The Many Aspects of Railroad Signals

I don't know much about signals, but all of those are a variation of "green over red," whether it's one green, two green, all green, or semaphore position.

645 posted:

Hey GP 40 - you should seek out the set of books that Penn Central issued to operating employees as one can compare how PRR position light and NYC color light signals displayed the same aspect. This was done to help familiarize employees of one road when they had to operate in the other road's territory. 

     

There's also a book four called "Learning the signal indications" which combines the contents of books two and three as a quiz to see what signal aspects an employee understands. Apparently there was never a book one issued.

And before someone asks - no, I'm not sure how/if the New Haven got their own book. Were NH signals similar enough to the NYC color light signals so book three could be used for the ex-NH lines? Remember PC tried to prepare for the merger in advance and the New Haven was not originally going to be a part of it. NH joined PC a year after PRR/NYC merged so PC most likely did not issue a new book for NH signals.

Some of this is becoming a moot point on today's railroads as they standardize on one type of signal which is being sped up thanks to the PTC mandate. Soon we won't have position lights or NYC tri-light signals on the mainlines. Enjoy them while you can...!

Thanks for the suggestion 645. I do have copies of those booklets (and many others) in my personal library. I consider myself very conversant with most signal systems used by American railroads. I was merely attempting to point out how one indication may be conveyed by many different aspects. One must be cautious though, especially when dealing with Color Light Signal aspects such as red over red over yellow, as this particular aspect was "Slow Approach" on one property and "Restricting" on another. Same holds true for red over yellow aspect,  "Medium Approach" on one railroad and "Restricting" on another. Although identical aspects, they convey completely different information as to what speed is permissible to operate and the condition of the block, dependent entirely on the rules in effect on the territory the train is operating over.

FWIW.......In my humble opinion the Color Position Light systems were/are the most informative, not to mention the best looking....

C.J.

It seems UP is not replacing the "NYC" style triangle type signals along the Glidden Sub west of Houston TX.  I think these were put in in the 1980-90 range.  However, searchlights are becoming more rare than whooping cranes.  They are being replaced with straight tri-color with sun hoods.

Dominic Mazoch posted:

It seems UP is not replacing the "NYC" style triangle type signals along the Glidden Sub west of Houston TX.  I think these were put in in the 1980-90 range.  However, searchlights are becoming more rare than whooping cranes.  They are being replaced with straight tri-color with sun hoods.

That's because the "searchlight" type of signals have moving parts, plus are NOT PTC compliant.

This youtube link will take you to one of the better (and brief) signal demonstrations I have found.

https://www.youtube.com/watch?v=K8zrZ0Us6r8

I have to admit I haven't checked the video against each road's book of rules to see if every aspect in the video is correct.

Signal aspects (the lights and/or blades displayed on signals) have consistently been inconsistent.

I've got a set of 114 training flash cards from the CPR from way back when with regular and dwarf signals and the descriptions of each written on the back. Funniest thing... they came to me in a red tin box with braille on the top.

I acquired a Southern Railway Union Switch and Signal Company red over yellow dwarf signal at a flea market in Charlotte, NC some years ago. VERY heavy diecast housing and base. According to my Southern rule book, this is a slow approach, being prepared to stop, aspect.

SteamWolf posted:

I've got a set of 114 training flash cards from the CPR from way back when with regular and dwarf signals and the descriptions of each written on the back. Funniest thing... they came to me in a red tin box with braille on the top.

 I remember those.....  Often referred to as speed signals... Some of  us north enders  spent most of our careers on train order territory  and complained that we never worked in  signal territory and therefore didn't really  have to know all the signals.

Rule instructor response... You better get them memorized because not only will they be  on the rule test , you have to get  them all correct.... If not you fail  . pretty straightforward....  The signal do have some logic in  that  one signals leads to another.   And as with anything railway related, always exceptions.

What is inrtesting is that is DIVERGING APPROACH and APROACH DIVERGING!  To me that would be confusing!

Dominic Mazoch posted:

What is inrtesting is that is DIVERGING APPROACH and APROACH DIVERGING!  To me that would be confusing!

You get the Approach Diverging: Proceed preparing to take diverging route beyond next signal at prescribed speed ...

...before the Diverging Approach: Proceed through turnout(s) at prescribed speed preparing to stop at next signal. If exceeding medium speed immediately take action to reduce to that speed.

Nothing confusing if you read the definition.

Thanks for diverging and clearing up the rules.

On the CPR flash cards there seems to be a LIMITED SPEED yellow triangle on some of them.  PRR used a like triangle, even though they used PL aspects.  Did anybody else used the triangle.

With the coming of PTC, are the railroads headed towards speed or route type signaling?  Or it just depends on the railroad?

Keep whatever they have. There is no need to change.

What's really puzzling to me though after thinking about it for a while... with all this technology we have now like GPS, supercomputers the size of your wallet and multifunction TFT displays making up the dash of the driver's location, there's not (AFAIK) a way to upload signal positions in real time to the driver except to look out the window at the lights on the post. Someone needs to make some money off this!

SteamWolf posted:

What's really puzzling to me though after thinking about it for a while... with all this technology we have now like GPS, supercomputers the size of your wallet and multifunction TFT displays making up the dash of the driver's location, there's not (AFAIK) a way to upload signal positions in real time to the driver except to look out the window at the lights on the post. Someone needs to make some money off this!

So,,,,,I'm guessing that you are not aware of the cab signal systems, such as that installed by the PRR in the 1930s, nor the can signal system on the UP, installed back in the 1940s. Both are still in use today.

Did CNW also have cab signals?  But was it a different system than UP.

Dominic Mazoch posted:

Did CNW also have cab signals?

Not really. The C&NW ATC system had/has only two aspects "CLEAR" and "RESTRICTING". Thus, when the "warning alarm" sounds and the green light changes to the red light, the Engineer has so many seconds to: 1) apply the brakes, and 2) reduce speed below something like 17 MPH. Otherwise the ATC system puts the brakes on in a penalty application.

 But was it a different system than UP.

Totally different.

Big Jim posted:

Dominic Mazoch posted:

What is inrtesting is that is DIVERGING APPROACH and APROACH DIVERGING!  To me that would be confusing!

You get the Approach Diverging: Proceed preparing to take diverging route beyond next signal at prescribed speed ...

...before the Diverging Approach: Proceed through turnout(s) at prescribed speed preparing to stop at next signal. If exceeding medium speed immediately take action to reduce to that speed.

Nothing confusing if you read the definition.

Now, let's chase this with a little bit about "signals in advance of..." and "signals to the rear of..."  

Bruce Chubb excellent Rail Road Craftsman December 2015 page 60 article  discusses: In advance of, In approach of, and In the rear of signal terminology.   If someone has a way of posting those paragraphs (without violating copyrights) maybe they can be posted here.

By the way, Dr Chubb said more signal article would start in late summer/early fall time period.  Worth watching for articles.

Rob Leese posted:

..." and signals "signals to the rear of..."  

Man! You're going the wrong way!!!