Wow, what an amazing story. Fascinating from an engineering perspective. Quoting a few of my favorite bits:
>Mark began by taking a vertical slice of, say, Chartres and replicating it in a special kind of plastic. He’d then hang fishing weights from various points on the plastic replica, like ornaments on a Christmas tree, to simulate the actual external forces acting upon various parts of the cathedral. There was the direct load of the overhead stone, of course, but also the winds. (To estimate the winds in the 12th century, he found anemometer readings in rural France going back a century. Not perfect, but good enough.) He placed his fully loaded plastic model in an oven, where it was subjected not just to heat but also light. Warmed, the plastic model revealed its stresses, sort of like the way an MRI reveals damage to soft human tissue.
>“The very words ‘statistical analysis’ seem foreign to many in rock engineering. Engineers are trained to see the world in terms of load and deformation, where failure is simply a matter of stress exceeding strength. Statistics are generally given short shrift in engineering curriculums, and so the entire language of statistics is unfamiliar. Yet statistics are the tools that science has developed to deal with uncertainty and probability, which are both at the heart of mining ground control.”
>Real-life American workers were different from his mental model of them. “I had thought if they only knew what I thought, they’d see things how I do,” he said. That idea now struck him as so obviously nuts that he didn’t bother to let them know what he thought. His fellow coal miners were less concerned with his ideas about the economy and their rightful place in it than in simply making a living. Their morale, at that moment, was actually sky-high. “Coal was booming,” said Chris. “We were going to save the world. Thank god we have all this coal so we’re not reliant on Arab oil. People felt good about themselves.”
>“A mine is unlike any man-made structure,” said Chris. “It’s not a designed environment. Most of the material the structure is made from is kind of unknown. With rock you don’t know what the engineering properties are — what the loads are. You have a problem that is really not an engineering problem, but people were insisting on using an engineering mindset to solve it.”
>Again, he found work done by others and repurposed it for his uses. Back in the 1940s, geologists working for the Agriculture Department in national forests created a crude method for work crews to determine if some rock would work as a road: whacking it with a ball-peen hammer. Oddly, it didn’t matter how hard you whacked it. There were just a handful of ways the rock might react, and its specific reaction revealed its strength. Chris started whacking mine roofs with ball-peen hammers. “It’s not precise,” he said, “but it does get you in the ballpark.”
>Mark began by taking a vertical slice of, say, Chartres and replicating it in a special kind of plastic. He’d then hang fishing weights from various points on the plastic replica, like ornaments on a Christmas tree, to simulate the actual external forces acting upon various parts of the cathedral. There was the direct load of the overhead stone, of course, but also the winds. (To estimate the winds in the 12th century, he found anemometer readings in rural France going back a century. Not perfect, but good enough.) He placed his fully loaded plastic model in an oven, where it was subjected not just to heat but also light. Warmed, the plastic model revealed its stresses, sort of like the way an MRI reveals damage to soft human tissue.
>“The very words ‘statistical analysis’ seem foreign to many in rock engineering. Engineers are trained to see the world in terms of load and deformation, where failure is simply a matter of stress exceeding strength. Statistics are generally given short shrift in engineering curriculums, and so the entire language of statistics is unfamiliar. Yet statistics are the tools that science has developed to deal with uncertainty and probability, which are both at the heart of mining ground control.”
>Real-life American workers were different from his mental model of them. “I had thought if they only knew what I thought, they’d see things how I do,” he said. That idea now struck him as so obviously nuts that he didn’t bother to let them know what he thought. His fellow coal miners were less concerned with his ideas about the economy and their rightful place in it than in simply making a living. Their morale, at that moment, was actually sky-high. “Coal was booming,” said Chris. “We were going to save the world. Thank god we have all this coal so we’re not reliant on Arab oil. People felt good about themselves.”
>“A mine is unlike any man-made structure,” said Chris. “It’s not a designed environment. Most of the material the structure is made from is kind of unknown. With rock you don’t know what the engineering properties are — what the loads are. You have a problem that is really not an engineering problem, but people were insisting on using an engineering mindset to solve it.”
>Again, he found work done by others and repurposed it for his uses. Back in the 1940s, geologists working for the Agriculture Department in national forests created a crude method for work crews to determine if some rock would work as a road: whacking it with a ball-peen hammer. Oddly, it didn’t matter how hard you whacked it. There were just a handful of ways the rock might react, and its specific reaction revealed its strength. Chris started whacking mine roofs with ball-peen hammers. “It’s not precise,” he said, “but it does get you in the ballpark.”