The UP line south of town I cross often while I’m working. I’m guessing red means line ahead is occupied, green means go for it, but what does yellow mean?
Without knowing the particulars of that signal and the block that it’s governing, about all that is safe to say is that the train should expect to find the next signal set against it (red).
Check this out:
I’m pretty sure yellow means ‘slow ahead/caution’
Yellow is an approach when means to be prepared to stop at the next signal.
Are trains proceeding under an ‘approach’ indication in yard limits still required to travel at restricted speed? (They used to be on the CNW)
Hate to sound like a broken record but: generally red is stop, yellow is proceed with caution, and green is clear or go. But each railorad has its own signal system(s) and rules. While there is a General Code, each railroad also has its own book of rules. In this instance, check with local UP or national rail historical society(ies) members or other railfan groups for those who have these books…check flea markets, Ebay and other web auction sites, hobby shop bulliten boards,and train shows, and ads in Trains, Classic Trains, MR, et al, for this stuff, too. Everyone will have an answer and every answer may or may not be right for this given situation. There are even general knowledge books about signals and signal systems which might or might not be in a public library.
GCOR has signals as such…
Basic only, as pointed out, each railroad can introduce other rules.
Assume you are proceeding under signal indication.
Signals have aspect, (what color do they show or what pattern they show) and indication, (what they tell you to do or not do)
Red is stop, and means stop and hold.
Yellow is restricted or approach, (depends on the railroad), means pass this signal at restricted speed prepared to stop at the next signal.
Flashing yellow means pass this signal and the next at restricted speed prepared to stop at the following signal.
Green means proceed at timetable track speed.
With a solid yellow you will expect the next signal to be at least as restrictive as the yellow…its either going to be yellow or red.
Yellow is used to slow down trains following another train, or restrict speed in busy places like approaches to yards and such.
You should expect a red after a yellow, although you may see a series of yellows before a stop indication is received, and if the lead train clears the main, or whatever caused the need to reduce speed goes away, you may get a green, but you will pass at least 2 solid yellows before you see green.
This should help, its from the current GCOR.
Yes.
Jeff
And then there were the B&O color position lights (CPL’s), which had modifiers above and below…
You will find the following trade paper book to be a complete treatis on this subject, to wit: Brian Solomon, RAILROAD SIGNALING (Minneapolis: Voyageur Press 2003, 2010). Plus, you can carry it around on your train trips.
I have not seen or read this book but have heard nothing but good about it…forgot about it otherwise would have reccommended it…
I read it…it is a good book. The most important thing I learned is that railway signalling is not as easy and straightforard is traffic signals on roads. There are subtle (and sometimes not so subtle) variations from one railway to another. But one thing we can agree on…red never means “proceed at speed”.
NORAC is using the ninth edition now, but the Eighth Edition is still available on-line and includes color renditions of a number of signal aspects.
Of course, these are the NORAC aspects - every railroad has it’s little differences. Still most types of signals are represented there.
For a quick reference, you could print off the pages with the pictures on your color printer for quick reference. If you think you’ll use them a lot, take them to an office supply store and have them laminated…
Since the OP was asking about UP signals, here is chart of UP signals. Looks to be fairly current, but I didn’t look at everything on the chart, so I won’t say it’s 100% accurate. Also, local special instructions could change what is otherwise standard. It should give a good idea of what you see along the UP.
http://members.cox.net/tsimsig/UPRR%20Signal%20Rules.pdf
It also doesn’t show cab signal aspects in use. But, the casual observer won’t see them anyway.
Jeff
UP apppears to have thought out their signals at present to cover almost any situation. This reference may help persons to understand KPs Sunset second track signal references. Appears that a version of this could be used to standardize signals nationwide.