General Discussion

Each railroad of course did standardize to one signal system.  But as road merged and merged and merged so did the maze of signal systems...

A single head have one or more lens....

Multi head on mast...one farthest to the right governs the track you are on unless otherwise stated in the book of rules or timetable instructions.

Multi head on signal bridge, the one closest to above your track governs your move unless otherwise stated in the book of rules or timetable instructions.

Multi heads, one above the other, see book of rules and or timetable instructions.  Could be home signal, could be disant apporach signal, could be any number of reasongs depending on railroad and its proclivities...

Best way to understand is to understand the history of the stretch of track you are looking at, the operations of the various railroads which operated that track, thier signal systems, and today's owner and its signal systems rules and regulations.   In other words, too many heads have brought the signal system to where it is today!

CShaveRR:

An operating employee had better know the signals for the territory he operates in. If one operates over more than one territory, then one had better be multilingual! I am not fluent in CPL, but were I to travel to B&O country I would carry my dictionary (CORA guide) with me for quick reference.

 

Carl,

Ever look at a NORAC book?   135 aspects and I had to know them all.    Luckily most follow a pattern, particularly the Pennsy based position lights, so they are somewhat easier to remember. 

At one point I was qualified over portions CSX, NS, Conrail, & SEPTA. 

Nick

Hi traingang.where have you guys been?? anyway on Csx the most lights and signal heads you will find would  be on signals near yards and crossovers.On the cpls the signal can also depend on which lunar aspect(top and bottom) is lit as well.That is if the signal has any lunar lights attached.

stay safe

Joe

No, Nick, I haven't had the pleasure of looking at a NORAC rule book (I'm sure I could spend hours on Larry's link!). The CORA book contains applicable signals for each of the railroads in the area, and at least two railroads (NS and IHB) are governed by NORAC, so I've got some NORAC signal pages (possibly modified, in IHB's case).

I've been too long off transfer runs to remain qualified in all of the places I've been, but a couple of familiarization trips would be all I'd need, I think. I wish I could just go as an observer, just to see some of these places before I pull the pin.

Sorry to have caused any confusion with my CSX link - it was just one that came up on Google, as did all of the others (although I have the NORAC saved on my computer someplace, too).  I think it did reference Florida.

The point was simply to illustrate why there are multiple heads. As was pointed out, everybody is a little different, enough so that even today there can be issues (else Carl wouldn't need his CORA book). 

That said (and as someone did point out), there really is a certain level of logic involved, even across railroads.  Where a specific color is on the mast, relative to the other heads, as well as the colors displayed by other heads on the mast (as modifiers), starts to make sense if you understand the underlying rationale - which can be a challenge as well.

Even with that, the timetable sometimes modifies the meaning of an aspect for a certain locale.  F'rinstance, while NORAC specifies "restricted speed" as 20 mph, 15 in an interlocking, our timetable specifies 10, and 5 at the station platform, for our Rule 98 territory, IIRC.  I'd have to go dig the rulebook out of my grip, which is in the back of the truck, which is backed into the garage.  I don't feel like moving it right now...