“Are most crossing gates designed to pick back up if they come down on a vehicle?”
I saw in a video of a similar incident where the gate lifted back up a bit after coming down on a car to allow it to continue through, in this case, it simply rested on the car roof.
The story of this run if anyone wants to read it…
Well, I caught a Buffalo & Pittsburgh inbound coal train this Saturday while I was in town, by chance, as the trains mostly run on Monday and Thursday nights. The time was about 11:45 a.m. Upon hearing the horn, I went on down to the last crossing at the edge of the town of Indiana, PA, to wait for the train (this way I don’t have to put up with the traffic congestion trying to chase it). There, a guy stopped past the crossing sign, and I watched the gate come down on the roof of his car. After several seconds of sitting there, he finally got the idea to continue on through the crossing, with the gate scraping his roof as he continued through (he likely realized he was too close to the crossing when he saw the train and didn’t want the front of his car shaved off).
I followed that train up to Homer City, where I got a bit of a treat-some SW1500 switchers from the plant were there waiting. 2 switchers, #s 44 and 1506, waited for the incoming train, while a third (I didn’t see its number) continued up the hill on the spur to the Homer City Generating Station. The coal train that came in was smaller than usual, between about ½ and ¾ the usual size, with 3 locos leading it.
It came in on the main track, and, after it had made it past the wye, the switchers, on the second track, moved ahead to the switch, and worked its way back to the end of the train, tying on the rear. The
Crossing gates are carefully counter-balanced which explains why they bounce back up slightly after landing on an auto or other object. However, I have never heard of a specific mechanism that would cause them to raise after striking something.
A crossing gate may bounce up slightly if it hits something on the way down, but it will not go back up until the train has cleared the activating section of track.
Refresh my memory - isn’t down the “at rest” position of the gates, their being held up by applied current? Therefore, when the gates are activated, gravity is actually lowering them.
Indeed, the gates’ resting position is down, but I don’t know how they’re setup in regards to current. I’d think that once they’re fully up, some kind of locking mechanism would be in place, so there’d be no need to apply constant current to keep them up.
The are held up electrically. Lose power and they drop. They are designed to fail in the most restricted position. Best left to a signalman (RWM) to better explain the variations and how many dc trip switches are in play. Batteries only last so long…
Depending on who makes the gates determines if gravity and the gate’s moment arm drop the gates (using the mechanical gearing to meter the speed of the dropping arm as a brake) -or- if there is a second gear motor involved to drop the gate with the primary gate-raising system motor in idle.
Adding weights to the counterarm of the gate can be an art due to wind and other factors.
We have one at a local crossing that when it raises, it slams into the bell causing it to make a noise then the whole gate shakes for a moment. Its fun to watch.
I have seen grade crossing gates raise back up when they hit a vehicle crossing the tracks as the gates are being lowered. I don’t know if they have a sensor that detects the impact, and causes the gates to raise.