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"...he suggested that unknown developments in the future might make cast iron strong and safe..." Of course that proved true - we call it steel - and if you go

"...he suggested that unknown developments in the future might make cast iron strong and safe..." Of course that proved true - we call it steel - and if you go by the date of Bessemer's patent (after which steel became cheap enough to use on structures), they only had to wait 9 years.

kragen 3y ago
no, steel is not cast iron ductile cast iron does now exist but bessemer didn't invent it
- rdiddly 3y ago
  You should be like the steel, a little less rigid, in your thinking. Obviously steel isn't cast iron, because hey look at that, different names. Also if steel were cast iron, it wouldn't be an improvement on cast iron as I'm saying, it would just be cast iron. On the other hand, it is primarily composed of iron and is literally cast. Finally the person is speaking in 1847. I don't demand that he exactly predict the future. If he predicts there will be improvements to cast iron (the primary material of his time), I say he's right even if he fails to foresee that the resulting iron product, that is cast, is known by another name and ends up making what he knows and we know as cast iron, obsolete for structural use.
  - kragen 3y ago
    [flagged]
    - rdiddly 3y ago
      I went to engineering school and studied this shit my dude. Stress-strain curves, metallurgy, the whole bit. I know what steel is. Your response is weak. I'm making an apt metaphor about the brittleness of your hard insistence on shallow terminology that snaps instead of yielding to the superior force.
  - kragen 3y ago
    bridge girders are not made of cast steel and are not made by casting; they're made by rolling and sometimes welding, processes that are not really applicable to cast iron. even ductile cast iron can't withstand the degree of rolling used to make i-beams without cracking it is true that some castings are now indeed made of steel, but bridge girders are not among them, and the casting steels used today postdate the bessemer process by generations. chrome wasn't used in steel until 01865 (except, to everyone's great surprise three years ago, in medieval persia), nickel until 01889 (you can roll them as much as you want without cracking, and in fact they're dramatically more ductile than actual structural steel alloys like a36, but generally people don't because they're far too expensive and not at all easy to roll) this is not, as you falsely claim, a quibble about nomenclature, in which bridge girders are made of mostly iron and are made by casting but are just not called 'cast iron'. they aren't cast at all as for 'improvements', bessemer's steel was not an improvement over cast iron in every way (it's softer, has a higher thermal coefficient, and can't be practically cast) but in any case brunel did not make the claim you falsely imply he does: > At present cast iron is looked upon, to a certain extent, as a friable, treacherous, and uncertain material; castings of a limited size only can be safely depended upon; wrought iron is considered comparatively trustworthy, and by riveting, or welding, there is no limit to the size of the parts to be used. Yet, who will venture to say, if the direction of improvement is left free, that means may not be found of ensuring sound castings of almost any form, and of twenty or thirty tons weight, and of a perfectly homogeneous mixture of the best metal? Who will say that beams of great size of such a material, either in single pieces or built, may not prove stronger, safer, less exposed to change of texture or to injury from vibration, than wrought-iron, which in large masses cannot be so homogeneous as a fused mass may be made and which when welded is liable to sudden fracture at the welds? (https://ia801404.us.archive.org/3/items/brunel-isambard.-the-life-of-isambad-kingdom-brunel-civil-engineer/Brunel%20Isambard.%20The%20Life%20of%20Isambad%20Kingdom%20Brunel%2C%20Civil%20Engineer.pdf https://ia801404.us.archive.org/3/items/brunel-isambard.-the... p. 192 (224/603), letter of 01848-03-13) this is clearly not at all what happened. i don't fault brunel for failing to predict the future; i fault you for claiming he did you're wrong, you made a mistake, what you said isn't true, it's false, and by continuing to dance around that and play word games instead of admitting it, not to mention flagging my rebuttals so people can't see them, you're leaving traps for people in the future who read this thread to try to understand the historical development of metallurgy and please leave the 'my dude' shit (https://news.ycombinator.com/item?id=35664138 https://news.ycombinator.com/item?id=35664138) on twitter or wherever you picked it up, that kind of bullshit isn't welcome here. likewise the claim to be an authority on a subject because you took a class on it in college. a degree is not a substitute for knowing what you're talking about in fact that is much of brunel's point in these letters

