org/wiki/Da_Vinci-broen

61 points by hidden-spyder 5y ago

I wonder if it would have survived into the modern era, like many [0] of the compression-arch Roman bridges have. I imagine engineering history could have gone very differently, with such a crazy artifact standing as a proof-of-concept, inciting even bolder ideas. (What's the da Vinci version of steampunk called?) [0] https://en.wikipedia.org/wiki/List_of_Roman_bridges https://en.wikipedia.org/wiki/List_of_Roman_bridges Apparently there's a lot of other attempts (beside OP's) to build scaled versions of this bridge. (The article mentions a steel footpath bridge in Norway). Here's one I think is particularly interesting: a reasonably faithful replica at the 100-meter scale, built of pykrete [1] (sawdust-reinforced water-ice composite). https://www.cursor.tue.nl/en/news/2015/april/tue-team-to-build-da-vinci-bridge-with-a-span-of-50-meters/ https://www.cursor.tue.nl/en/news/2015/april/tue-team-to-bui... https://www.youtube.com/c/BridgeInIce/videos https://www.youtube.com/c/BridgeInIce/videos [1] https://en.wikipedia.org/wiki/Pykrete https://en.wikipedia.org/wiki/Pykrete I can't find a good post-mortem article, but it looks like it collapsed during construction and was abandoned. (?)

CapitalistCartr 5y ago
"What's the da Vinci version of steampunk called?" Clockpunk.
- stan_rogers 5y ago
  Not even that, really. He predates the pendulum by just about a century (and I mean Galileo's discovery of its regularity, not Huygens' employment of it). Sure, there was verge-and-foliot in limited number in cathedrals and monasteries, but common clockwork - Nuremberg eggs and that sort of thing - came along shortly after Leonardo went away. Sundials and water clocks were the order of the day in Leonardo's time.
- dredmorbius 5y ago
  I'd go with Renpunk (Renaissance Punk).
sandworm101 5y ago
>> I wonder if it would have survived into the modern era No. The roman bridges, the ones still up, lasted so long because they were ridiculously overbuilt. The romans lacked a full understanding and so made everything far stronger than we now know is necessary. Even with a millennia of weathering and erosion they still have more than enough strength to remain standing. Da Vinci's bridge design is more efficient and uses less material. It spreads a similar load on a lesser amount of material. If using the same materials as the romans (stone) it would not last the centuries because it would have less reserve strength to lose to weathering.
- France_is_bacon 5y ago
  Meanwhile, here in the USA, all we hear about is how our bridges are falling apart after 50 years and that we need to spend trillions to bring them and other stuff like that up to speed. Maybe we should have ridiculously overbuilt our bridges and roads so that they will last 2000 years. I know. Crazy ideas.
  - danachow 5y ago
    There’s no free lunch. An overbuilt bridge the magnitude of a modern suspension bridge may well take 50 years to build. The romans weren’t building them that big and the projects that were that big took generations.
    - France_is_bacon 5y ago
      Yeah, but I'm not talking about bridges like the Golden Gate or Brooklyn Bridges. Those bridges will never be in danger of falling down, because bridges like that are constantly repaired and maintained. The bridges that I am talking about, and that most are talking about, are the shorter bridges. The ones that are 20 or 30 or 50 feet long - just the regular small bridges - there are thousands and thousands of them, all ready to fall down. Just looked it up, I was not even close - there are not thousands and thousands, there are more than 617,000 bridges across the United States. https://infrastructurereportcard.org/cat-item/bridges/ https://infrastructurereportcard.org/cat-item/bridges/
Jach 5y ago
> inciting even bolder ideas Even if it would have lasted, which I doubt, I also doubt it would have successfully inspired much, and certainly not any time before real engineering came about as a consequence of understanding physics and thus having a theory guiding and supporting work, rather than a cookbook of rules. (Like, the surviving ancient marvels notwithstanding, you can really only go so far in structures without an understanding of beam theory, stresses, even the square-cube law which wasn't articulated until Galileo.) When the architects and builders of the past (I think it's a stretch to call them engineers) veered too far from established practice, things tended to frequently collapse. A Roman example: https://en.wikipedia.org/wiki/Insula_(building) https://en.wikipedia.org/wiki/Insula_(building)

Galanwe 5y ago

I'm a bit shocked that in 2021, students rely on physically building the bridge and simulating earthquakes with moving platforms. This feels like dummy engineering. I would have expected a mechanical engineer to actually be able to prove or disprove the feasibility through math, and create a CAD model on which to apply forces simulating earthquakes, heatwaves, etc.

rini17 5y ago
On contrary, I am actually delighted to see the hands-on approach. Pure math is vulnerable to missed preconditions/unknown unknowns, with potentially catastrophic ramifications when it's carelessly applied to real building. You must know in advance what you're going to prove.
- unearth3d 5y ago
  Like London's Millennium Bridge https://arstechnica.com/science/2018/10/new-study-sheds-more-light-on-what-caused-millennium-bridge-to-wobble/ https://arstechnica.com/science/2018/10/new-study-sheds-more... I agree, engineering is art + science, impossible to iron everything out theoretically.
- Galanwe 5y ago
  > Pure math is vulnerable to missed preconditions/unknown unknowns, with potentially catastrophic ramifications Interestingly I see the opposite. I expect the replica to be full of dangerous approximations: scaled weight of the stones not realistic, friction of the material not taken into consideration, earthquake ground vibrations not properly emulated by just shaking plates, etc
  - klyrs 5y ago
    I take issue with the term "pure math" here. Engineering simulation is strictly the realm of applied math, a dark art of floating point calculations, finite element analysis, idealized material properties, etc. Pure math demands much more rigor, and gets exact answers, but the methods available cannot handle the complexity of a bridge in this lifetime.

IfOnlyYouKnew 5y ago

It not only works, but is among the most beautiful structures I've seen. Someone should really build that. It also once again makes me consider the idea that da Vinci was a time travelling physicist having the time of his life.

blunte 5y ago

You can take one fast look at the design and see where the biggest problem is going to be: the lateral (spreading) forces against the ends of the bridge will require some clever anchor or ground lock of sorts, otherwise the ends will just shove apart and the middle will collapse. Notice in the modern model, they have the ends not only anchored, but actually blocked within boundaries that prevent spreading. Other bridges have used a similar design, but they had much more of a vertical component. Then the forces at the ground were more perpendicular to the earth plane, so gravity and mass of the stones (and friction of the stones against the earth) could better prevent separation.

sfteus 5y ago
To be fair, even modern arch style bridges have the same concerns. For example, overhead arch bridges get around it by using ties between the ends running underneath the actual bridge itself to prevent the ends from separating. The Hernando de Soto bridge used this type of design and was recently closed for a few months because one of the ties had started to fail.

shadilay 5y ago

The headline made me think it was a different bridge of Leonardo's. https://www.researchgate.net/figure/A-design-for-a-temporary-bridge-suggested-by-Leonardo-da-Vinci_fig10_225146302 https://www.researchgate.net/figure/A-design-for-a-temporary...

blaaee 5y ago

They created one in Norway with that design I think? https://no.wikipedia.org/wiki/Da_Vinci-broen https://no.wikipedia.org/wiki/Da_Vinci-broen