Someone explain RR signals to me!?

[Anonymous]

Greetings,

I've been trying to figure out what lights (signals) would be good for my layout. I've been observing the ones in my area but I don't quite understand them and what they mean. Could someone please explain dwarf signals, tower (bridge) and other signals to me? I know they have Red, Yellow and green as options but what does each color mean and what are the usual applications for them?

Thanks a bunch!
-Dale

[ndbprr]

Same as traffic lights. Blinking red light on signal usually means train on a grade can continue prepared to stop at a speed usually not to exceed 10-15 mph. turnout - one signal for each track indicating permission to proceed. Usually the top one is the straight route. Dwarfs - used in terminals with many track cnoices to keep costs down. All signals use the sme rules on each railroad regardless of location and size.

[dehusman]

They are NOT the same as traffic lights.

Green signals are called clear signals.
Yellow is associated with approach signals.
Red is stop or a placeholder.
White or Lunar means slow or restricted speed.

Yellow lights in an indication tell a train what to expect at the next signal.

For example a yellow or yellow over red is an approach indication which means the train has to immediately reduce speed to 30 mph and prepare to stop short of the next signal.
A flashing yellow or flashing yellow over red is an advance approach that means to reduce to 40 mph and be governed by the next signal (which is usually an approach signal).
If the signal has two heads and the red one is on top, that means the train will take the diverging route. For example if the train is coming up to a siding where it will stop, it might get a yellow over red, approach, if its going down the main or a red over yellow, diverging approach, if its going in the siding.

It will try and remember the site that has a lot of signal info on it.

Dave H.

[dehusman]

Here are some links to web pages with signal info:

http://www.spikesys.com/Trains/Signals/

http://www.warplink.com/~kencan/absolute.htm

http://home.comcast.net/~candcb1/idx_rules.html

http://sptco.railspot.com/Signals_&_Indications/Signals_&_Indications_1960.htm

Dave H.

[Anonymous]

Better yet, go to the library or a rail historic society and get a timetable. They always have a signal guide and breif operational rules section in them. What Dave H above said is true, but it's not an absolute as most roads had their own little quirks and special meanings along with signal heads used in multipules. There was and is no industry standard is a nice way of putting it. FRED

[Anonymous]

Very helpful thanks!

[Anonymous]

Here's another one.

http://www.vcn.com/~alkrug/rrfacts/signals/signals.htm

Rob

[ndbprr]

Let's see Green - Tr Light -go, signal Ok to proceed
Yelow - tr light caution (light changing) Signal be alert for next signal
red stop Sure sounds the same to me

Are the names the same? - Nope. Do the serve the same function Yep.
Rules not the same. The basic answer is till valid. Same as a traffic light.

[Anonymous]

Ok, what's a yellow over red mean then ndbprr? How about a yellow over green over red? A red doesn't alway mean to stop. Sometime it means to stop and proceed at limited speed. I'm glad your not a engineer, you would get someone killed. FRED

[ndbprr]

I said in my original post that red meant stop in most cases. For a newbie who doesn't understand signals lets throw complex aspects at him right away so he doesn't understand the simple stuff first. Those questions can follow later once the basics are understood.

[dehusman]

Yellow doesn't mean the signal is changing, it is telling what is going to happen at the next signal. Other than they use the same colors and are lights (in most cases), they are different in what they tell you.

Dave H.

[vw-bug]

The SIMPLE truth is
Green=Go
Yellow=Proceed to next signal with caution
Red=Stop

It can get much more complicated but that is easiest way to think about with getting into the multi-signal aspects.

[wp8thsub]

"The SIMPLE truth is
Green=Go
Yellow=Proceed to next signal with caution
Red=Stop"

The unfortuante facts are that it's not that simple. I agree that throwing too much at a newcomer can be discouraging, but oversimplification isn't always a help either.

"Green=go"

This is the closest parallel to a traffic light. Most railroads call a single green indication "clear."

"Yellow=Proceed to next signal with caution"

Not really. Yellow tells you what you should be prepared to do at the next signal. With traffic lights, yellow is a warning to clear the intersection because the light is about to turn red. It doesn't necessarily imply what you're to do at the next intersection.

