Western Railroad Discussion > What does a flashing yellow mean?

Hi,

I saw a flashing yellow signal on track one today in LaFox and I've never seen that before. What does it mean? When the block was occupied, the signal would be red. Later the signal would turn to flashing yellow and stay that way until a train approached. When it got close, the signal would turn to green and the sequence would repeat. In Geneva and West Chicago, the signals remain a constant yellow instead of flashing.

Thanks,
Kevin Kuehl
kevinkuehl@yahoo.com
http://rail.ktlx.net

a flashing yellow signal train crews call a flasher means advance approach on the UP but on the BNSF it means Approach Medium!!

it means it is an intermediate signal where the next signal maybe yellow going into a siding which means they have a red at the other end of the siding and that th switch is lined for another train coming into the siding!!!
For Example:
amtk 524 advance approach mowry out!!!
means 524 will be crossing over at CO031 Cherry and heading up the Niles Sub!!!

hope that helps

Paul Jansson

At Lafox, was it the signal by harley road going west, or the signal by Brundage Road going east? Could have two different meanings, ither there is a train in the block two blocks ahead, or the train coming on Track on is lined up to cross over at peck or Elburn. If it was the west bound signal, then the train ahead was still in the block between Elburn and Merideth.

The signal you see at geneva for westbound movement will always display yellow or approach until the dispatcher lines train up at Peck Y038. Since its the only signal before Peck. The same signal for eastbound movement will always display flashing yellow or advance approach until its lined up. What see is also the continue upgrading from the old CNW signals to UP signals.

LCW Wrote:
-------------------------------------------------------
> If it was the west bound signal,
> then the train ahead was still in the block
> between Elburn and Merideth.

Thanks. It was the west bound signal.

Kevin Kuehl
kevinkuehl@yahoo.com
http://rail.ktlx.net

LCW Wrote:
-------------------------------------------------------
If it was the west bound signal,
> then the train ahead was still in the block
> between Elburn and Merideth.

A small correction, that would mean a trin was in the block between MP 46 (francis road) and CP y)48, Merideth.

9.2.4 Advance Approach

Proceed prepared to stop at second signal. Freight trains exceeding 40 MPH must immediately reduce to 40 MPH. Passenger trains may proceed, but must be prepared to pass the next signal not exceeding 40 MPH.

When signal governs the approach to a control point with a 40 MPH turnout speed be prepared to advance on normal or divergent route.

LCW Wrote:
-------------------------------------------------------
> At Lafox, was it the signal by harley road going
> west, or the signal by Brundage Road going east?
> Could have two different meanings, ither there is
> a train in the block two blocks ahead, or the
> traincoming on Track on is lined up to cross over
> at peck (you cannot cross over from track 1 west
> bound at Elburn). If it was the west bound signal,
> then the train ahead was still in the block
> between Elburn and Merideth.

What I always wonder is why they don't display a
yellow over yellow (approach diverging), in the case
when the train is looking at a signal that governs the
approach to a turn out when the train is
lined through the turn out, and
eliminate the guess work?

Maybe it is because this is old territory and the
signals just have not been upgraded to the union
pacific system wide standard yet?

I suppose we can conclude that the speed through this
turnout is 40 mph?

Are there also examples of 40 MPH turnouts on the UP
system, with signals governing the approach to them which
display a yellow over yellow, approach diverging when the
switches are lined for the divergent route at the turnout?

hobojaks Wrote:
-------------------------------------------------------
> What I always wonder is why they don't display a
> yellow over yellow (approach diverging), in the
> case
> when the train is lined through the turn out, and
> eliminate the guess work?
>
> Maybe it is because this is old territory and the
>
> signals just have not been upgraded to the union
> pacific system wide standard yet?
>
> I suppose we can conclude that the speed through
> this
> turnout is 40 mph?
>
> Are there also examples of 40 MPH turnouts on the
> UP
> system, with signals governing the approach to
> them which
> display a yellow over yellow, approach diverging
> when the
> switches are lined for the divergent route at the
> turnout?

The old CNW signals will display yellow over yellow, but the new UP system will display either:
Flashing Yellow (advance approach)/ Yellow (approach ) or Red -red-red, Red-red-lunar, red-flashing red (stop, stop and proceed pr restricting.

If your route is to cross over it will display two advance approaches and then the third signal will display the cross over indication (diverging clear, Diverging Aproach). In ATC territory, the cab signals will give you a pretty good idea of what route to expect at the control point. on teh former CNW the signals are kind of a patchwork of the old CNW (two block) and new UP (three block) signals so it really helps to know where you are at an what signals to expect.

it's not always on an intermediate signal as stated earlier. If you're following a train, you can get them two blocks behind the train you're follwing, even the A signals. Basically, if you're going down the track on greens you can encounter a Flashing Yellow, then the next signal is most likely going to be approach, then red at the signal after that. Unless the train is still moving away from you and it clears another block and gets you another Flasher.

ALso get flashers before the double yellows going into sidings.

