signals

[willy6]

as a model railroader i got a book on railroad signals so i could prototype my layout. my word,there is a butt load of different types. why doesn't the gov't standardize the railroad traffic lights like it does for the automobile?

[tree68]

If only traffic lights were simple - Travel around the country and you'll find dozens of variations on how traffic lights are used. Red still means stop, amber caution, green go, but I've seen places where the lights are sideways; on Tipperary Hill in Syracuse, the colors are reversed (green on top). Rules for left and right turns vary from state to state and locale to locale. One area gives you a special green arrow for left turns, another simply staggers the timing of the green lights so you can turn without opposing traffic. Sometimes they do that, then open things up and warn you to turn when it's appropriate. Most states now have right on red, but there are exceptions, even in those states.

So, the railroads own their own ROW. For whatever reasons, each developed their own applications of the basics, and used them pretty much throughout their system. Besides operating practices, there were/are semaphores (upper and lower quadrant), color, searchlight, position light, color position light, etc. Since only their own people used their tracks (mostly), they had full control of the situation. Of course, there may have been political issues as well.

Nowadays, with the reduction of big railroads to a half dozen plus, I think you'll find that there is standardization occuring, albeit slowly (those signals aren't cheap). I see the occasional item in the trade press about the last whatever signal being replaced on some line or another. Add to that NORAC and GCOR and the pieces are in place for an eventual nationwide standard for signalling. But there will always be those darned exceptions.

[wabash1]

The old southern railway had the easiest signal system in the land ( my opinion) hard to get it wrong green means run the wheels off the thing then we go to yellow slow down something is ahead . and red real slow looking for a problem. 2 reds stop go nowhere. IF you had 2 signals on 1 post the top always ment what you was doing on the main the bottom was for other than main. hence red over green diverging clear . or red over yellow diverging approach. simple and effective.

[Mookie]

ok - dummy me - I gotta ask - what's diverging - is it like merging?

Someday I am going to sit down and study up on BNSF signals - someday!

[CShaveRR]

A diverging route is one that leaves the normal route. I hesitate to use the word "straight" instead of "normal", because it isn't always the straight route. It's more like exiting the highway than merging into it.

[JoeKoh]

QUOTE: Originally posted by Mookie

ok - dummy me - I gotta ask - what's diverging - is it like merging?

Someday I am going to sit down and study up on BNSF signals - someday!

Mookie
Diverging is where a train will switch over to the next track at a crossover.It happens all the time here in Defiance.A train will bypass a track at the Harris rd crossover because a nother train is picking up cars from gm.Then it will go back to the other track at the spruce st or jackson ave crossovers.[8D]
stay safe
Joe

[Anonymous]

Diverging Clear, Up here known more as a "median to clear" You have to clear the crossover track known as the Median.

Median to clear is usually Red/Green/Red

The easiest signals by far are the searchlight signals, Those cover about 95% of all signals In Canada, its not often you see an oddball one.

Medain to clear are often used in CTC regions to pass slower moving Trains. Via Rail often uses a Median to clear to pass a slower moving freight train, Just beofre leaving the CTC region. They pass each other in the weirdest fashion, But thats CN, anyone will tell you they are screwed up anyways.

Would i be right in assuming the most Medain to clear or Diverging clear signals are found in CTC regions? I can't see hoe one could be used on the Regular ABS system.

[Mookie]

Mookie is printing like mad!

[dehusman]

The CN UCOR rule book I have defines that aspect (red over green over red) as Medium Clear (not Median to clear).

It appears that the CN UCOR is a speed signalling system. The signals indicate teh speed you should be going. Diverging signals are route signalling system that indicate speed and route. A diverging route is the route that leavs the track you are on, whether it be into a siding or through a crossover.

Dave H.

[wabash1]

Diverging clear is just that changing route. if you was leaving a siding yu would get a diverging clear or diverging approach. if you was on the main and taking siding and the siding was not signaled you would get a restricting ( in abs signal when leaving signal territory to dark territory the best signal you could get is restricting.) if the siding is signal and no train is in the sidng then you can get a diverging clear or diverging approach. remeber they wanted it simple. and after thinking a minute about what you said mookie i guess you could say merging and exiting ( if signaled siding) but if you want to talk railroad talk its diverging.