The railroad signals discussion

[dadonatrain]

What am I doing right now? I’m sitting on the side of the Greenville, SC, station wishing I could ride a train! Anywhere! I don’t even care where!

I told my family years ago if they bury me instead of cremate me, I want my epitaph to be All things considered, I’d rather be on a train.

A freight engine pulling a half dozen cars just crawled by into the yard. It made me wonder what the signals mean. I know red from green but beyond that I have no idea what one yellow light means…In the distance over the two parallel through tracks there’s a single yellow light over each track.

 

[jis]

What am I doing right now? I’m sitting on the side of the Greenville, SC, station wishing I could ride a train! Anywhere! I don’t even care where!

I told my family years ago if they bury me instead of cremate me, I want my epitaph to be All things considered, I’d rather be on a train.

A freight engine pulling a half dozen cars just crawled by into the yard. It made me wonder what the signals mean. I know red from green but beyond that I have no idea what one yellow light means…In the distance over the two parallel through tracks there’s a single yellow light over each track.

Here's what the Norfolk Southern signals mean. I am afraid it is probably more complex than one would guess at first blush...

If there is further interest we should move this discussion to its own thread since Railroad Signalology can be a very absorbing and very very very lengthy discussion.

 

[dadonatrain]

Thx! I’d love to understand this better! I heard a fellow passenger tell me some time back that every railroad uses its own system and Amtrak engineers on LD routes have to know where they are to understand and follow the signals correctly! As soon as you set up a dedicated thread on signalology I’ll follow it!

 

[BlackDiamond]

Amtrak owned lines i.e. the NEC and several other Northeastern railroads use the NORAC (Northeast Operating Rules Advisory Committee) signal rules:
NORAC signaling (PDF)
This includes NJT, MBTA, Pam Am Railways and a few others.
Of course Amtrak trains operating on host railroads follow the host RR system.
OTOH Freight trains e.g. Norfolk Southern operating on the NEC have to follow Amtrak (NORAC) rules.

CSX has its own system
CSX Signaling

And so do BNSF and Union Pacific in the West.

 

[Jovet]

It made me wonder what the signals mean.

Welcome to the complex and enlightening (pun intended) world of railway signaling.

Signaling has evolved over the past 160+ years to keep trains from colliding into one another and also to ensure they don't go too fast where they need to slow down. There are two aspects (pun not intended) to railway signaling: the signal displays and rules themselves, and what those things actually mean to the train crew. Many of us never get that second part, since we're not on a train crew and we don't know that, for example, a crew knows a yellow signal at such-and-such place means X-Y-Z is going to happen and they'll be delayed an hour. But, the whole point of signaling is to make sure train crews have the info needed to operate their train efficiently yet safely.

Different railroads have always had their own opinions and situations about how best to utilize signaling and leverage efficiency. This is why there are many different signal systems across the U.S. I see others here have posted links to some of my signaling charts. (My website) Anyone who has looked at those files realizes that there are multiple sets of rules presented. This is because these railroads have a family tree of ancestor railroads, with crews experienced and trained on those territories with those signals. Changing the way signals work on a whim, or simply because of a merger, is both cost-prohibitive and rocks the safety boat. When you railfan an area and try to interpret signals, you must therefore know some history about the line you're looking at to know which set of signal rules to use. Most of us railfans enjoy soaking up this information, anyway.

US (and Canadian) train signals seem to be pretty intimidating to most people, but there is a method to them, even if it's not intuitively obvious. It's my opinion that Al Krug has written the best-ever explanation about how to learn and understand signals. His website disappeared years ago, but an archive of the main signal page can be found here: Al Krug Signals Page (Archive). I urge everyone to give it a read; hopefully you learn something.

 

[dadonatrain]

Jovet,

Thank you very very much! This is so cool! I even printed the Al Krug materials so I can carry them with me if I go out to see signals for myself!

 

[Jovet]

I even printed the Al Krug materials so I can carry them with me if I go out to see signals for myself!

You're quite welcome! Do keep in mind that page of Al Krug's is more of a "teach a man to fish..." thing versus a "give him a fish" type thing. Definitely read and study it before you go out. It should help you then understand and memorize the signal rules for a given railroad/location you encounter. If you have any questions, feel free to ask. I always say the best part of railfanning is there is always something to learn, and there are lots of knowledgeable people in the hobby.

 

[TinCan782]

From Trains Magazine ...
"There is more to understanding railroad wayside signals than simply “green means go, red means stop.” To appreciate what the signals you see along the track are telling you, you first have to grasp a few basic concepts."
https://www.trains.com/trn/train-basics/abcs-of-railroading/railroad-signals/

 

[TinCan782]

PDF from Trains Magazine - July 1957