"Red=Stop"

Sorta but not really. Red gets sticky because different rules apply depending on whether the signal mast has a number plate or a letter "A" or a "G" or... Other than an absolute signal in CTC territory red doesn't have a traffic light equivalent. A permissive red signal functions more like a stop sign but not entirely, come to a complete stop (in most cases) then proceed at restricted speed to the next signal.

There is no traffic light that equates to a lunar indication. The railroads I'm familiar with use lunar (roughly proceed at restricted speed not exceeding prescribed speed through turnout).

Most railroad applications don't just have single heads either, which forces one to learn what the combinations of reds, greens and yellows are. Learning enough to get by on a model railroad really isn't hard, though. Two of the layouts I operate on regularly have full CTC and it normally doesn't take long for newbies to become comfortable with how to read the signals. Finding a layout with CTC or ABS is the best way to learn how to work with signals if there's one close to you that you can visit.

[der5997]

Depends how modern you want your info to be. Kalmbach books published "All about signals" in ( I think) 1957. reprinted it at least up to 1983, which is probably about when I got my copy. It's a compilation of MR articles by John Armstrong. If you haven't any of John's stuff in your RR library, this is a good one to meet your needs. 26 pages, so not a tome. Try it, why not? [:D]

[AltonFan]

Every so often, Model Railroader publishes a chart with signal aspects illustrated. I seem to remember a chart like this with a Gordon Odegard article back in the 1980s.

[ShaunCN]

I have always wondered about railroad signals as well. Can any one tell me a website on Canadian National signals. Your help is appreciated.
ShaunCN

[Anonymous]

QUOTE: Originally posted by AltonFan

Every so often, Model Railroader publishes a chart with signal aspects illustrated. I seem to remember a chart like this with a Gordon Odegard article back in the 1980s.

Sorry, but that don't really work. As I stated already most companies have their own rules about signals. I have signal sheets from the ATSF (1958), the Illinois Central, and the Missouri North Arkansas. All three books have some signal sets that are the same, and some that are not the same. You all can argue about it all you want, but the books are the final authority. Signals should be modeled after the prototype you run from their printed manual. If you freelance then green can mean stop and red mean go and yellow mean backup quick. FRED

[AltonFan]

FRED,

For a newbie looking for a basic overview of the subject, an article such as the one I mentioned would probably be more than enough.

I can't imagine though, that there would be very big differences between the several railroads' rulebooks on this. After all, if a railroad operated through a major gateway such as Chicago or St. Louis, at some point they would have to operate over another line's tracks, and have to be familiar with their signals. I'm sure that the regulators imposed a degree of uniformity on signaling conventions as well.

If somebody really wanted to know about signaling, they would need to consult the treatise The Rights of Trains, which I understand is the definitive work on the subject.

[Anonymous]

The websites that were referred to me were great! I'm not looking for exact info, I just wanted to get a general idea so I could do some fairly simple wiring with the lights to make them work at a fairly realistic level. It is interesting to know that many lines have different methods to using the lights.

Thanks to all!
-Dale

[dknelson]

Andy Sperandeo has a recent article called "Understanding Railroad Signals" in the December 2002 MR (page 104). It is a good clear explanation. I would also recommend the John Armstrong articles on All About Signals in the June and July 1957 Trains. Armstrong goes into how signal systems interract. Kalmbach reprinted that article series as a pamphlet that I have seen for sale at swap meets. More recently the May 1992 Trains has an article on signals.
If you get ahold of a real railroad rulebook you will quickly see that signals are more complex than traffic lights especially once they start stacking them up, say at a crossover or a siding, or once you introduce signals that flash versus steady, and so on.
Dave Nelson

[BR60103]

For ShaunCN:
Bytown Rly Society publishes th Canadian Trackside Guide every year (about March). It contains a six page section on signals, and I think the Canadian ones are now standard. You may be able to find a copy in a hobby shop.
The single light signals are pretty straightforward. It's when you get 2 or 3 lights stacked up and flashing that you get indications like "Pass through the interlocking at a limited speed, then proceed at medium speed, but slow down at the donut shop for your takeout."
There was a heated debate with name-calling in the Trains forum a few months ago, with prototype railroaders arguing over signal indications on their various roads.

[dehusman]

Rights of trains is definitive on train orders, not signals.

Dave H.

[AltonFan]

QUOTE: Rights of trains is definitive on train orders, not signals.

Dave H.

I stand corrected.