Hey I was kinda thinking what can trip lights and gates I know loco’s can but if the train is coming up backward how do the lights get tripped then. Also when a high rail truck comes up to the crossing can they trip the lights or do they have to wait until traffic is clear until the go and cross. Also I was wondering how far does a loco have to be from a crossing before the gates come down and the lights come on. Oh yeah one more thing when a couple of cars become run aways do the cars have something on them to trip the lights to warn traffic that a run away is coming down the tracks. If anyone has info on this subject can you pass it on my way [:D][:D]
Track circuitry operates crossing protection in most cases. Locomotives and cars will shunt the track circuits initiating the protection a specified distance from the crossing as required by maximum track speed. For the most part, hi-rail vehicles do not shunt track circuits.
Besides, they can stop much faster than a train.
I used a beer bottle cap one time.
Carl T.
[?]How do you do that[?]
James[C):-)]
As BaltACD said, locos and cars shunt the circuits, activating the crossing protection.
The circuits work by looking for a short circuit between the rails. There are many factors involved in determining the proper resistance at which to trip the gates and lights. If the system is too sensitive then road salt residue and a little rain will be enough to bridge the gap. If the sensitivity is too low then the gates may not trip for a small train. It can be a fine line. Modern microprocessors can make adjustments by themselves, but…
I think someone (probably MC) just went over this, but briefly, older crossing circuits had gaps at specified distances (depending on track speed, etc) from the crossing ,and at the crossing itself. When a train “shorted out” the circuit, it activated lights, etc. Gaps nearer the crossing took care of telling the system when the gates could go back up. New systems still use gaps, but often detect the speed of the train as well, allowing a slower train to get a little closer to the crossing before the gates drop, and allowing the gates to go back up if the train stops in the circuit. Older systems required someone to manually “cancel” the gates if a train had to sit in the circuit for some reason.
IIRC, an earlier thread talked about the wheels of high-rail vehicles being insulated, so no, they don’t trip the gates.
As for a runaway car tripping the gates, they probably should. A possible problem might be a car (or cars) running well over track speed, in which case they might be through a crossing before the gates came all the way down. If for some reason they weren’t making good enough contact with the rail (rust, dirt, etc), the cars might not be detected.
Lotus098,
Some friends and I were near a rural crossing.
And was wondering if it would work,so I cracked open a beer,
and found the insulated rail joint.
All I did was bridge the gap in the rail with the cap,
and a couple of sparks later the gates came down,bell ringing,and lights flashing.
It stopped after about 10-20 seconds.
I don’t recommend doing that kind of thing today.
Won $20.00 though [:D]
Carl T.
[:D]Lucky the railroad police did not catch you.[:D]
James[C):-)]
Youre right,that was a long time ago.
Don’t do stuff like that any more.
Carl T.
The newest systems do not required any insulated joints. They still have an island detector but use an AC signal instead of a DC track circuit, the AC signal does not require insulated joints. Different frequencies are used where several grade crossings are close together. Most of the time they do not interfere with each other, however I know of one that is a constant problem. These systems can be overlaid in ABS and CTC territory without extra equipment and wiring to bridge the older insulated joints for the ABS or CTC system. The bottle cap won’t work on the newer systems unless it is wide enough to reach both rails.
i could tell you…but then i would have to kill you…lol
but to keep you from doing something that you shouldnt be doing…im not saying a word…lol
csx engineer
There is another way to “Throw em” but I am not going to say anything either because we think that local kids might want to try and mess up the rush hour in the morning.
Heck, just ask the kids. They can probably fill you in in great detail…
I did that too. course it wasn’t the smartest thing to do because shorting out the Track causes the Dispatcher’s computer to detect it and that it “WILL” cause the Train Dispatcher to take action. The UP calles it a “BK”. So word of wise! Don’t ever do it ever again. I found that out. Of course this is when I was young too.
Allan.
Someone must have found that secret way or had a bottle cap because the other day I was stuck at a crossing and there wasn’t a train anywhere in sight. People eventually started driving around the gates and over the tracks.
LOL! It was probably just the local dispatcher, toying with you from his computer…
Malfunctions do happen from time to time.
As for high rail trucks; some do trigger the gates.
Gate circuits fail safe with the gates down. Would you rather have a train come barreling through with no warning? I’d rather have that inconvenience then getting hit by a train. That would definitely leave a mark!
Just toss a pipe across the rails.
Jumper cables [}:)]