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I like this quote. We have a medieval bridge near to our house (1000 years old perhaps), it's incredibly solidly built, but could you call it well-engineered?

I like this quote. We have a medieval bridge near to our house (1000 years old perhaps), it's incredibly solidly built, but could you call it well-engineered? It's a subtle distinction that I don't think many in the digital realm quite grasp either i.e. far too many over-engineered technical solutions for features and products that aren't even desired

lukan 3y ago
"but could you call it well-engineered" If it is still standing after 1000 years, I would say yes. You cannot build a bridge out of stones with bad engineering - it would collapse under its own weight. edit: does "well engineered" now means over engineered to some?
- jack_riminton 3y ago
  "If it is still standing after 1000 years, I would say yes" but what if they included far more material in areas where it wasn't needed, skimped on other areas and it fell down tomorrow? It's almost a philosophical question, and it's true that the bridge builders happened across a solid design by accident. But I think the true definition of engineering has to encompass a level of efficiency through design, calculation and rationalization. In other words, echoing what the original commenter said, including only what is barely necessary.
  - lukan 3y ago
    "and it's true that the bridge builders happened across a solid design by accident" Or by experience and learning from other sucessful bridges? Stone bridges were not new in the year 1000. There is a roman bridge that was allmost completely surviving all this time, till it was blown up in WW2: https://en.m.wikipedia.org/wiki/Ponte_Pietra_(Verona) https://en.m.wikipedia.org/wiki/Ponte_Pietra_(Verona) If they wanted a cheap solution, they would have used wood. But wood does not last a 1000 years. Personally I salute anyone, who can build something that lasts that long. "including only what is barely necessary." And "barely necessary" in solid engineering includes lots of safety margins. Not barely standing. And yes, that includes not using more than you need, because the more material you use, the heavier your bridge is -> the greater are the forces on the structure itself even with no one passing over it. There are some fun games out there on various plattforms, google "bridge builder" Not a scientific simulation of course, but they do show the concept.
  - throw0101c 3y ago
    > But I think the true definition of engineering has to encompass a level of efficiency through design, calculation and rationalization. The 1000 year medieval bridge we're talking about could have been an efficient design for its time.
    - salawat 3y ago
      When you'd be expected to stand under it while the local army/militia marched over it, incentives tended to align quite handily.
  - kwhitefoot 3y ago
    > only what is barely necessary. But then one must make clear: necessary for what.
  - rightbyte 3y ago
    > and it's true that the bridge builders happened across a solid design by accident. I think there is a great overlap between "holds for whatever scheme the prefecture will do to test it while I stand under" and "holds for a thousand years". There is like a limit where fatigue stress stops being a thing in a cycle graph. Many failure modes is due to penny wise cost cutting.
- onetimeuse92304 3y ago
  I like to tell people that all engineering is about tradeoffs. People who engineered bridges during Roman Empire had different tradeoffs to consider than people who were building bridges in 20th century. Standing for a thousand years is rarely an ultimate goal when engineering a bridge although it is possible that Romans planned for longer timescales than us. If we decided to build like Romans did, there would likely be very little infrastructure and many structures would simply be impossible to construct.
  - lukan 3y ago
    "If we decided to build like Romans did, there would likely be very little infrastructure" Why? The romans build lots of infrastructure. Roads, sewage, irrigation, .. and they used the materials and technics of their time. Can't we really do better today, with all our advanced technology? Or can't we, because everything has to be cheap, cheap, cheap? I mean, the romans used slaves. That is cheap. But we have machines.
    - lotsofpulp 3y ago
      How much population did the Romans build for? How much weight were the Romans subjecting their structures to, and at what acceleration/deceleration? Do you know the movements of the supply and demand curves of the materials required since Roman times? These types of hypotheticals are a waste of time, and only serve to illustrate hubris, as if something as complicated as comparing Roman construction and resources to modern day construction and resources could be possible.
      - lukan 3y ago
        "as if something as complicated as comparing Roman construction and resources to modern day construction and resources could be possible." Well, one can compare the results. Personally I like things that are build solid and can last a 1000 years. But I don't think I said the romans build better. They just had a different intention: long lasting.
        3y ago
kwhitefoot 3y ago
> could you call it well-engineered? What is well engineered depends on the goals and the limitations of the state of the art at the time. I would say that a thousand year old bridge might count as well engineered if the goal was a bridge that had a low total lifetime cost.
deleted 3y ago
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lukan 3y ago

