4 ms·

I'd guess that the amount of momentum in a quickly moving train makes any changes take a lot longer to take place and mistakes harder to address in time. You do

by mentat 11y ago

I'd guess that the amount of momentum in a quickly moving train makes any changes take a lot longer to take place and mistakes harder to address in time. You don't just stamp the brakes to stop or push the accelerator to speed up. The cycle time on system changes requires "tending".

rconti 11y ago
Others also pointed out trains are big and heavy, which I thought of more in terms of an advantage (doesn't exactly speed up all that quickly) or neutral in terms of impact on the conductor (if it crashes, yes, it's a big deal, but assuming it doesn't, it's not). I hadn't thought about it in terms of cycle time and 'tending' as you mention. You're right that having to plan things ahead, and watching the consequences of your earlier actions unfold slowly can be quite stressful. I imagine it also demands much more in terms of multi-tasking because you can't just respond to an immediate need, you need to keep more 'balls in the air' at a given point in time because of how slowly the controls respond. Excellent point, thank you.
- Symbiote 11y ago
  I think planning ahead is the main thing, resulting from the huge momentum of the train and the low friction with the track. It's essential to stop in the correct places, but it's also necessary to keep accelerations smooth (we don't want all the wagons bumping together, or slipping wheels), including up and downhill. Driving must also be efficient, and with good planning it's easily possible to coast many miles on a slight gradient. (Did everyone just get off the train at the stadium? Then the braking distance will change. Except it's raining now, so it's longer.) Acknowledge every signal, and run to time — being early means being stopped, which is wasteful (and annoying for passengers, if this is a passenger train), being late means delaying other trains. -- I read some of the accident reports from the British RAIB, since they're often interesting. It's hardly ever one failure, even for something that seems straightforward. Some of the reports show charts of management structures, since many problems come down to organizational mismanagement — the safety equipment exists, but perhaps wasn't maintained, or a fault wasn't repaired soon enough. By doing 50-page investigations into accidents (or near-misses) with no injuries, hopefully serious accidents will be avoided — and it seems to work, I think it's the safest railway network in the world. List of all publications: https://www.gov.uk/government/collections/catalogue-of-investigation-reports-and-bulletins https://www.gov.uk/government/collections/catalogue-of-inves... Recent example (PDF) https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/491086/R012016_160111_Washwood_Heath.pdf https://www.gov.uk/government/uploads/system/uploads/attachm... — a 49 page report for an accident with no injuries.

by mentat 11y ago

rconti 11y ago

Others also pointed out trains are big and heavy, which I thought of more in terms of an advantage (doesn't exactly speed up all that quickly) or neutral in terms of impact on the conductor (if it crashes, yes, it's a big deal, but assuming it doesn't, it's not). I hadn't thought about it in terms of cycle time and 'tending' as you mention. You're right that having to plan things ahead, and watching the consequences of your earlier actions unfold slowly can be quite stressful. I imagine it also demands much more in terms of multi-tasking because you can't just respond to an immediate need, you need to keep more 'balls in the air' at a given point in time because of how slowly the controls respond. Excellent point, thank you.

Symbiote 11y ago
I think planning ahead is the main thing, resulting from the huge momentum of the train and the low friction with the track. It's essential to stop in the correct places, but it's also necessary to keep accelerations smooth (we don't want all the wagons bumping together, or slipping wheels), including up and downhill. Driving must also be efficient, and with good planning it's easily possible to coast many miles on a slight gradient. (Did everyone just get off the train at the stadium? Then the braking distance will change. Except it's raining now, so it's longer.) Acknowledge every signal, and run to time — being early means being stopped, which is wasteful (and annoying for passengers, if this is a passenger train), being late means delaying other trains. -- I read some of the accident reports from the British RAIB, since they're often interesting. It's hardly ever one failure, even for something that seems straightforward. Some of the reports show charts of management structures, since many problems come down to organizational mismanagement — the safety equipment exists, but perhaps wasn't maintained, or a fault wasn't repaired soon enough. By doing 50-page investigations into accidents (or near-misses) with no injuries, hopefully serious accidents will be avoided — and it seems to work, I think it's the safest railway network in the world. List of all publications: https://www.gov.uk/government/collections/catalogue-of-investigation-reports-and-bulletins https://www.gov.uk/government/collections/catalogue-of-inves... Recent example (PDF) https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/491086/R012016_160111_Washwood_Heath.pdf https://www.gov.uk/government/uploads/system/uploads/attachm... — a 49 page report for an accident with no injuries.