Eastern Railroad Discussion > A question needing an answer

There's a crossing nearby, (on the Lurgan Branch near Harrisburg, Pa) where a siding begins a couple hundred feet down the track. Trains often idle near the crossing while waiting for a meet to occur. It appears as soon as the dispatcher says they're clear to move, the crossing gates and signals are activated and the train proceeds. My question is who activates the crossing signals? The engineer or the dispatcher? And what keeps the crossing signals from activating while a train is idling 100 feet up the tracks?

Most modern grade crossing signals have motion detection.

rfprr

Normally grade crossing signals and gates are activated by a motion sensor system. It's part of the track circuitry and involves a complex (to me) arrangement of various frequencies in the rails, and track circuits. So, crossing activation is totally automated, and independent of any action on the dispatcher's part, other than clearing the train for movement. The engineer throttles up to inch the train into motion and the track circuitry does the rest. Also, this is why a stopped train that remains stopped doesn't activate a grade crossing.

Any corrections or additions are welcome.

I have noticed a white painted tie near the crossings, maybe a indication to the engineer where to stop

Ed Stewart
Jacksonville, FL

I think the white painted tie indicates drainage under the track. At least that's how it is up on the CSX in the northeast.

calsubd Wrote:
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> I have noticed a white painted tie near the
> crossings, maybe a indication to the engineer
> where to stop

Posted from iPhone

I seen a couple of crossings east of Toledo around Vickers that would activate when the dispatcher lines up trains, like on NS side, the next crossing east of Vickers would activate anytime dispatch lined up an eastbound, or Pickle road on the ex Toledo terminal used to come on when the dispatcher lined up a southbound , not sure if they still do since the signal upgrade

The train doesn't have to stop at any particular spot. As long as the train stops and remains stopped, the crossing signals will de-activate (assuming they were activated by the train's approach).

As stated above, corrections welcomed.

Most crossings today are motion sensor. There are crossings in my area that activate when the dispatcher lights a train up, and there are quite a few that the engineer can activate by toning in a code via radio.

I seen many times when a train comes up near a crossing and the lights or gates operate. The train stops and after a few seconds the signals return to normal. Then, when the train begins moving again, and usually only two or three feet at the most, the signals operate again.

Regarding the white ties, I was under the impression that they were there to indicate the limits of a track to prevent fouling of the adjacent track when approaching a turnout. The attached picture is O'Bannon Yard (Ford Truck plant in Louisville, Ky.) I've circled several location where a tie is white. I don't know, just what I thought to be correct. Corrections are welcomed. After all, that's why allot of us ask questions here on TO.com. WE DON"T KNOW!

John

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Usually ties painted white are for culverts crossing under the tracks. I have seen green & yellow ties painted in yards to show the foul points of the tracks. Those pictured would certainly be foul points. So both answers above are correct. Just someone in this yard picked white I guess.