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In Mexico City, crossing signalamps both lit together!
Posted: Sun Nov 15, 2009 2:18 pm
by Robert_Gift
The crossing signal operator turned on a switch hanging down from the eve of this little crossing signal shack. (Cement block building)
I recall the wires were exposed to the elements where they attached to the switch. (I had no camera.)
When the train approached, he flipped the switch.
Both lights on each signal illuminated simultaneously, alternating between signals!
(o)=(o) (o)=(o)
(o)=(o) (o)=(o)
A green Volkswagon cab crossed just in front of the locomotive, causing the engineer to yell at the driver.
After the locomotive passed, the crossing signal operator switched off the signals!
Re: In Mexico City, crossing signals both lit together!
Posted: Sun Nov 15, 2009 2:19 pm
by Smjh1979
I was looking at Street View a while back in Mexico City. I didn't see that, although there sure was a lot to see.
One thing I found very interesting is the very high amount of Safetran Hybrids down there.
Re: In Mexico City, crossing signals both lit together!
Posted: Sun Nov 15, 2009 2:31 pm
by Robert_Gift
Smjh1979 wrote:I was looking at Street View a while back in Mexico City. I didn't see that, although there sure was a lot to see.
One thing I found very interesting is the very high amount of Safetran Hybrids down there.
I believe the crossing was at the north end of a railroad station not far from the pyramid bank building. There is a carillon in an opening near the top of the building.
The building apparently was closed because of structural concerns after of the Mexico City earthquake.
I'll look for it.
Re: In Mexico City, crossing signals both lit together!
Posted: Fri Nov 20, 2009 5:56 pm
by Robert_Gift
Robert_Gift wrote:Smjh1979 wrote:I was looking at Street View a while back in Mexico City. I didn't see that, although there sure was a lot to see.
One thing I found very interesting is the very high amount of Safetran Hybrids down there.
I believe the crossing was at the north end of a railroad station not far from the pyramid bank building. There is a carillon in an opening near the top of the building.
The building apparently was closed because of structural concerns after of the Mexico City earthquake.
I'll look for it.
What was funny wa that the crossing guard turned off the signals as soon as the locomotive passed.
They remained off while the rest of the train passed.
It appears that that railroad station has been closed.
Re: In Mexico City, crossing signalamps both lit together!
Posted: Fri Nov 20, 2009 9:34 pm
by cabman701
I saw that happen once on a crossing here in town... it was a median signal and the lights flashed together instead of alternating. I guess it was a malfunction, either that or the maintaineer made a wiring mistake. The rest of the signals at the crossing functioned normally.
I was rather young then and never saw that crossing activated again, so I don't know how long that signal was like that. Those tracks have long since been removed.
Re: In Mexico City, crossing signalamps both lit together!
Posted: Fri Nov 20, 2009 10:56 pm
by Robert_Gift
cabman701 wrote:I saw that happen once on a crossing here in town... it was a median signal and the lights flashed together instead of alternating. I guess it was a malfunction, either that or the maintaineer made a wiring mistake. The rest of the signals at the crossing functioned normally.
I was rather young then and never saw that crossing activated again, so I don't know how long that signal was like that. Those tracks have long since been removed.
Since the flasher relay is a see-saw type relay, I do not see how it could be a malfunction.
Likely a wiring error.
I suspect what the Mexicans did was to save wire.
Two wires to each signal instead of three which would be required for alternating lights.
The wire used to operate the signals was hanging from the eve. The switch dangling on the end of the wire.
Why turn off before the rest of the train has passed?
Save electricity? Save bulb filament wear?
So he can sit down and not have to get up and turn it off after the train has cleared?
Re: In Mexico City, crossing signalamps both lit together!
Posted: Sat Nov 21, 2009 1:42 pm
by cabman701
Robert_Gift wrote:Why turn off before the rest of the train has passed?
Save electricity? Save bulb filament wear?
So he can sit down and not have to get up and turn it off after the train has cleared?
In all honesty, once the train has completely entered the crossing... the potential for an accident has greatly reduced. Except for someone not realizing there was a train there and smacking into the side of it.
However, it would be the same thing as a non-signalized crossing (crossbucks only)... or even a crossing being flagged. The flagger is only present while the train is entering... he does not stand there the entire time the train is occupying the crossing.
Re: In Mexico City, crossing signalamps both lit together!
Posted: Sat Nov 21, 2009 8:48 pm
by Robert_Gift
cabman701 wrote:Robert_Gift wrote:Why turn off before the rest of the train has passed?
Save electricity? Save bulb filament wear?
So he can sit down and not have to get up and turn it off after the train has cleared?
In all honesty, once the train has completely entered the crossing... the potential for an accident has greatly reduced. Except for someone not realizing there was a train there and smacking into the side of it.
However, it would be the same thing as a non-signalized crossing (crossbucks only)... or even a crossing being flagged. The flagger is only present while the train is entering... he does not stand there the entire time the train is occupying the crossing.
Yes. I agree. Am not faulting the crossinguard.
Just revealing their practicallity.
I am surprised that do not do the same in China at human-activated crossings.
In China, they have a metal accordian type of barrier which rolls on little flanges wheels pulled by a motor.
I was surprised they did not start the barried back to its parked position just the end of the train neared.
Re: In Mexico City, crossing signals both lit together!
Posted: Sun Nov 22, 2009 12:35 am
by SirKrunch
Smjh1979 wrote:I was looking at Street View a while back in Mexico City. I didn't see that, although there sure was a lot to see.
One thing I found very interesting is the very high amount of Safetran Hybrids down there.
It also looks like they've been busy adding gates to a lot of crossings as well. I found lots and lots of crossings that when you would approach in one direction there were only light signals... but when you approached from a different viewpoint that gates had been added to the setups.
The cantilevers they use are certainly interesting looking... and how the hybrid bells are mounted above the lightheads.
Re: In Mexico City, crossing signals both lit together!
Posted: Sun Nov 22, 2009 7:37 am
by Robert_Gift
SirKrunch wrote:Smjh1979 wrote:I was looking at Street View a while back in Mexico City. I didn't see that, although there sure was a lot to see.
One thing I found very interesting is the very high amount of Safetran Hybrids down there.
It also looks like they've been busy adding gates to a lot of crossings as well. I found lots and lots of crossings that when you would approach in one direction there were only light signals... but when you approached from a different viewpoint that gates had been added to the setups.
The cantilevers they use are certainly interesting looking... and how the hybrid bells are mounted above the lightheads.
Please include links here.
I can imagine their installing gates.
Mexican drivers, especially the little green Volkswagen cabbies, are notorious from sneaking through crossings right in front of trains.
On moron successfully crossed ahead of a train and was hit and killed by another train behind the train he saw.
Guess the Darwin Award winner never considered that possibility.