YM

Flashing yellow in CTC - "Advance clear to stop"

Sparky Wrote:
-------------------------------------------------------
> Flashing yellow in CTC - "Advance clear to stop"


Unless the green bulb is burned out, then it will downgrade to the next restrictive indication.

hobojaks Wrote:
-------------------------------------------------------
> LCW Wrote:
> --------------------------------------------------
> -----
> > At Lafox, was it the signal by harley road
> going
> > west, or the signal by Brundage Road going
> east?
> > Could have two different meanings, ither there
> is
> > a train in the block two blocks ahead, or the
> > traincoming on Track on is lined up to cross
> over
> > at peck (you cannot cross over from track 1
> west
> > bound at Elburn). If it was the west bound
> signal,
> > then the train ahead was still in the block
> > between Elburn and Merideth.
>
> What I always wonder is why they don't display a
> yellow over yellow (approach diverging), in the
> case
> when the train is looking at a signal that governs
> the
> approach to a turn out when the train is
> lined through the turn out, and
> eliminate the guess work?
>
> Maybe it is because this is old territory and the
>
> signals just have not been upgraded to the union
> pacific system wide standard yet?
>
> I suppose we can conclude that the speed through
> this
> turnout is 40 mph?
>
> Are there also examples of 40 MPH turnouts on the
> UP
> system, with signals governing the approach to
> them which
> display a yellow over yellow, approach diverging
> when the
> switches are lined for the divergent route at the
> turnout?

The speed through the turn out is not established by the signal indication. Speed through tunouts are governed by the subdivision timetable in conjunction with subdivision general orders.

Yardmaster Wrote:
-------------------------------------------------------
> it's not always on an intermediate signal as
> stated earlier. If you're following a train, you
> can get them two blocks behind the train you're
> follwing, even the A signals. Basically, if
> you're going down the track on greens you can
> encounter a Flashing Yellow, then the next signal
> is most likely going to be approach, then red at
> the signal after that. Unless the train is still
> moving away from you and it clears another block
> and gets you another Flasher.
>
> ALso get flashers before the double yellows going
> into sidings.
>
> YM

I beleive thats is what I stated earlier that the Advance approach indication could have two meanings, either that you have caught up wiht the train ahead (fy/y/r) in which case you could conceivably run on a series of Advance Approaches if your speed were right, or it could inidcate a crosover movement at the third signal or control point (fy/FY/ R-g, FY/FY/R-y, fy/fy/R-FR)

The responces I have given thus far are also specifically in relation to the original post regarding the west bound Advance Approach at Harley Raod apprx. MP 41.3 on the geneva sub division.
though it if farily unusual (though not unheard of) for a west bound to be on track 1 at this location.

hobojaks Wrote:
-------------------------------------------------------

> Advanced Approach

Good one. Wrong. But a good one never the less.

LCW Wrote:
-------------------------------------------------------
> The responces I have given thus far are also
> specifically in relation to the original post
> regarding the west bound Advance Approach at
> Harley Raod apprx. MP 41.3 on the geneva sub
> division.

Yes, thanks. That's really what I was interested.

> though it if farily unusual (though not unheard
> of) for a west bound to be on track 1 at this
> location.

I was amazed. I not only saw UP 1995 + UP 2001 + UP 1988 headed west bound on track one but an earlier coal train too.

Kevin Kuehl
kevinkuehl@yahoo.com
http://rail.ktlx.net

LCW Wrote:
-------------------------------------------------------
"...
> though it if farily unusual (though not unheard
> of) for a west bound to be on track 1 at this
> location...."

Depends who is in the Dispatcher's chair :)

SWR

>it means it is an intermediate signal where the next signal maybe yellow going into a siding which means they have a red at the other end of the siding and that th switch is lined for another train coming into the siding!!!

Generally speaking, a flashing yellow signal will precede a yellow one, which precedes a red one. A double yellow will precede a red-over green or red over yellow for taking a diverging route. There are exceptions on the BNSF's Stockton Sub where a flashing yellow means the same as a double yellow, but these are being phased out.

On both the UP and BNSF, a yellow signal is called "Approach". However, a flashing yellow on the UP is "Advance Approach", while on the BNSF, it's "Approach Medium" (which is the traditional name for all railroads which used the Consolidated Code). A red over yellow is called "Approach Diverging" correction->"Diverging Approach" on the UP and "Approach Medium" on the BNSF. The two roads also differ on the names they use for yellow over green and yellow over flashing greem, although what you have to do is the same on both.

>For Example:
amtk 524 advance approach mowry out!!!
means 524 will be crossing over at CO031 Cherry and heading up the Niles Sub!!!

This isn't necessarily correct. If 524 is going to be taking a diverging route at Cherry, as in through one of the crossovers, then the preceding signal will be double yellow, "Approach Diverging". If 524 is not going to cross over to head up the Niles Sub, then the preceding signal could be flashing yellow, "Advance Approach". However, the UP has a habit of using red-over <whatever> to indicate that a train will be going through the reverse direction of a turnout whether facing or trailing. This is why you get a red over <whatever> when departing the station track westbound from Martinez. It's a converging route, but it's governed by a red over <whatever> signal. The SP practise was just plain <whatever> (i.e. green, flashing yellow, or yellow).

Unlike the BNSF, the UP doesn't use flashing yellow in advance of an indication for a diverging route, and the BNSF's practise of doing so is a carryover from the AT&SF, at least out here here California.

updispr Wrote:
-------------------------------------------------------
>
> Depends who is in the Dispatcher's chair :)
>
> SWR


True there is this one guy that seems to have a strange affinity for running trains the wrong way and really upsetting the old CNW types.

He doesn't seem to work around here too much anymore.

I haven't been west of the Elburn (Metra) Station station in a while. I had to kinda rack my mind to remember what lay in that great abbiss.

InsideObserver Wrote:
>
> Unlike the BNSF, the UP doesn't use flashing
> yellow in advance of an indication for a diverging
> route, and the BNSF's practise of doing so is a
> carryover from the AT&SF, at least out here here
> California.

UP does indeed use Flashing Yellow in advance of a diverging route. That is why I said it could indicate two entirely different situations (though the rule for the signal indication is the same either way).if you are in an area where the "new" UP signals are in effect you will have two Advance Approaches in advance of a diverging Clear.