Western Railroad Discussion > Crossing gates - how far in advance should they go down

Earlier today I was stopped for an Surfliner. The gates seemed slow in coming down as the train accelerated after a stop. The train wasn't moving fast but the last gate (a new quad installation) came down just as the train entered the crossing. Is there some sort of a standard or industry practice that would call for the gates to be down in the stop position two, three, or perhaps five seconds prior to the locomotive entering the intersection?

john1082 Wrote:
-------------------------------------------------------
> Earlier today I was stopped for an Surfliner. The
> gates seemed slow in coming down as the train
> accelerated after a stop. The train wasn't moving
> fast but the last gate (a new quad installation)
> came down just as the train entered the crossing.
> Is there some sort of a standard or industry
> practice that would call for the gates to be down
> in the stop position two, three, or perhaps five
> seconds prior to the locomotive entering the
> intersection?

Let's begin with the basics: 1) The FRA requires a minimum 20 seconds warning time, beginning from when the lights start flashing to when a train enters the crossing. However, some railroads, such as BNSF, require a minimum 30-second warning time at all mainline crossings.

2 Entrance gates are typically on a 3-second slow-release relay, counting from when the crossing lights activate, sometimes up to 10 seconds if the street is particularly busy.

3) Minimum time for gates to descend is 10 seconds, maximum is 15 seconds.

That being stated, the gate you are referring to could have been an exit gate for vehicle traffic leaving the crossing. Exit gates will descend as soon as a train enters the island, if they have not already descended via the control from an exit-gate management/ presence-detection loop system.

Minnesota state law specifies that automated crossing signals should activate at least 20 seconds before the train occupies the crossing.

I don't know if there is a requirement for how quickly the gates must be in the lowered position after the 20 second period begins.

-Larry Doyle

signalmaintainer Wrote:
-------------------------------------------------------

> That being stated, the gate you are referring to
> could have been an exit gate for vehicle traffic
> leaving the crossing. Exit gates will descend as
> soon as a train enters the island, if they have
> not already descended via the control from an
> exit-gate management/ presence-detection loop
> system.

It was an exit gate. And it isn't a particularly busy street. The quad gates and sidewalk gates are part of a "no horn zone" series of changes.

Rule 6.32 requires that trains that have been stopped or going slow before a crossing must not increase speed such that they will enter the crossing until the gates are fully down. From the description, this is a close but legal operation.
This is because grade crossing electronics try to predict the approach time for trains of varying speeds and they will "time out" and raise the gates if a train is detected to have stopped while approaching the crossing (so as to let road traffic go). A sudden start can put a train in a crossing before the gate circuits reconginze the re-started movement and run through the timing cycle.

railstiesballast Wrote:
-------------------------------------------------------
> Rule 6.32 requires that trains that have been
> stopped or going slow before a crossing must not
> increase speed such that they will enter the
> crossing until the gates are fully down. From the
> description, this is a close but legal operation.
> This is because grade crossing electronics try to
> predict the approach time for trains of varying
> speeds and they will "time out" and raise the
> gates if a train is detected to have stopped while
> approaching the crossing (so as to let road
> traffic go). A sudden start can put a train in a
> crossing before the gate circuits reconginze the
> re-started movement and run through the timing
> cycle.

This may be right on the money as the train was moving just a bit faster than walking speed when it entered. Too fast to jump aboard but clearly not at speed or accelerating.

john1082 Wrote:
-------------------------------------------------------
> railstiesballast Wrote:
> --------------------------------------------------
> -----
> > Rule 6.32 requires that trains that have been
> > stopped or going slow before a crossing must
> not
> > increase speed such that they will enter the
> > crossing until the gates are fully down. From
> the
> > description, this is a close but legal
> operation.
> > This is because grade crossing electronics try
> to
> > predict the approach time for trains of varying
> > speeds and they will "time out" and raise the
> > gates if a train is detected to have stopped
> while
> > approaching the crossing (so as to let road
> > traffic go). A sudden start can put a train in
> a
> > crossing before the gate circuits reconginze
> the
> > re-started movement and run through the timing
> > cycle.
>
> This may be right on the money as the train was
> moving just a bit faster than walking speed when
> it entered. Too fast to jump aboard but clearly
> not at speed or accelerating.

In that case, the crew should have waited at least 20 seconds from the time the crossing activated before entering the crossing. I believe otherwise is a rules violation. If not, then it's a violation of common sense.

signalmaintainer Wrote:
-------------------------------------------------------
> > This may be right on the money as the train was
> > moving just a bit faster than walking speed
> when
> > it entered. Too fast to jump aboard but
> clearly
> > not at speed or accelerating.
>
> In that case, the crew should have waited at least
> 20 seconds from the time the crossing activated
> before entering the crossing. I believe otherwise
> is a rules violation. If not, then it's a
> violation of common sense.


Try rereading all the replies. The gate in question was an exist gate of a 4 quad gate setup, and as such worked correctly.

Gates on the KP in Ellsworth, KS come down 30 seconds before the train goes thru the crossing. upkpfan

Back in the 1970's I worked at an avionics factory on Arden Dr. in El Monte CA (east of Los Angeles) near the SP line to Colton. My collegues would observe the gates coming down far in advance of a through freight or Amtrak train, but not come down for the local switcher until it was almost to the crossing and ask how the gate system could tell how fast the trains were moving. After checking with some signal experts (probably at Orange Empire) I advised them that the signal controls used an audio-frequency Doppler shift detector system, and this seemed to satisfy them. But it didn't stop my co-workers who lived to the south of the plant for "blaming" me (as the unofficial spokesman for the railroad industry) when a freight got stuck on the grade crossing and made them late for work.