"but could you call it well-engineered" If it is still standing after 1000 years, I would say yes. You cannot build a bridge out of stones with bad engineering - it would collapse under its own weight. edit: does "well engineered" now means over engineered to some?

jack_riminton 3y ago
"If it is still standing after 1000 years, I would say yes" but what if they included far more material in areas where it wasn't needed, skimped on other areas and it fell down tomorrow? It's almost a philosophical question, and it's true that the bridge builders happened across a solid design by accident. But I think the true definition of engineering has to encompass a level of efficiency through design, calculation and rationalization. In other words, echoing what the original commenter said, including only what is barely necessary.
- lukan 3y ago
  "and it's true that the bridge builders happened across a solid design by accident" Or by experience and learning from other sucessful bridges? Stone bridges were not new in the year 1000. There is a roman bridge that was allmost completely surviving all this time, till it was blown up in WW2: https://en.m.wikipedia.org/wiki/Ponte_Pietra_(Verona) https://en.m.wikipedia.org/wiki/Ponte_Pietra_(Verona) If they wanted a cheap solution, they would have used wood. But wood does not last a 1000 years. Personally I salute anyone, who can build something that lasts that long. "including only what is barely necessary." And "barely necessary" in solid engineering includes lots of safety margins. Not barely standing. And yes, that includes not using more than you need, because the more material you use, the heavier your bridge is -> the greater are the forces on the structure itself even with no one passing over it. There are some fun games out there on various plattforms, google "bridge builder" Not a scientific simulation of course, but they do show the concept.
- throw0101c 3y ago
  > But I think the true definition of engineering has to encompass a level of efficiency through design, calculation and rationalization. The 1000 year medieval bridge we're talking about could have been an efficient design for its time.
  - salawat 3y ago
    When you'd be expected to stand under it while the local army/militia marched over it, incentives tended to align quite handily.
- kwhitefoot 3y ago
  > only what is barely necessary. But then one must make clear: necessary for what.
- rightbyte 3y ago
  > and it's true that the bridge builders happened across a solid design by accident. I think there is a great overlap between "holds for whatever scheme the prefecture will do to test it while I stand under" and "holds for a thousand years". There is like a limit where fatigue stress stops being a thing in a cycle graph. Many failure modes is due to penny wise cost cutting.
onetimeuse92304 3y ago
I like to tell people that all engineering is about tradeoffs. People who engineered bridges during Roman Empire had different tradeoffs to consider than people who were building bridges in 20th century. Standing for a thousand years is rarely an ultimate goal when engineering a bridge although it is possible that Romans planned for longer timescales than us. If we decided to build like Romans did, there would likely be very little infrastructure and many structures would simply be impossible to construct.
- lukan 3y ago
  "If we decided to build like Romans did, there would likely be very little infrastructure" Why? The romans build lots of infrastructure. Roads, sewage, irrigation, .. and they used the materials and technics of their time. Can't we really do better today, with all our advanced technology? Or can't we, because everything has to be cheap, cheap, cheap? I mean, the romans used slaves. That is cheap. But we have machines.
  - lotsofpulp 3y ago
    How much population did the Romans build for? How much weight were the Romans subjecting their structures to, and at what acceleration/deceleration? Do you know the movements of the supply and demand curves of the materials required since Roman times? These types of hypotheticals are a waste of time, and only serve to illustrate hubris, as if something as complicated as comparing Roman construction and resources to modern day construction and resources could be possible.
    - lukan 3y ago
      "as if something as complicated as comparing Roman construction and resources to modern day construction and resources could be possible." Well, one can compare the results. Personally I like things that are build solid and can last a 1000 years. But I don't think I said the romans build better. They just had a different intention: long lasting.
      - 3y ago

kwhitefoot 3y ago

> could you call it well-engineered? What is well engineered depends on the goals and the limitations of the state of the art at the time. I would say that a thousand year old bridge might count as well engineered if the goal was a bridge that had a low total lifetime cost.

deleted 3y ago

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