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I don't understand why there's a button for that. In the UK the trains would be "Cautioned through" this section. "Caution" here being a term of art for an inst

I don't understand why there's a button for that. In the UK the trains would be "Cautioned through" this section. "Caution" here being a term of art for an instruction for drivers to operate a train by hand at a speed where they can reasonably brake the train short of any obstacle - this can mean very, very, slowly if you're on a sharply curved or foggy section. I understand the UK is weird because of route knowledge [a German train driver can expect to just operate a train to anywhere in Germany, a British train driver needs to be intimately familiar with any track section to be used for their journey, as a result the signals in the UK don't need to tell you e.g. "Go 50" but instead "The signal after next is red" because the driver knows "that's the signal in New Town, it's uphill from here, so I can do about 50"] But it seems like caution would be possible everywhere.

nic547 2y ago
Route knowledge exists in Germany, it's called "Streckenkunde" and under normal circumstances drivers in germany can't just drive anywhere. I think it's a fairly common thing in europe, Switzerland and Austria also require aquisition of route knowledge.
- tialaramex 2y ago
  Ooh, I did not know that.
red_admiral 2y ago
A lot of people wondered at the time why that button exists - I think the answer is something like "it is only pressed by competent and trained professionals after they have followed a number of protocols to make absolutely sure there is nothing on the single line" (at this point I can hear safety and human factors experts crying out in pain). Maybe that protocol involves scratching your head and wondering if you can remember recently signalling or accepting a train in the other direction! There was a time when, whatever buttons or levers you had, nothing goes on the single line until someone has found the token. You wonder whether a digital "TOKEN OUT" light would be possible on the signallers panel. Driving at caution is great when you're looking out for a possible broken rail, tree on the line, or a huge maintenance trolley left behind by an incompetent overnight repair team (this happened not too far back), or when you're expecting a train ahead stopped or going in the same direction. In the German case, you have a train going from A to B correctly going at linespeed under greens, so even if you signal the train from B to A into the section at caution, you're going to have a bad day. Perhaps lower impact velocity/energy, but I still wouldn't fancy the probability of survival under those circumstances. Switzerland does caution if you're instructed to pass a red light, I think Austria does too?

nic547 2y ago

Route knowledge exists in Germany, it's called "Streckenkunde" and under normal circumstances drivers in germany can't just drive anywhere. I think it's a fairly common thing in europe, Switzerland and Austria also require aquisition of route knowledge.

tialaramex 2y ago
Ooh, I did not know that.

red_admiral 2y ago

A lot of people wondered at the time why that button exists - I think the answer is something like "it is only pressed by competent and trained professionals after they have followed a number of protocols to make absolutely sure there is nothing on the single line" (at this point I can hear safety and human factors experts crying out in pain). Maybe that protocol involves scratching your head and wondering if you can remember recently signalling or accepting a train in the other direction! There was a time when, whatever buttons or levers you had, nothing goes on the single line until someone has found the token. You wonder whether a digital "TOKEN OUT" light would be possible on the signallers panel. Driving at caution is great when you're looking out for a possible broken rail, tree on the line, or a huge maintenance trolley left behind by an incompetent overnight repair team (this happened not too far back), or when you're expecting a train ahead stopped or going in the same direction. In the German case, you have a train going from A to B correctly going at linespeed under greens, so even if you signal the train from B to A into the section at caution, you're going to have a bad day. Perhaps lower impact velocity/energy, but I still wouldn't fancy the probability of survival under those circumstances. Switzerland does caution if you're instructed to pass a red light, I think Austria does too?