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Oops! Getting acquainted with the buffer stops


bikkuri bahn

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This really does not surprise me.  North American public transit and railways operate strictly to the lowest common denominator at best.

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I can't really see anything in that video to mechanically trip the dead man brake.  Did I miss something there?

 

Cheers

 

The_Ghan

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I can't really see anything in that video to mechanically trip the dead man brake.  Did I miss something there?

 

As the line is light rail or an upgraded tram line, I doubt if there is block signalling.

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The white object visible between the rails at the far end of the platform could be a magnet for some type of ATC system at least approaching the terminus even if not continuously block signalled. The train doesn't seem to me to be slowing down though, light rail vehicles usually have quick acting brakes by virtue of their having to operate on line of site or in traffic on street trackage.

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Still, it's nice to see another consist without yellow cabs and doors .....  :cool:

 

Seriously, I also noticed it didn't seem to be slowing down.  Very odd.

 

Cheers

 

The_Ghan

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From a bit of googling, it seems that the system uses a mix of manual and ABS block, and the ABS signals have ATS based on magnets, that can trip the brakes.  There are also some ATS magnets designed to limit maximum speed in areas at risk.  See this set of blog posts for some detail.  According to an official description (PDF) 70% of the system uses ABS, but it's not used where "line of sight operation" is possible. I did see one comment on a news story suggesting there was an ATS magnet at the station entrance, but the commentor also claimed not to know the system very well.  Comments on this site suggest that they don't have ATS magnets at the end of the line, but do have a 20mph limit at the station entrance and one poster estimated the train to be going about 12 mph.

 

It sounds like unless there was a red signal at the end of the track there wouldn't be a "stop" magnet there, and the magnets are all painted yellow and I don't see any evidence of one in the video.  The white dot at the far end could be the speed-based magnet (yellow often looks white in poor video).

 

More interesting, it would appear from various comments and news stories that the agency tried to suppress knowledge of the incident, going as far as having a stand-in PR flack deny there had been one. They claim there was no mechanical failure, and a later article said that the operator "was not in control of the train". Likely there was something odd going on.  It will be interesting to see if an accident report comes out with any detail (does NTSB have jurisdiction over a light rail crash?).

 

One interesting tidbit I didn't know: the ATS magnets are permanent magnets.  It takes an energized electromagnet to cancel out the permanent field for a "clear" indication, so the system is fail-safe in an electrical outage or control system failure.

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