In Tuscola,IL on the UP main, The signal gaurding the diamond is your standerd 3-light signal. the question is, there is a small, 1-light signal down the mast from it. I have only seen it lit once, and it was yellow, and the other signal was also yellow. The other signal has been yellow at many other times, but that particular time was the sole occasion it was lit
Was the lower yellow flashing?
If so, it was a proceed at restricted speed, prepared to stop at the next signal.
If both were yellow, dont have a clue…
Ed
Looking through UP’s signal rules, the only thing I can find that might explain this is shown under Restricting signals. Just another variant of them, instead of a lunar signal, lower flashing red, or whatever.
Which direction is this signal facing…for eastbound or westbound traffic or in both directions?
The one time you saw the bottom signal lit, was there a CSX train on the circuit?
My guess, and it is only a guess is that this is a signal for a diverging movment. If you recall, Crazy One, at one time there was a very interesting crossing involving the IC, UP, and CSX, all converging at the tower. Several years ago the crossing was simplified with the CSX joining the UP east of town and eliminiating the triple crossing. Thus, the CSX trains had to enter the UP tracks and then diverge after going thru town and crossing the IC (CN).
Ed, perhaps you can help me out here as my signal rule awareness is lacking, but I think if there is a diverging route then there must be two or more signal masts…the bottom one gives the lineup for the diverging route. My guess is the signal that you observed would have been red/yellow or lunar, meaning diverging approach (or diverging restrictive). Perhaps a bit more info is available. The CSX route is unsignalled, so the routing would be to diverge and proceed at restrictive speed, being able to stop within a certain distance.
ed
The was no CSX train Nearby.
The signal is for westbound traffic.
The CSX route is signaled, but only in Decatur,Tuscola,Metcalf, and Chrisman, all for diamonds except for Decatur.
Indication: Yellow over Yellow
I did notice a bunch of MoW equipment go by shortly after seeing the signal. Could this have anything do do with it?
CD,
As Ed has pointed out, the lower signal generally means a divergence AND slow speed. Was there a switch past the diamond? If not, then the lower yellow probably meant slow or yard speed, which fits your MOW train on the track.
MP173, (the other Ed)
The ones down here that have two signal head on a single mast are for just the purpose you described, the top signal protects the through route, the lower one the diverging route.
Flashing red is the usual indication of the diverging route being lined, but we have one that uses a steady lunar also.
Flashing yellow on any of the signals means restricted speed, prepared to stop short of the next signal or switch.
Ed
On NORAC, Yellow over Yellow is an Approach Slow - Proceed approaching the next signal at slow speed.
Nick
To deiscribe the daimond in Tuscola:
The CSX-UP mains diverge to cross the CN/IC line and passing track
Yellow over Yellow on the UP as far as I know is:
RULE 245C - Approach Medium - Proceed, Speed passing next signal must not exceed 30 MPH. Source: Union Pacific System Timetable No. 6, May 15, 1988 Reference: http://www.lundsten.dk/us_signaling/aspects_up1988/index.html
To slightly change the subject…Tuscola was a great place when they had the tower, and all three routes which converged at the tower and a small creek, if I recall correctly. I will have to get my photos out and see.
ed
The creek is still there
On the Union Pacific a Yellow over Yellow is Approach Diverging. Proceed prepared to take the diverging route at the next signal, not exceeding the prescribed speed thru the turnout.
I know of a few places a signal like this is used. When the route lined up is the normal route, the bottom, single head remains dark. When the diverging route is lined up the bottom head lights up to give the approach diverging aspect.
That is the system standard. Not working that area, the signal could be a holdover from previous owners and it’s name and indication would be covered by local instructions.
Does the next signal govern entrance to a siding, or other diverging track, by chance?
Jeff
Yeah that’s diverging signal for us. We have them around Tower 55 here in Ft. Worth.
Sometimes they are lunar signals (white)