Grade Crossing gate question

[rob_c65]

Just curious. What type of device triggers crossing gates & lights to become active before a train comes through? and how far in advance is it triggered?

I apprecite any ideas.

[CMSTPP]

The tracks are insulated in 4 spots so that when the train crosses over that spot it creates a curcuit and lights the crossings and lowers the gates. Now they have new thing out. They insulate the tracks about half a mile from the crossing. When the train reaches a spot where it is approxiamately 38 seconds from the crossing a computer chip reads the speed and calculates when the train is 38 seconds from the crossing and lowers the gates and lights the crossing up.
James

[rob_c65]

Great. Thanks CMSTPP. Sounds interesting.

[CMSTPP]

No problem. One of those things you learn from fathers.[:D]
James

[nssr9169]

In most cases on modern railroads that is the case as above but on a older R.R. sutch as the NSSR, the tracks have a isolation joint bar about 1/4 of a mile away that is a uncompleated cerket. Once a locomotive or car crosses that joint they compleat the cerket and set the signals off. [C):-)]

[Anonymous]

QUOTE: Originally posted by CMSTPP

The tracks are insulated in 4 spots so that when the train crosses over that spot it creates a curcuit and lights the crossings and lowers the gates. Now they have new thing out. They insulate the tracks about half a mile from the crossing. When the train reaches a spot where it is approxiamately 38 seconds from the crossing a computer chip reads the speed and calculates when the train is 38 seconds from the crossing and lowers the gates and lights the crossing up.
James

Actually, this is partially correct. Most Class 1 railroads use coded track circuits for their signal systems. If insulated joints were used it would interrupt that circuit. So the way it is done, at least at Norfolk Southern, is to use tunable shunts. The equipment in the signal house sends a transmitted pulse on the rail, when the pulse reaches the shunt it knows that their are no trains present. This happens continually until a train passes either of the shunts (one in both directions). When the GCP detects train presence, it then calculates the speed of the train and drops the gates 30 before the train reaches the crossing. FRA mandates 25 seconds. NS requires 30. This is how NS does it, and most major railroads do the same...

[Jack_S]

I saw an interesting thought in the LA Times the other day. When a car encounters a flashing red light at a road intersection it means stop then proceed when safe. When they encounter a flashing red RR crossing light it means stop and stay stopped until the light goes completely out. if they are thinking the way they do for cars, they might look for cross traffic much closer than a train would be.

The suggestion is that this difference is confusing some of the less thoughtful drivers out there. Even a good driver who is preoccupied might misinterpret them. It is being suggested that the grade crossings in the LA Basin should go to a steady red light for crossings to unify the message.

I don't know about this. With the frequency of people running ordinary red lights going up, I wonder if it makes any difference at all. I prefer going to 4 crossing gates at all grade crossings, making it harder to drive around the gate.

Jack

[Anonymous]

QUOTE: Originally posted by Jack_S

I saw an interesting thought in the LA Times the other day. When a car encounters a flashing red light at a road intersection it means stop then proceed when safe. When they encounter a flashing red RR crossing light it means stop and stay stopped until the light goes completely out. if they are thinking the way they do for cars, they might look for cross traffic much closer than a train would be.

The suggestion is that this difference is confusing some of the less thoughtful drivers out there. Even a good driver who is preoccupied might misinterpret them. It is being suggested that the grade crossings in the LA Basin should go to a steady red light for crossings to unify the message.

I don't know about this. With the frequency of people running ordinary red lights going up, I wonder if it makes any difference at all. I prefer going to 4 crossing gates at all grade crossings, making it harder to drive around the gate.

Jack

I agree... That would give us signalmen work for a life time. It will never happen however. The reason is, if someone was to get passed the first set of gates as they were going down, they would be trapped by the gates on the other side..

[CSSHEGEWISCH]

I haven't seen a grade crossing with four gates since my dim and distant youth. The C&WI had manually operated 4-gate crossings at 130th Street (pneumatic control) and at Burnham Avenue (electric control) near my house. At both crossings, the watchman would first lower the gates that stopped the traffic and then would lower the gates on the far side of the tracks. I never saw all four gates being lowered simultaneously.

[nssr9169]

ALSO we just put in a new set of crossing gates ao the railroad i help out on (NSSR) and for a set of new crossing w/ gates it COST OVER 100,000 [V]that is a deffinet deturent to all crssings having gates. Also it depends on how fast and how freqently the trains run over the rails as required by the FRA. I WOULD LOVE to have gates at every crossing because we have had some accidents that runed the BRAND NEW paint and body work of our locomotives and cars!

[ns_gp60]

I read something in a GE locomotive operators manual, that there is a toggle switch in the cab of the units, which work with the crossing so engineers can turn the crossing on and off. Is this true? Also why will the crossing gate go back up if a train is close to the grade crossing but the train stopped, and didn't pass over the crossing?

[Ham549]

OK YOU ALL FORGOT TO MENTION THE "ISLAND" there is another set of inselated rails right at the crossing so it knows when to rase if you knotes when the train is 1/4 mile down the track the lights go on and the gates go down but when the last has rolled past and it is only twenty feet away the gates will rise. so there are eight sets of insolated rails.

[alstom]

geeps- They will go back up when a train stopped in front because if a train stops it'll more than likely sit there for over 6 minutes (a train's limit to blocking a road so I've heard, unless there's some sort of defect). The gates will go back up allowing traffic and then when the train starts they go back down. There are sensors all over the tracks here in Ohio from the crossing to a quarter of a mile. The thing is, you have to be heavy enough to trigger the sensors, so highrailers have to watch for traffic.

Also, that button you speak of, is not real as far as I know. But with the newer modern crossing signals and gates, the engineer will get a remote control to control the gates. I saw this occurence at Peninsula, OH on the Cuyahoga Valley Scenic Railway (who keeps their protection devices way up to date). Hope that helps, geeps.

.....................

[coborn35]

Kale, where did we put new lights?

[Anonymous]

QUOTE: Originally posted by Ham549

OK YOU ALL FORGOT TO MENTION THE "ISLAND" there is another set of inselated rails right at the crossing so it knows when to rase if you knotes when the train is 1/4 mile down the track the lights go on and the gates go down but when the last has rolled past and it is only twenty feet away the gates will rise. so there are eight sets of insolated rails.

Maybe a really old conventinal crossing, but the new crossing will go up if the train is outside the island and hasn't moved for fifteen seconds.