"daestrom" wrote in message
...
[snip]
Big grin!!! The crossing arms are triggered by oncoming trains by
shorting
the two rails together and completing a circuit. You did the same thing
with your steel tape (it isn't very much current, just a ma or two).
I watched a front-end loader clearing snow a few years ago in a nearby
town.
He wanted to cross the road often to dump the snow on the other side, but
traffic was always a problem for him. Well, he was working across a
railroad track that serviced a small factory and had the usual red lights
and crossing arms. When he was ready to cross the road, he lowered the
bucket down to touch the rails. Bingo!, the lights would flash, the arms
would drop and traffic came to a stop. He'd lift the bucket, cross the
road
and dump, and return while the crossing arms were finishing their cycle
and
rising back up. He had learned to 'work the system'. But I don't think
CSX
approves of such chicanery.
When I was a teenager, the local railroad used a much more primitive system:
S1-------------Bars-------------S2
Oncoming train would trip switch S1 (or S2) and the bars would lower.
Leaving train would trip switch S2 (or S1) and the bars would go up.
Taking long walks on the railroad tracks was one of my favorite activities
in the summer, so one day I discovered S1. After I pressed it with my foot,
I knew it was some sort of switch, but didn't know exactly that it was S1,
until walking back I saw a heap of stopped cars at the crossing, the drivers
yelling at the the railroad crossing attendant, who was running for some
strange reason towards the opposite side of where I was coming from.
He was of course going to trip the opposite switch, so that the bars would
go up.
On first thought, a funny connundrum. On second thought, a potentially _very
dangerous_ situation, because, IF, while S1 was tripped, a REAL train came
and tripped S2, you can imagine what would've ensued.
Naughty kid :-)
daestrom
--
Ioannis
http://ioannis.virtualcomposer2000.com/
Eventually, _everything_ is understandable