kragen 3y ago

no, steel is not cast iron ductile cast iron does now exist but bessemer didn't invent it

rdiddly 3y ago
You should be like the steel, a little less rigid, in your thinking. Obviously steel isn't cast iron, because hey look at that, different names. Also if steel were cast iron, it wouldn't be an improvement on cast iron as I'm saying, it would just be cast iron. On the other hand, it is primarily composed of iron and is literally cast. Finally the person is speaking in 1847. I don't demand that he exactly predict the future. If he predicts there will be improvements to cast iron (the primary material of his time), I say he's right even if he fails to foresee that the resulting iron product, that is cast, is known by another name and ends up making what he knows and we know as cast iron, obsolete for structural use.
- kragen 3y ago
  [flagged]
  - rdiddly 3y ago
    I went to engineering school and studied this shit my dude. Stress-strain curves, metallurgy, the whole bit. I know what steel is. Your response is weak. I'm making an apt metaphor about the brittleness of your hard insistence on shallow terminology that snaps instead of yielding to the superior force.
- kragen 3y ago
  bridge girders are not made of cast steel and are not made by casting; they're made by rolling and sometimes welding, processes that are not really applicable to cast iron. even ductile cast iron can't withstand the degree of rolling used to make i-beams without cracking it is true that some castings are now indeed made of steel, but bridge girders are not among them, and the casting steels used today postdate the bessemer process by generations. chrome wasn't used in steel until 01865 (except, to everyone's great surprise three years ago, in medieval persia), nickel until 01889 (you can roll them as much as you want without cracking, and in fact they're dramatically more ductile than actual structural steel alloys like a36, but generally people don't because they're far too expensive and not at all easy to roll) this is not, as you falsely claim, a quibble about nomenclature, in which bridge girders are made of mostly iron and are made by casting but are just not called 'cast iron'. they aren't cast at all as for 'improvements', bessemer's steel was not an improvement over cast iron in every way (it's softer, has a higher thermal coefficient, and can't be practically cast) but in any case brunel did not make the claim you falsely imply he does: > At present cast iron is looked upon, to a certain extent, as a friable, treacherous, and uncertain material; castings of a limited size only can be safely depended upon; wrought iron is considered comparatively trustworthy, and by riveting, or welding, there is no limit to the size of the parts to be used. Yet, who will venture to say, if the direction of improvement is left free, that means may not be found of ensuring sound castings of almost any form, and of twenty or thirty tons weight, and of a perfectly homogeneous mixture of the best metal? Who will say that beams of great size of such a material, either in single pieces or built, may not prove stronger, safer, less exposed to change of texture or to injury from vibration, than wrought-iron, which in large masses cannot be so homogeneous as a fused mass may be made and which when welded is liable to sudden fracture at the welds? (https://ia801404.us.archive.org/3/items/brunel-isambard.-the-life-of-isambad-kingdom-brunel-civil-engineer/Brunel%20Isambard.%20The%20Life%20of%20Isambad%20Kingdom%20Brunel%2C%20Civil%20Engineer.pdf https://ia801404.us.archive.org/3/items/brunel-isambard.-the... p. 192 (224/603), letter of 01848-03-13) this is clearly not at all what happened. i don't fault brunel for failing to predict the future; i fault you for claiming he did you're wrong, you made a mistake, what you said isn't true, it's false, and by continuing to dance around that and play word games instead of admitting it, not to mention flagging my rebuttals so people can't see them, you're leaving traps for people in the future who read this thread to try to understand the historical development of metallurgy and please leave the 'my dude' shit (https://news.ycombinator.com/item?id=35664138 https://news.ycombinator.com/item?id=35664138) on twitter or wherever you picked it up, that kind of bullshit isn't welcome here. likewise the claim to be an authority on a subject because you took a class on it in college. a degree is not a substitute for knowing what you're talking about in fact that is much of brunel's point in these letters