jeffhergert charlie hebdo You and others feel a need to disparage these victims. Why? In the US, we used to have four-quadrant gated crossings same as Europe. I can remember them. They work. Then to save money, two quadrant systems became the rule. Big mistake. Some Quiet Zones have 4 quadrant gates. IA Hwy 17 east of Boone has 4 quadrant gates, but I don't know why. I do believe they have fallen somewhat out of favor for the reason mentioned. There have been motorists trapped and then struck by the train. Now, the gates are hinged and you can drive through them in such instances, but most people don't know that. The gates at the IA 17 crossing don't all come down at once. First, the gates on the entrance side of the crossing come down. When they are about halfway down, the exit side gates come down. That should lessen the chance of someone getting trapped. Jeff
charlie hebdo You and others feel a need to disparage these victims. Why? In the US, we used to have four-quadrant gated crossings same as Europe. I can remember them. They work. Then to save money, two quadrant systems became the rule. Big mistake.
You and others feel a need to disparage these victims. Why?
In the US, we used to have four-quadrant gated crossings same as Europe. I can remember them. They work. Then to save money, two quadrant systems became the rule. Big mistake.
Some Quiet Zones have 4 quadrant gates. IA Hwy 17 east of Boone has 4 quadrant gates, but I don't know why.
I do believe they have fallen somewhat out of favor for the reason mentioned. There have been motorists trapped and then struck by the train. Now, the gates are hinged and you can drive through them in such instances, but most people don't know that.
The gates at the IA 17 crossing don't all come down at once. First, the gates on the entrance side of the crossing come down. When they are about halfway down, the exit side gates come down. That should lessen the chance of someone getting trapped.
Jeff
Those that get 'trapped' have only themselves to blame! Floor it and scrape the paint on the vehicle or break the gate arm. GTF off the crossing.
Never too old to have a happy childhood!
I have often thought that the second gate should have a clear sign saying something to the effect, "Breakaway gate, if trapped drive through it".
matthewsaggieI have often thought that the second gate should have a clear sign saying something to the effect, "Breakaway gate, if trapped drive through it".
Non-punitive alert if the hinge is actuated. Is there any current notification with these hinged gates, or is their action just 'passive'?
Note that the hinge would need to lock at any time the gate is being raised or lowered (a simple sliding gravity lock backed by a spring might work) to prevent wind deflection. The amount of force to 'open the hinge' might need to be more than a pedestrian could exert...
An advantage of hinged over breakaway is that the gate protection remains effective for subsequent crossings without required MOW attention.
Seems like a sensible, modest way to reduce fatalities.
jeffhergert The gates at the IA 17 crossing don't all come down at once. First, the gates on the entrance side of the crossing come down. When they are about halfway down, the exit side gates come down. That should lessen the chance of someone getting trapped.
Early installations of automatic four-quad gates used this approach - know as "exit gate timing" - exclusively. It leads to its own problems. People who want to drive around the gates sometimes are induced to do so in a recklessly fast manner in order to beat the exit gate.
For well over a decade now, the preferred approach has been to use a vehicle detection system to see if any vehicles are in the crossing when the signals activate. The entrance gates descend at the normal time, but the exist gates stay up until the crossing is clear. In the "normal" case, where there aren't any cars on the crossing, both the entrance gates and the exit gates descend simultaneously.
Traditionally, this vehicle detection has been accomplished using inductor loops in the pavement. Some newer installations use radar.
The interesting thing about exit gates is that, unlike most railroad signaling equipment, there isn't really a safe failure mode. If they descend when they shouldn't, they could trap a vehicle. If they don't descend when they should, then cars might drive around the entrance gates.
When the vehicle detection system fails, the most common behavior is to fall back to exit gate timing. In at least one state, the regulators do not allow exit gate timing at all, so a failure in the VDS will prevent the exit gates from descending at all.
Looking at IA-17 in Boone and reading the FRA accident history, I would guess that the 4-quad gates were installed to stop people making left-hand turns at the nearby intersections from accidentally driving past the tip of the gate and running into the side of a train. (There were three "train struck by vehicle" accidents between 1996-2000.)
Dan
Overmod matthewsaggie I have often thought that the second gate should have a clear sign saying something to the effect, "Breakaway gate, if trapped drive through it". Better yet, perhaps, some variant of 'hinged gate, no fine if you drive through'. The back of the gate could be brightly painted with instructions where to 'contact' it with a vehicle to get far enough off the tracks. Non-punitive alert if the hinge is actuated. Is there any current notification with these hinged gates, or is their action just 'passive'? Note that the hinge would need to lock at any time the gate is being raised or lowered (a simple sliding gravity lock backed by a spring might work) to prevent wind deflection. The amount of force to 'open the hinge' might need to be more than a pedestrian could exert... An advantage of hinged over breakaway is that the gate protection remains effective for subsequent crossings without required MOW attention.
matthewsaggie I have often thought that the second gate should have a clear sign saying something to the effect, "Breakaway gate, if trapped drive through it".
Better yet, perhaps, some variant of 'hinged gate, no fine if you drive through'. The back of the gate could be brightly painted with instructions where to 'contact' it with a vehicle to get far enough off the tracks.
I think all modern gates are hinged. I know all of the crossing gates along our main line are hinged. A month or so back when we were experiencing a day of very high winds, we had many crossing notices of crossing devices not working properly. It was because of the winds on the gates. Some had been blown off center that they were hung up on the various items attached to the signal pole, such as the large "wig/wag" flashing lights and couldn't drop. One gate was blown off center when it was down enough that it fouled the tracks and a train broke it off. I came close a couple of times to breaking one off myself.
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