5 ms·

What's so complex about this situation? I see no problem with mandating a maximum train length.

xpe 4y ago
Are you asking what is 'so complex' about public policy, safety, and economics? Even if this is only about maximum train length, which it isn't, the underlying dynamics, as they are perceived by and affect all the stakeholders, are complex. This is what I mean by complex systems: https://en.m.wikipedia.org/wiki/Complex_system https://en.m.wikipedia.org/wiki/Complex_system Is this what you mean?
xpe 4y ago
Imagine that you were a regulator, such as a member of the National Transportation Safety Board [1]. Put yourself in that position. How would you go about deciding the appropriate regulation? Of course that is not the only stakeholder in the situation. Now for each key stakeholder, including railroad companies, railroad employees, shipping companies, the purchasing public, and landowners near tracks, what would be your professional opinion on the correct outcome? It is pretty clear that what you see depends on where you sit. Now step back even further and imagine you are an omniscient being that can truly comprehend all of the above perspectives. How would you go about deciding the correct outcome? It will depend on your notion of good and fairness. I think for many definitions of good, you'll find that considerable analysis is involved. [1] https://en.m.wikipedia.org/wiki/National_Transportation_Safety_Board https://en.m.wikipedia.org/wiki/National_Transportation_Safe...
- Invictus0 4y ago
  It feels like you're not commenting in good faith but I'll respond in good faith anyway. As a mechanical engineer, my professional opinion is that trains should not be derailing, period. The trains should be allowed to be as long as possible so that they can safely not derail, and perhaps also not dramatically interrupt traffic in towns. It's hardly a question of "should we ensure that trains do not derail": the answer is unambiguously yes, it is not acceptable for them to derail. I accept that asking "what is the appropriate maximum length for a train" might require some deeper thought, but the article is very clearly stating that the problem is that trains are too long and are derailing, not whatever vague "complexity" you keep going on about.
  - xpe 4y ago
    > not whatever vague "complexity" you keep going on about Hopefully you can see (in retrospect, at least) that this language is not going to build goodwill or help understanding. Some people dismiss complexity theory without giving it a chance.
  - throwawayboise 4y ago
    But it's a matter of probabilities. It's not like a train will derail if it's over some length, and won't derail if it's shorter. A 10-car train can derail, it's just less likely at least for causes that are related to train length. There is no regulation that will prevent all derailments with 100% effectiveness.
    - Invictus0 4y ago
      That's true, but there are also engineering principles at play unrelated to probability. If I squeeze a piece of hard spaghetti on it's ends, would it be easier to break a 20cm piece of spaghetti or a 1cm piece of spaghetti? 20cm, obviously, and that same principle applies with trains. Longer trains are harder to stop, harder to control, less robust to disturbances. Likewise, if I squeeze a piece of soft spaghetti on its ends, it's harder to predict how it will bend if it's really long than if it's really short. You won't see a 1cm piece of spaghetti contort itself into loops, but a 20cm piece certainly will.
      - xpe 4y ago
        The spaghetti metaphor tells part of the story, though I’ve never seen spaghetti somewhat coupled (constrained) to some kind of path (analogous to a track). > Longer trains are harder to stop, harder to control, less robust to disturbances. All other things equal, this seems plausible, but I’m no expert on trains. So if I studied it, I would likely agree in most cases. However, I do wonder if longer trains, being more massive, do offer some benefits in some cases. Perhaps a disturbance affecting only one car would have less effect because the other cars have more inertia and resist change. This of course relates the question of the design criteria. Clearly trains should be designed with a cost benefit analysis such that more common disturbances can be handled. What kinds of disturbances can and should be planned for?

xpe 4y ago

Are you asking what is 'so complex' about public policy, safety, and economics? Even if this is only about maximum train length, which it isn't, the underlying dynamics, as they are perceived by and affect all the stakeholders, are complex. This is what I mean by complex systems: https://en.m.wikipedia.org/wiki/Complex_system https://en.m.wikipedia.org/wiki/Complex_system Is this what you mean?

xpe 4y ago

Imagine that you were a regulator, such as a member of the National Transportation Safety Board [1]. Put yourself in that position. How would you go about deciding the appropriate regulation? Of course that is not the only stakeholder in the situation. Now for each key stakeholder, including railroad companies, railroad employees, shipping companies, the purchasing public, and landowners near tracks, what would be your professional opinion on the correct outcome? It is pretty clear that what you see depends on where you sit. Now step back even further and imagine you are an omniscient being that can truly comprehend all of the above perspectives. How would you go about deciding the correct outcome? It will depend on your notion of good and fairness. I think for many definitions of good, you'll find that considerable analysis is involved. [1] https://en.m.wikipedia.org/wiki/National_Transportation_Safety_Board https://en.m.wikipedia.org/wiki/National_Transportation_Safe...

Invictus0 4y ago
It feels like you're not commenting in good faith but I'll respond in good faith anyway. As a mechanical engineer, my professional opinion is that trains should not be derailing, period. The trains should be allowed to be as long as possible so that they can safely not derail, and perhaps also not dramatically interrupt traffic in towns. It's hardly a question of "should we ensure that trains do not derail": the answer is unambiguously yes, it is not acceptable for them to derail. I accept that asking "what is the appropriate maximum length for a train" might require some deeper thought, but the article is very clearly stating that the problem is that trains are too long and are derailing, not whatever vague "complexity" you keep going on about.
- xpe 4y ago
  > not whatever vague "complexity" you keep going on about Hopefully you can see (in retrospect, at least) that this language is not going to build goodwill or help understanding. Some people dismiss complexity theory without giving it a chance.
- throwawayboise 4y ago
  But it's a matter of probabilities. It's not like a train will derail if it's over some length, and won't derail if it's shorter. A 10-car train can derail, it's just less likely at least for causes that are related to train length. There is no regulation that will prevent all derailments with 100% effectiveness.
  - Invictus0 4y ago
    That's true, but there are also engineering principles at play unrelated to probability. If I squeeze a piece of hard spaghetti on it's ends, would it be easier to break a 20cm piece of spaghetti or a 1cm piece of spaghetti? 20cm, obviously, and that same principle applies with trains. Longer trains are harder to stop, harder to control, less robust to disturbances. Likewise, if I squeeze a piece of soft spaghetti on its ends, it's harder to predict how it will bend if it's really long than if it's really short. You won't see a 1cm piece of spaghetti contort itself into loops, but a 20cm piece certainly will.
    - xpe 4y ago
      The spaghetti metaphor tells part of the story, though I’ve never seen spaghetti somewhat coupled (constrained) to some kind of path (analogous to a track). > Longer trains are harder to stop, harder to control, less robust to disturbances. All other things equal, this seems plausible, but I’m no expert on trains. So if I studied it, I would likely agree in most cases. However, I do wonder if longer trains, being more massive, do offer some benefits in some cases. Perhaps a disturbance affecting only one car would have less effect because the other cars have more inertia and resist change. This of course relates the question of the design criteria. Clearly trains should be designed with a cost benefit analysis such that more common disturbances can be handled. What kinds of disturbances can and should be planned for?